Check that Duramax Transfer Case!
- Thread starter Jim 5
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I should have been more clear.
Yeah, I know oil evaporation exists. I just have a hard time seeing it in transfer cases because I've been around 4x4s all my professional life and don't know of a single case of a significant loss of fluid due to the evaporation process... even on t-cases that got hot enough in day to day use that it turned the fluid black, and I had a LOT of experience with those particular full-time Borg Warner units.
Come to think of it, The t-case in my old Ford (which I have owned 23 of it's 24 years of life) has had 3 t-case oil changes, well four now. The intervals were approximately 60K, some of them lasting 5 years or more. No drop in level. The first two of those intervals were with conventional Dex III ATF, some with THF, the latest with a synthetic ATF.
Anyway, just wondering why the NP261/263 would be something speacial in this area?
Yeah, I know oil evaporation exists. I just have a hard time seeing it in transfer cases because I've been around 4x4s all my professional life and don't know of a single case of a significant loss of fluid due to the evaporation process... even on t-cases that got hot enough in day to day use that it turned the fluid black, and I had a LOT of experience with those particular full-time Borg Warner units.
Come to think of it, The t-case in my old Ford (which I have owned 23 of it's 24 years of life) has had 3 t-case oil changes, well four now. The intervals were approximately 60K, some of them lasting 5 years or more. No drop in level. The first two of those intervals were with conventional Dex III ATF, some with THF, the latest with a synthetic ATF.
Anyway, just wondering why the NP261/263 would be something speacial in this area?
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dnewton3
Staff member
Allow me to be clear, as well, please.
It is not I who says evaporation is a major issue, but rather, the indivual I interviewed.
I fully believe that some amount of evaporation takes place, but I think it get's overblown in many cases. It is true that these t-cases in this application (261/263 in the GM 2500, 3500 HD trucks) can get pretty darn hot, especially when towing heavy loads (the underhood heat is unworldly at times, and it pours out underneath past the drivetrain).
Further, when I spoke to him, Weinberg could not quantify the specifics of any transfer reman details, nor give me "averaged" data. In essence, he could not tell me how many miles were on the cases that he had seen that failed, nor what type service they saw. Therefore, we have NO idea how low the fluid was, on those xfer cases had been neglected. I submit that had they been adequately serviced (topped off with ATF before getting too low), they would have never failed in the first place, and subsequently never got to Weinberg's shop for his review.
That being said, it is my suggestion to fight this perceived heat-induced evaporation with a "synthetic" ATF, rather than using 5w-30 motor oil. Synthetic ATF gives excellent flow at cold temps (winter) by providing easy shifting of the case gears, yet also does an admirable job of resisting heat of summer towing.
On a related note, the "pump rub" fix I installed was very easy for those who can turn a wrench, and read; use the Merchant Automotive directions as a guide, and it can be done in about two hours with a friend, or perhaps a bit more by oneself.
It is not I who says evaporation is a major issue, but rather, the indivual I interviewed.
I fully believe that some amount of evaporation takes place, but I think it get's overblown in many cases. It is true that these t-cases in this application (261/263 in the GM 2500, 3500 HD trucks) can get pretty darn hot, especially when towing heavy loads (the underhood heat is unworldly at times, and it pours out underneath past the drivetrain).
Further, when I spoke to him, Weinberg could not quantify the specifics of any transfer reman details, nor give me "averaged" data. In essence, he could not tell me how many miles were on the cases that he had seen that failed, nor what type service they saw. Therefore, we have NO idea how low the fluid was, on those xfer cases had been neglected. I submit that had they been adequately serviced (topped off with ATF before getting too low), they would have never failed in the first place, and subsequently never got to Weinberg's shop for his review.
That being said, it is my suggestion to fight this perceived heat-induced evaporation with a "synthetic" ATF, rather than using 5w-30 motor oil. Synthetic ATF gives excellent flow at cold temps (winter) by providing easy shifting of the case gears, yet also does an admirable job of resisting heat of summer towing.
On a related note, the "pump rub" fix I installed was very easy for those who can turn a wrench, and read; use the Merchant Automotive directions as a guide, and it can be done in about two hours with a friend, or perhaps a bit more by oneself.
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Hey Dave. Wasn't hangin' this around your neck, necessarily ( : < ), just pointing out the flaws in the premise.
Before I'd buy into the "high heat evaporation" thing, I'd have to know what actual temps are being run. The BW 4406 in my F-150 goes down the road at about 150F (I had a sensor in it last summer to see if Synchro Max made any difference in oil temps... it didn't) or less in warm weather and that's similar to the other chain drive part-time t-cases I have tested, including one NP-208 (which is the closest to the t-case being discussed).
I'm open to the possibility that the NP-261/263 units run hotter that anything I've tested, though I kinda doubt it, but I remain a "Doubting Jim," that it would make any difference even if they did... mostly based on my earlier experience with the fluid-burning full-time Borg Warners used in the final years of the 1st Gen Range Rover. Again, they fried the oil and still didn't lose a significant amount. Also, automatic transmissions run even hotter than t-cases generally, and they don't lose significant amounts of oil due to evaporation. Ditto for PS systems and manual trans that run ATF.
I have not been able to find a power flow diagram for the t-case in question, but in most chain drive t-cases, the high range, two-wheel drive power flow is pretty much straight thru the high/low range planetary gear. Not much heat generation going on, I don't think. Yes, the t-case will run significantly hotter in low range, but again, would it matter? And most owners don't use 4-wheel for significant enough periods for that to be an issue anyway.
