GL4 conventional gear oil for manual trans?

T

TheButaneBandit

Joined
Apr 30, 2026
Messages
10
I have a 'franken-truck'. it seems like I might have a 2002 Dodge 3500 2wd cab, possibly a third gen dodge front 4wd axle, and other drama. Not sure if my frame is cab-n-chassis or regular. No idea.



I assume I have an NV4500 transmissionmission. Who knows, it could be from a Chevy or anything



Are NV4500s supposed to take GL4, GL5, dual G4/GL5, or perhaps something else? Allegedly, GL4, since the NV4500 has brass synchros.



I have only ever put fluid in automatic transmissionmissions, and only through using the dipstick tube, I've never messed with fluid in a standard transmissionmission. I know nowadays in the 21st century a lot of gear oil and maybe some ATF jugs are designed to be squeezed. I'm trying to be cheap especially since this isnt a fresh rebuild or new unit, so I wont be looking for fancy squeeze jugs. I think the third gear synchro is already worn out. I could be draining the transmission again sooner than later, especially if I mess something up. I went with Triax. Shown below.



I know it's the wrong viscosity, and it's synthetic not conventional. But it was cheap. And I can return it. I also ordered a pump



https://a.co/d/04vjJIS3



https://a.co/d/07esAqwJ





I know the transmission leaked a lot since I parked it, but I may check the diffs too, not sure if I can mix fluids in there. I dont think diffs are picky about GL4 vs GL5, and I assume none of the diffs need friction modifier. TC I know nothing about. I think it says New Process something or other. I assume the TC takes atf.



I just said the transmission leaked; I think the NV4500 might need a new right side PTO cover gasket, I will try to do that too. Not sure if thats a job for oil RTV or if they sell a paper gasket. If the cover is coming off, I can look inside and try to pull out any pieces that might be inside.



Thank you!!!
 
Wash off the grime on the transmissions and the differentials and do a web search on the numbers seen on the driveline components.

You have already made your decision for the transmission fluid so I was curious why you even posted?
 
MolaKule said:
Wash off the grime on the transmissions and the differentials and do a web search on the numbers seen on the driveline components.

You have already made your decision for the transmission fluid so I was curious why you even posted?
Click to expand...
I'm not trying to be curt or fresh, but by your logic, if someone,  after buying a fluid, was to discover that the fluid they bought might incredibly damage their vehicle, they would be crazy to heed said new knowledge or advice, and they should just put the fluid they already have into the machine instead of buying something more appropriate, period, end of story. I bought this fluid when I thought there was an emergency and I had to drive the truck a couple hundred miles, and the truck was low on fluid, and I did my best. I figured the wrong but still-kind-to-bronze fluid was better than GL5 and/or no fluid at all. There has been new developments since then, and now I know I no longer have to do that drive, and I have more time to try to do more research. This vehicle is not my daily driver, I have more than one, thank god.

FB_IMG_1777585272835.webp


FB_IMG_1777585275741.webp


FB_IMG_1777585279979.webp
 
Good info on the NV4500 lube requirements here.

Torque King

Scroll down to the Tech notes.

I owned a 96 Dodge Ram Cummins with the NV4500. I used both Redline MT90 and Amsoil 75w90 GL4 until I sold it 20 years later with 175k miles on it. I never had any shifting issues.
 
use GL5 if you want to replace your synchros soon.

Good luck finding GL4 locally.....Valvoline synchromesh is widely available, or 10w30 motor oil
 
Do NOT use GL5 in a manual transmission unless the manufacturer specifically states it is ok.

The extreme pressure additives will attack the yellow metals and wear them out prematurely.

Do use GL5 in differential gears. The hypoid ring and pinion require extreme pressure additives.
 
@TheButaneBandit

Okay, we didn't know the full story until you posted later.

Below is a link and if you think the transmission requires a certain grade, there is a list of 75W90 or 75W85 choices to choose from:

MolaKule

Thread 'Updated List of MTFs May 1st, 2026'

Updated List of Manual Transmission Fluids Updated May 30th, 2025

NOTE: This list is only a “summary” list of MTFs available in the MTF Lubricant Market and only available in US auto parts stores and US Import outlets. It is not an endorsement nor a critique of any one fluid, nor is it implied that any one fluid will cure problems in MTs that have design problems or those that have excessive wear. Viscosities listed are at 100C and rounded up.

A.These MTL fluids are closest to a Kinematic Viscosity of 6.X cSt@100C (About the same viscosity as Dexron VI ATF) LV MTF's:

1. HPL Manual...
  • Like
  • Helpful
  • Love

SInce you weren't sure what transmission might be in it that's the reason I suggested trying to find the numbers on it and do a web search.
 
MolaKule said:
@TheButaneBandit

Okay, we didn't know the full story until you posted later.

Below is a link and if you think the transmission requires a certain grade, there is a list of 75W90 or 75W85 choices to choose from:

MolaKule

Thread 'Updated List of MTFs May 1st, 2026'

Updated List of Manual Transmission Fluids Updated May 30th, 2025

NOTE: This list is only a “summary” list of MTFs available in the MTF Lubricant Market and only available in US auto parts stores and US Import outlets. It is not an endorsement nor a critique of any one fluid, nor is it implied that any one fluid will cure problems in MTs that have design problems or those that have excessive wear. Viscosities listed are at 100C and rounded up.

A.These MTL fluids are