My mind is open but not changed. I suppose there is some relevance in using the old Sherlock Holmes adage, "After eliminating all other possibilities, whatever remains must be the truth," in this case but it doesn't sound sufficiently well investigated at this point.
Before I'd buy into the "high heat evaporation" thing, I'd have to know what actual temps are being run. The BW 4406 in my F-150 goes down the road at about 150F (I had a sensor in it last summer to see if Synchro Max made any difference in oil temps... it didn't) or less in warm weather and that's similar to the other chain drive part-time t-cases I have tested, including one NP-208 (which is the closest to the t-case being discussed).
I'm open to the possibility that the NP-261/263 units run hotter that anything I've tested, though I kinda doubt it, but I remain a "Doubting Jim," that it would make any difference even if they did... mostly based on my earlier experience with the fluid-burning full-time Borg Warners used in the final years of the 1st Gen Range Rover. Again, they fried the oil and still didn't lose a significant amount. Also, automatic transmissions run even hotter than t-cases generally, and they don't lose significant amounts of oil due to evaporation. Ditto for PS systems and manual trans that run ATF.
I have not been able to find a power flow diagram for the t-case in question, but in most chain drive t-cases, the high range, two-wheel drive power flow is pretty much straight thru the high/low range planetary gear. Not much heat generation going on, I don't think. Yes, the t-case will run significantly hotter in low range, but again, would it matter? And most owners don't use 4-wheel for significant enough periods for that to be an issue anyway.
My mind is open but not changed. I suppose there is some relevance in using the old Sherlock Holmes adage, "After eliminating all other possibilities, whatever remains must be the truth," in this case but it doesn't sound sufficiently well investigated at this point.
dnewton3
Staff member
Jim - I didn't take it as though you were hanging it on me; no issues there, my friend. Just wanted other people to know that I was quoting my source, and not taking that stand myself.
I tend to agree with you on the heat/evap thing.
To be fair to the source of the whole "use engine oil" thing, here is a link to his article:
http://www.rsgear.com/technical/articles/2007_03.pdf
I'll let you all read it and see if you come to the same conclusions I did.
He makes a lot of claims, but nowhere does he discuss details such as how "hot" is hot, how many failures he's seen, how much "maintenance neglect" played into the failures, no disucssion of lube properties, etc.
Another thing that I find odd is that if he's so convinced that using engine oil is "better" than ATF, then why the need to overfill by 50%??? He advocates using the engine oil because he believes it will resist evaporation "better", but then suggests overfilling the t-case to 3 qrts instead of the normal 2 qrts. If engine oil is the "solution", then why the need to over-fill? In other words, he's taking a "shot-gun" approach and throwing all manners of possible solutions to this, and not addressed the root cause; that of poor maintenance practices. If engine oil can solve the issue, why over fill? If engine oil will also evaporate, then I suppose you could overfill, but that would not stop the issue, it would only delay the point of running dry. In fact, if he advocates 50% more fluid, why not 50% more ATF; why the need for engine oil? To me, he is simply "swagging" it, and it shows in his complete lack of logic to the approach.
The 261/263 t-cases don't run any hotter than the rest of the rig, overall. When I was pulling my travel trailer a few years ago, across SD in the searing summer heat, I had the "normal" ATF in my Allison tranny, and in my t-case. When I stepped out to fuel up at a station, I got a small second degree burn on my bare leg from the cab-step (aluminum aftermarket) as I brushed my leg against it stepping down past it. (ouch! - lesson learned). It occured to me how hot the underhood air is. All that heat soaks into the drivetrain (tranny, xfer, etc) and all the way back, as evidenced by the fact that it can heat up the running boards that much. And yet, I had to issues with the tranny or t-case fluid levels during of after that trip. It's reasonable to think that during long heat soakings like that, all the drivetrain is near the same temps. The engine ran around 210 deg F, the tranny at around 190-200 deg F, and it's reasonable to think the xfer was right around the same. While hot (as my leg can attest), that really isn't "HOT" compared to a tranny. If the ATF can adequately protect the tranny, then it can adequately protect the xfer case. The rate of evaporation (probably pretty low, actually) is the same, because the heat is the same. What might vary a bit is the level because of total sump volume. The xfer case does not hold near the volume that the tranny does. Half-quart loss in the xfer case is more of an issue than in the tranny. (xfer case = 2 qrts volume; tranny is probably 12 qrts total volume). But the RATE of evaporation is the same, given the same heat load. As long as one checks the fluid leves with reasonable frequency, the equipment should not run dry.
I have since swapped in Mobil 1 ATF into the xfer case, and AutoTrans-5 (DA lubes) into the Allison. I simply wanted both a bit of temp protection, but also longer service OCIs. I still check the fluids annualy, but I don't change them (figuring on 100k for both). Perhaps they may eventually need a top-off, but I don't see a change due for quite some time. So far, I haven't needed a top off of either at all. BUT I STILL CHECK THEM!
My engine oil level typically drops about 2 qrts over an entire year (mostly after those hot summer pulls). That 2 qrt range represents the "full" down to "add" marks on the dipstick. I never add fluid; by the time I get that low, it's time for an OCI anyway (fall of each year). Also, added fluid would skew a UOA; I like to know how the oil ran without virgin help. If it ever got below the "add" mark, I most certainly would do the right thing and top off, but it never does, so I don't see the logic to the added expense of the top-off knowing an OCI is right around the corner.
My point is that fluid levels are the responsibility of the owner to keep track of. There are times when it's easy (dip stick, sight glass, etc) and times when it's more involved (pulling a level plug for a visual inspection such as the diffs and t-case). But in no way is the fluid level ever a fault of the lube. There isn't an owner's manual printed today that says "ignore this until it runs dry". There are some "fill for life" pieces of equipment, but I assure you if that is the case, the OEM did a LOT of statistical studies before they felt good enough to put that in print. The GM xfer case in question is a piece that is to be maintained, and fluid level checks and exchanges are "routine" PM as defined by the OEM.
I highly suspect that if a person used 5w-30 motor oil in those same t-cases (rather than the spec'd ATF), and neglected them to the point where they ran dry, the same ugly demise would have been the end result.
Also, to be fair to Weinberg, I've not heard of people having failures using engine oil in lieu of the ATF. OTOH, perhaps their extra 50% oil hasn't yet evaporated and/or they check it more often ...
Want some grand irony? The GM xfer case calls for ATF, and some people go "off the reservation" and use engine oil. Yet, there are some Harley riders that swear by the use of ATF, rather than the spec'd lube (essentially engine oil), in their primary cases. Talk about your "grass is greener on the other side" approach! Both cases are essentially link-plate chain driven boxes!
I tend to agree with you on the heat/evap thing.
To be fair to the source of the whole "use engine oil" thing, here is a link to his article:
http://www.rsgear.com/technical/articles/2007_03.pdf
I'll let you all read it and see if you come to the same conclusions I did.
He makes a lot of claims, but nowhere does he discuss details such as how "hot" is hot, how many failures he's seen, how much "maintenance neglect" played into the failures, no disucssion of lube properties, etc.
Another thing that I find odd is that if he's so convinced that using engine oil is "better" than ATF, then why the need to overfill by 50%??? He advocates using the engine oil because he believes it will resist evaporation "better", but then suggests overfilling the t-case to 3 qrts instead of the normal 2 qrts. If engine oil is the "solution", then why the need to over-fill? In other words, he's taking a "shot-gun" approach and throwing all manners of possible solutions to this, and not addressed the root cause; that of poor maintenance practices. If engine oil can solve the issue, why over fill? If engine oil will also evaporate, then I suppose you could overfill, but that would not stop the issue, it would only delay the point of running dry. In fact, if he advocates 50% more fluid, why not 50% more ATF; why the need for engine oil? To me, he is simply "swagging" it, and it shows in his complete lack of logic to the approach.
The 261/263 t-cases don't run any hotter than the rest of the rig, overall. When I was pulling my travel trailer a few years ago, across SD in the searing summer heat, I had the "normal" ATF in my Allison tranny, and in my t-case. When I stepped out to fuel up at a station, I got a small second degree burn on my bare leg from the cab-step (aluminum aftermarket) as I brushed my leg against it stepping down past it. (ouch! - lesson learned). It occured to me how hot the underhood air is. All that heat soaks into the drivetrain (tranny, xfer, etc) and all the way back, as evidenced by the fact that it can heat up the running boards that much. And yet, I had to issues with the tranny or t-case fluid levels during of after that trip. It's reasonable to think that during long heat soakings like that, all the drivetrain is near the same temps. The engine ran around 210 deg F, the tranny at around 190-200 deg F, and it's reasonable to think the xfer was right around the same. While hot (as my leg can attest), that really isn't "HOT" compared to a tranny. If the ATF can adequately protect the tranny, then it can adequately protect the xfer case. The rate of evaporation (probably pretty low, actually) is the same, because the heat is the same. What might vary a bit is the level because of total sump volume. The xfer case does not hold near the volume that the tranny does. Half-quart loss in the xfer case is more of an issue than in the tranny. (xfer case = 2 qrts volume; tranny is probably 12 qrts total volume). But the RATE of evaporation is the same, given the same heat load. As long as one checks the fluid leves with reasonable frequency, the equipment should not run dry.
I have since swapped in Mobil 1 ATF into the xfer case, and AutoTrans-5 (DA lubes) into the Allison. I simply wanted both a bit of temp protection, but also longer service OCIs. I still check the fluids annualy, but I don't change them (figuring on 100k for both). Perhaps they may eventually need a top-off, but I don't see a change due for quite some time. So far, I haven't needed a top off of either at all. BUT I STILL CHECK THEM!
My engine oil level typically drops about 2 qrts over an entire year (mostly after those hot summer pulls). That 2 qrt range represents the "full" down to "add" marks on the dipstick. I never add fluid; by the time I get that low, it's time for an OCI anyway (fall of each year). Also, added fluid would skew a UOA; I like to know how the oil ran without virgin help. If it ever got below the "add" mark, I most certainly would do the right thing and top off, but it never does, so I don't see the logic to the added expense of the top-off knowing an OCI is right around the corner.
My point is that fluid levels are the responsibility of the owner to keep track of. There are times when it's easy (dip stick, sight glass, etc) and times when it's more involved (pulling a level plug for a visual inspection such as the diffs and t-case). But in no way is the fluid level ever a fault of the lube. There isn't an owner's manual printed today that says "ignore this until it runs dry". There are some "fill for life" pieces of equipment, but I assure you if that is the case, the OEM did a LOT of statistical studies before they felt good enough to put that in print. The GM xfer case in question is a piece that is to be maintained, and fluid level checks and exchanges are "routine" PM as defined by the OEM.
I highly suspect that if a person used 5w-30 motor oil in those same t-cases (rather than the spec'd ATF), and neglected them to the point where they ran dry, the same ugly demise would have been the end result.
Also, to be fair to Weinberg, I've not heard of people having failures using engine oil in lieu of the ATF. OTOH, perhaps their extra 50% oil hasn't yet evaporated and/or they check it more often ...
Want some grand irony? The GM xfer case calls for ATF, and some people go "off the reservation" and use engine oil. Yet, there are some Harley riders that swear by the use of ATF, rather than the spec'd lube (essentially engine oil), in their primary cases. Talk about your "grass is greener on the other side" approach! Both cases are essentially link-plate chain driven boxes!
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Just an after thought here...since its a NP transfercase, spec'd for ATF; why not use a MTF in the 5w30 range instead of motor oil?
I've ran both Royal Purple SynchroMax and currently Redline MTL in my dodge transfercase (an NP 271?) with seemingly good success...I have over 150k on RP and only about 5k on RL. I have about 225k on the truck.
I've ran both Royal Purple SynchroMax and currently Redline MTL in my dodge transfercase (an NP 271?) with seemingly good success...I have over 150k on RP and only about 5k on RL. I have about 225k on the truck.
Dave: I don't know why a 5W30 wouldn't work in a t-case, but I don't know why it would have any particular advantage. I've used THF (tractor Transmission Hydraulic FLuid) in t-cases. It's a littler heavier than most ATFs (9-10+cSt). I liked those because they often have more and better antiwear add-packs that ATF. I make no claims as to the efficacy of it, but it worked for me and at least one other farmer I know. Some of the ad packs in the are quite robust! SOme are into the 30 engine grade viscosity
Deeter: I have Used synchro-mesh type fluid, like Synchomax, in t-cases over the years with good results. The aforementioned Range Rover gearboxes responded well t0 BG's Synchro Shift (whatever formulation they used in the early 1990s). It didn't fry in 15-30K miles like ATF. I have Synchromax in both my trucks. Nothing to note in either case. I did try to see if it dropped t-case temp but the results were inconclusive. Didn't see any drop of note.
Deeter: I have Used synchro-mesh type fluid, like Synchomax, in t-cases over the years with good results. The aforementioned Range Rover gearboxes responded well t0 BG's Synchro Shift (whatever formulation they used in the early 1990s). It didn't fry in 15-30K miles like ATF. I have Synchromax in both my trucks. Nothing to note in either case. I did try to see if it dropped t-case temp but the results were inconclusive. Didn't see any drop of note.
Jim I have used THF in the Ford service van I don't remember what year it had a 460 and an auto and it worked great . I have always wondered about THF in manual trannies that recommended ATF . The original MTF.
I would wager most of the fluid loss is likely caused by normal seepage over a long period of time. Most people totally ignore their transfer case until it fails. If 5 years go by without anyone topping off the fluid, you could easily loose a quart just from slight seepage of seals.
If the level is checked once or twice a year and topped off as necessary, failure would be prevented. (not counting the pump rub issue)
If the level is checked once or twice a year and topped off as necessary, failure would be prevented. (not counting the pump rub issue)
dnewton3
Staff member
When I spoke with the product development folks in NY at NV, some of the original people who worked on that project were still there.
ATF was chosen because it is the "best compromise" of all the attributes they sought. Now, I understand that the words "best compromise" can either have postive or negative connotations in some people's minds. Since I've worked at Ford for 16 years, and now work in a different industry (quality engineer) I can say that EVERYTHING YOU BUY is a "compromise" between the goals of strength, longevity, cost, safety, environment and operational issues, etc. So, for NV to tell me that the ATF was the "best compromise" is not a bad thing.
One thing they noted was that ATF has a much better affect on the t-case at cold temps. This is especially important for people like me that have the manually shifted 261 case in my one-ton. The ATF allows the shifter to glide much easier than thicker fluids. If you review the vis of typical DEX III type ATF and 5w-30, the vis difference really isn't that great at full op temps such as 100 deg c. But look at the cold temp properties! The 5w-30 gets much thicker on a more pronounced slope than does ATF. Shifting a t-case with engine oil in it in winter at 12 deg F would be a bear with engine oil, but it is easily managed with the ATF. Further, the t-case does get hot when used heavily in the summer; that's true. But the t-case also struggles to get up to any decent temp when it's winter temps. It's not uncommon for me to only drive perhaps 10 miles in winter in 4x4; the xfer case has no hope of getting "up to temp" when it's below freezing during such short trips. Here again, the "thinner" nature of the ATF actually lubes the link plates and pins "better" than 5w-30 will when it's cold.
I had not thought of UTF (universal tractor fluid) as a possible option; it certainly might work well.
But overall, it was really easy for me to get two quarts of Mobil 1 ATF, and be done with it. Keeps my in warranty (or, did at the time; expired now) and provides the "best compromise" of performance and protection at ALL temps for a wide variety of conditions. Since I had to drain the t-case at 10k miles to do the "pump rub" elimination kit, it was a good excuse to fill back up with the synthetic ATF. Done and Done.
I'm not saying 5w-30 is automatically detrimental. I just get a bit peeved when people profess that 5w-30 is somehow "best" over the alternatives or the OEM spec'd fluid. One guy (Weinberg) suggested the use of 5w-30; that's it; the rest of the industry does not support his conclusion. And his conclusion was borne with no factual basis or true engineering study; he swagged it. That does NOT make it a bad decision; that makes it an uneducated guess.
Like I said earlier, this topic really boils down to two seperate things:
1) low (or no) fluid levels can cause mechanical damgage (no big suprise). You must do preventative maintenance to avert these conditions. Having some decent amount of any lube is better than having almost no fluid level of the proper lube. Neglect is the owner's fault; not the lube's fault.
2) "pump rub" cannot be averted with any lube choice. This mechanical condition is ONLY pre-empted by the intervention of an physical barrier from the aftermarket. It will happen at some point; there is no indication as to "when" it might happen.
ATF was chosen because it is the "best compromise" of all the attributes they sought. Now, I understand that the words "best compromise" can either have postive or negative connotations in some people's minds. Since I've worked at Ford for 16 years, and now work in a different industry (quality engineer) I can say that EVERYTHING YOU BUY is a "compromise" between the goals of strength, longevity, cost, safety, environment and operational issues, etc. So, for NV to tell me that the ATF was the "best compromise" is not a bad thing.
One thing they noted was that ATF has a much better affect on the t-case at cold temps. This is especially important for people like me that have the manually shifted 261 case in my one-ton. The ATF allows the shifter to glide much easier than thicker fluids. If you review the vis of typical DEX III type ATF and 5w-30, the vis difference really isn't that great at full op temps such as 100 deg c. But look at the cold temp properties! The 5w-30 gets much thicker on a more pronounced slope than does ATF. Shifting a t-case with engine oil in it in winter at 12 deg F would be a bear with engine oil, but it is easily managed with the ATF. Further, the t-case does get hot when used heavily in the summer; that's true. But the t-case also struggles to get up to any decent temp when it's winter temps. It's not uncommon for me to only drive perhaps 10 miles in winter in 4x4; the xfer case has no hope of getting "up to temp" when it's below freezing during such short trips. Here again, the "thinner" nature of the ATF actually lubes the link plates and pins "better" than 5w-30 will when it's cold.
I had not thought of UTF (universal tractor fluid) as a possible option; it certainly might work well.
But overall, it was really easy for me to get two quarts of Mobil 1 ATF, and be done with it. Keeps my in warranty (or, did at the time; expired now) and provides the "best compromise" of performance and protection at ALL temps for a wide variety of conditions. Since I had to drain the t-case at 10k miles to do the "pump rub" elimination kit, it was a good excuse to fill back up with the synthetic ATF. Done and Done.
I'm not saying 5w-30 is automatically detrimental. I just get a bit peeved when people profess that 5w-30 is somehow "best" over the alternatives or the OEM spec'd fluid. One guy (Weinberg) suggested the use of 5w-30; that's it; the rest of the industry does not support his conclusion. And his conclusion was borne with no factual basis or true engineering study; he swagged it. That does NOT make it a bad decision; that makes it an uneducated guess.
Like I said earlier, this topic really boils down to two seperate things:
1) low (or no) fluid levels can cause mechanical damgage (no big suprise). You must do preventative maintenance to avert these conditions. Having some decent amount of any lube is better than having almost no fluid level of the proper lube. Neglect is the owner's fault; not the lube's fault.
2) "pump rub" cannot be averted with any lube choice. This mechanical condition is ONLY pre-empted by the intervention of an physical barrier from the aftermarket. It will happen at some point; there is no indication as to "when" it might happen.
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Originally Posted By: dnewton3
I had not thought of UTF (universal tractor fluid) as a possible option; it certainly might work well.
The guy that gave me the idea is a big farmer locally and has used it in his '05 Duramax Chevy for about 90K miles now. Used hard, I might add. He also used it in his previous Chevy chain drive t-case for it's entire life.. and he still uses that truck. Some of THF (I prefer that term over UTF) are multi-vis 10W20, which solves the winter issue.
FYI, I prefer THF because "UTF" used to also be for the old universal tractor oils that you could use in the engine, the final drive, or whatever. UTF is commonly used now in the context we have discussed, but the acronym makes my brain do flips for some reason. I'm also quite irrationally pedantic on some things...
If you get into the trans oil VOA section, you'll find I posted some VOAs and UOAs of THF that may be of interest. Their formulation and designed purpose seems to me to be better suited to t-case and maybe to manual trans operation than ATF. The viscosity is certainly close enough. I feel pretty confident about efficacy in a t-case. Less so in a trans, mostly from not having studied it in any detail. I can also say that, like many other oils, they are slowly getting the Z&P out of tractor oils. The Z&P levels are much lower in the modern THFs that some of the older "recipes" Mola or Bruce381 shared with me.
It occurs to me that Honda Z1 might make a good t-case formula, as it has more gear type additives than most ATFs
FInally, my spec sheet for the NVG 261 (copied from a NVG document) shows a capacity of 5.1 qts. It says QUARTS, not pints. You likely have a factory manual, or a least the OM. What is the capacity? You were talking about 3 quarts and such.
I had not thought of UTF (universal tractor fluid) as a possible option; it certainly might work well.
The guy that gave me the idea is a big farmer locally and has used it in his '05 Duramax Chevy for about 90K miles now. Used hard, I might add. He also used it in his previous Chevy chain drive t-case for it's entire life.. and he still uses that truck. Some of THF (I prefer that term over UTF) are multi-vis 10W20, which solves the winter issue.
FYI, I prefer THF because "UTF" used to also be for the old universal tractor oils that you could use in the engine, the final drive, or whatever. UTF is commonly used now in the context we have discussed, but the acronym makes my brain do flips for some reason. I'm also quite irrationally pedantic on some things...
If you get into the trans oil VOA section, you'll find I posted some VOAs and UOAs of THF that may be of interest. Their formulation and designed purpose seems to me to be better suited to t-case and maybe to manual trans operation than ATF. The viscosity is certainly close enough. I feel pretty confident about efficacy in a t-case. Less so in a trans, mostly from not having studied it in any detail. I can also say that, like many other oils, they are slowly getting the Z&P out of tractor oils. The Z&P levels are much lower in the modern THFs that some of the older "recipes" Mola or Bruce381 shared with me.
It occurs to me that Honda Z1 might make a good t-case formula, as it has more gear type additives than most ATFs
FInally, my spec sheet for the NVG 261 (copied from a NVG document) shows a capacity of 5.1 qts. It says QUARTS, not pints. You likely have a factory manual, or a least the OM. What is the capacity? You were talking about 3 quarts and such.
Originally Posted By: Jim Allen
D
Deeter: I have Synchromax in both my trucks. Nothing to note in either case. I did try to see if it dropped t-case temp but the results were inconclusive. Didn't see any drop of note.
I have found that temperature on manual boxes tends to be whatever the hottest operating part is attached to them...in my truck, the NV5600's temp is almost solely based on the engine temps (it will reach 180*F sitting at idle); and I would assume that the tcase being attached to the NV5600 would cause it to have a minimum temperature because of direct connection.
As I stated in another thread, I think the small "captured" amounts of fluid we have in manual boxes (boxes that have no significant cooling mechanism) lends very little to operating temperatures.
D
Deeter: I have Synchromax in both my trucks. Nothing to note in either case. I did try to see if it dropped t-case temp but the results were inconclusive. Didn't see any drop of note.
I have found that temperature on manual boxes tends to be whatever the hottest operating part is attached to them...in my truck, the NV5600's temp is almost solely based on the engine temps (it will reach 180*F sitting at idle); and I would assume that the tcase being attached to the NV5600 would cause it to have a minimum temperature because of direct connection.
As I stated in another thread, I think the small "captured" amounts of fluid we have in manual boxes (boxes that have no significant cooling mechanism) lends very little to operating temperatures.
Originally Posted By: cronk
I would wager most of the fluid loss is likely caused by normal seepage over a long period of time. Most people totally ignore their transfer case until it fails. If 5 years go by without anyone topping off the fluid, you could easily loose a quart just from slight seepage of seals.
If the level is checked once or twice a year and topped off as necessary, failure would be prevented. (not counting the pump rub issue)
Depending on the operating temperature, I can see where a fluid would volatilize, and result in a lost volume...the reason there is a NOACK volatility test.
I would hazard a guess that all fluids are subject to volatilization.
On a side note...when I drained my tcase, the fluid did not appear to be ATF (it was definitely NOT ATF+4 which is the specified fluid)...it was thicker than ATF and PURPLE. I believe my in house GM guy called it Grape Juice?
I would wager most of the fluid loss is likely caused by normal seepage over a long period of time. Most people totally ignore their transfer case until it fails. If 5 years go by without anyone topping off the fluid, you could easily loose a quart just from slight seepage of seals.
If the level is checked once or twice a year and topped off as necessary, failure would be prevented. (not counting the pump rub issue)
Depending on the operating temperature, I can see where a fluid would volatilize, and result in a lost volume...the reason there is a NOACK volatility test.
I would hazard a guess that all fluids are subject to volatilization.
On a side note...when I drained my tcase, the fluid did not appear to be ATF (it was definitely NOT ATF+4 which is the specified fluid)...it was thicker than ATF and PURPLE. I believe my in house GM guy called it Grape Juice?
Originally Posted By: dnewton3
W
I'm not saying 5w-30 is automatically detrimental. I just get a bit peeved when people profess that 5w-30 is somehow "best" over the alternatives or the OEM spec'd fluid.
We see this in the Dodge transmission folks as well...they like to use 15w40 and 5w40 in the Getrag 360 and the NV4500, and synthetic 5w30 (typically Amsoil) in the NV5600.
I was under the impression that motor oils were not "designed" to protect gears like a true gear oil?
W
I'm not saying 5w-30 is automatically detrimental. I just get a bit peeved when people profess that 5w-30 is somehow "best" over the alternatives or the OEM spec'd fluid.
We see this in the Dodge transmission folks as well...they like to use 15w40 and 5w40 in the Getrag 360 and the NV4500, and synthetic 5w30 (typically Amsoil) in the NV5600.
I was under the impression that motor oils were not "designed" to protect gears like a true gear oil?
dnewton3
Staff member
Originally Posted By: deeter16317
On a side note...when I drained my tcase, the fluid did not appear to be ATF (it was definitely NOT ATF+4 which is the specified fluid)...it was thicker than ATF and PURPLE. I believe my in house GM guy called it Grape Juice?
Oooooooo - that's a bit scary. "Grape Juice" is the colloquial term for the available from fluid from GM over the parts counter; looks and smells like grapes - hence the term. The GM fluid spec is #9986115; it's 75w-90 GL-5 rated hypoid gear oil made for GM by Texaco.
On a side note...when I drained my tcase, the fluid did not appear to be ATF (it was definitely NOT ATF+4 which is the specified fluid)...it was thicker than ATF and PURPLE. I believe my in house GM guy called it Grape Juice?
Oooooooo - that's a bit scary. "Grape Juice" is the colloquial term for the available from fluid from GM over the parts counter; looks and smells like grapes - hence the term. The GM fluid spec is #9986115; it's 75w-90 GL-5 rated hypoid gear oil made for GM by Texaco.
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Originally Posted By: dnewton3
Oooooooo - that's a bit scary. "Grape Juice" is the colloquial term for the 75w-90 GL-5 rated hypoid gear oil available from GM; looks and smells like grapes - hence the term.
My in-house GM guy just said that what it sounded like...whatever it was, it was the OE factory fill. This had no odd odor, just didn't look like ATF+4.
Oooooooo - that's a bit scary. "Grape Juice" is the colloquial term for the 75w-90 GL-5 rated hypoid gear oil available from GM; looks and smells like grapes - hence the term.
My in-house GM guy just said that what it sounded like...whatever it was, it was the OE factory fill. This had no odd odor, just didn't look like ATF+4.
dnewton3
Staff member
Originally Posted By: Jim Allen
FInally, my spec sheet for the NVG 261 (copied from a NVG document) shows a capacity of 5.1 qts. It says QUARTS, not pints. You likely have a factory manual, or a least the OM. What is the capacity? You were talking about 3 quarts and such.
There is no way I can fathom 5.1 qrts getting in there. I suspect a misprint? I put in 2 qrts via the fill hole, and the fluid level sits just below that hole. 2 qrts is the "manual" spec and the commonly accepted volume in the GM truck world.
The suggested "over-fill" method is a total of 3 qrts, and has to be added via the speed-sensor hole on the very top of the case. 3 qrts really makes for a full case; that's 50% overfilled. Even this "overfill" technique cannot support 5.1 qrts; most of the volume over 3 qrts would end up overflowing the case and end up everywhere.
FInally, my spec sheet for the NVG 261 (copied from a NVG document) shows a capacity of 5.1 qts. It says QUARTS, not pints. You likely have a factory manual, or a least the OM. What is the capacity? You were talking about 3 quarts and such.
There is no way I can fathom 5.1 qrts getting in there. I suspect a misprint? I put in 2 qrts via the fill hole, and the fluid level sits just below that hole. 2 qrts is the "manual" spec and the commonly accepted volume in the GM truck world.
The suggested "over-fill" method is a total of 3 qrts, and has to be added via the speed-sensor hole on the very top of the case. 3 qrts really makes for a full case; that's 50% overfilled. Even this "overfill" technique cannot support 5.1 qrts; most of the volume over 3 qrts would end up overflowing the case and end up everywhere.
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Originally Posted By: dnewton3
Originally Posted By: Jim Allen
FInally, my spec sheet for the NVG 261 (copied from a NVG document) shows a capacity of 5.1 qts. It says QUARTS, not pints. You likely have a factory manual, or a least the OM. What is the capacity? You were talking about 3 quarts and such.
There is no way I can fathom 5.1 qrts getting in there. I suspect a misprint? I put in 2 qrts via the fill hole, and the fluid level sits just below that hole. 2 qrts is the "manual" spec and the commonly accepted volume in the GM truck world.
The suggested "over-fill" method is a total of 3 qrts, and has to be added via the speed-sensor hole on the very top of the case. 3 qrts really makes for a full case; that's 50% overfilled. Even this "overfill" technique cannot support 5.1 qrts; most of the volume over 3 qrts would end up overflowing the case and end up everywhere.
I can get just a little over 2 quarts in my NP271...I agree, 5 quarts would be extremely overfilled.
Originally Posted By: Jim Allen
FInally, my spec sheet for the NVG 261 (copied from a NVG document) shows a capacity of 5.1 qts. It says QUARTS, not pints. You likely have a factory manual, or a least the OM. What is the capacity? You were talking about 3 quarts and such.
There is no way I can fathom 5.1 qrts getting in there. I suspect a misprint? I put in 2 qrts via the fill hole, and the fluid level sits just below that hole. 2 qrts is the "manual" spec and the commonly accepted volume in the GM truck world.
The suggested "over-fill" method is a total of 3 qrts, and has to be added via the speed-sensor hole on the very top of the case. 3 qrts really makes for a full case; that's 50% overfilled. Even this "overfill" technique cannot support 5.1 qrts; most of the volume over 3 qrts would end up overflowing the case and end up everywhere.
I can get just a little over 2 quarts in my NP271...I agree, 5 quarts would be extremely overfilled.
dnewton3
Staff member
Originally Posted By: deeter16317
Originally Posted By: dnewton3
Oooooooo - that's a bit scary. "Grape Juice" is the colloquial term for the 75w-90 GL-5 rated hypoid gear oil available from GM; looks and smells like grapes - hence the term.
My in-house GM guy just said that what it sounded like...whatever it was, it was the OE factory fill. This had no odd odor, just didn't look like ATF+4.
For a while GM was using their "AutoTrak" fluid in the that t-case; it was a dark blue. Perhaps a bit of color shift and it now looks purple? It had little if any odor; not at all like the Grape Juice. The AutoTrak fluid was specific for the auto-shift t-cases. I'll make the distinction that "auto-shift" and electronic shift are not the same thing. The GM HD trucks never had an "auto" shifting transfer case. They have a case that is shifted via electronic solenoids (the 263) only when the driver commands the shift via the button pushed. This is not the same as the 'autotrack' feature, which sensed wheel slip and shifted without driver interaction. No one really knows for sure why GM used that fluid for a while. But they only did it about one year in the HD trucks.
There are/were actually several variations of the NV cases used in the GM trucks.
The 1500 (half ton) got the auto-track version; light duty.
The 2500 (3/4 ton) got the 261 (manual shift) and 263 (eletronic shift) cases (called "heavy duty")
The 3500 (1 ton) got even beefier 261 and 263 cases, called the 261 Super Duty and 263 Extreme Duty, respectivly. These one-ton units got upsized input/output shafts even larger than the 3/4 ton trucks.
Originally Posted By: dnewton3
Oooooooo - that's a bit scary. "Grape Juice" is the colloquial term for the 75w-90 GL-5 rated hypoid gear oil available from GM; looks and smells like grapes - hence the term.
My in-house GM guy just said that what it sounded like...whatever it was, it was the OE factory fill. This had no odd odor, just didn't look like ATF+4.
For a while GM was using their "AutoTrak" fluid in the that t-case; it was a dark blue. Perhaps a bit of color shift and it now looks purple? It had little if any odor; not at all like the Grape Juice. The AutoTrak fluid was specific for the auto-shift t-cases. I'll make the distinction that "auto-shift" and electronic shift are not the same thing. The GM HD trucks never had an "auto" shifting transfer case. They have a case that is shifted via electronic solenoids (the 263) only when the driver commands the shift via the button pushed. This is not the same as the 'autotrack' feature, which sensed wheel slip and shifted without driver interaction. No one really knows for sure why GM used that fluid for a while. But they only did it about one year in the HD trucks.
There are/were actually several variations of the NV cases used in the GM trucks.
The 1500 (half ton) got the auto-track version; light duty.
The 2500 (3/4 ton) got the 261 (manual shift) and 263 (eletronic shift) cases (called "heavy duty")
The 3500 (1 ton) got even beefier 261 and 263 cases, called the 261 Super Duty and 263 Extreme Duty, respectivly. These one-ton units got upsized input/output shafts even larger than the 3/4 ton trucks.
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Originally Posted By: dnewton3
Originally Posted By: deeter16317
Originally Posted By: dnewton3
Oooooooo - that's a bit scary. "Grape Juice" is the colloquial term for the 75w-90 GL-5 rated hypoid gear oil available from GM; looks and smells like grapes - hence the term.
My in-house GM guy just said that what it sounded like...whatever it was, it was the OE factory fill. This had no odd odor, just didn't look like ATF+4.
For a while GM was using their "AutoTrak" fluid in the that t-case; it was a dark blue. Perhaps a bit of color shift and it now looks purple? It had little if any odor; not at all like the Grape Juice. The AutoTrak fluid was specific for the auto-shift t-cases. I'll make the distinction that "auto-shift" and electronic shift are not the same thing. The GM HD trucks never had an "auto" shifting transfer case. They have a case that is shifted via electronic solenoids (the 263) only when the driver commands the shift via the button pushed. This is not the same as the 'autotrack' feature, which sensed wheel slip and shifted without driver interaction. No one really knows for sure why GM used that fluid for a while. But they only did it about one year in the HD trucks.
There are/were actually several variations of the NV cases used in the GM trucks.
The 1500 (half ton) got the auto-track version; light duty.
The 2500 (3/4 ton) got the 261 (manual shift) and 263 (eletronic shift) cases (called "heavy duty")
The 3500 (1 ton) got even beefier 261 and 263 cases, called the 261 Super Duty and 263 Extreme Duty, respectivly. These one-ton units got upsized input/output shafts even larger than the 3/4 ton trucks.
I'm talking an NP271 (manual shift) used in the Dodge 2500/3500 series...like I said, it definitely wasn't ATF+4!
Originally Posted By: deeter16317
Originally Posted By: dnewton3
Oooooooo - that's a bit scary. "Grape Juice" is the colloquial term for the 75w-90 GL-5 rated hypoid gear oil available from GM; looks and smells like grapes - hence the term.
My in-house GM guy just said that what it sounded like...whatever it was, it was the OE factory fill. This had no odd odor, just didn't look like ATF+4.
For a while GM was using their "AutoTrak" fluid in the that t-case; it was a dark blue. Perhaps a bit of color shift and it now looks purple? It had little if any odor; not at all like the Grape Juice. The AutoTrak fluid was specific for the auto-shift t-cases. I'll make the distinction that "auto-shift" and electronic shift are not the same thing. The GM HD trucks never had an "auto" shifting transfer case. They have a case that is shifted via electronic solenoids (the 263) only when the driver commands the shift via the button pushed. This is not the same as the 'autotrack' feature, which sensed wheel slip and shifted without driver interaction. No one really knows for sure why GM used that fluid for a while. But they only did it about one year in the HD trucks.
There are/were actually several variations of the NV cases used in the GM trucks.
The 1500 (half ton) got the auto-track version; light duty.
The 2500 (3/4 ton) got the 261 (manual shift) and 263 (eletronic shift) cases (called "heavy duty")
The 3500 (1 ton) got even beefier 261 and 263 cases, called the 261 Super Duty and 263 Extreme Duty, respectivly. These one-ton units got upsized input/output shafts even larger than the 3/4 ton trucks.
I'm talking an NP271 (manual shift) used in the Dodge 2500/3500 series...like I said, it definitely wasn't ATF+4!
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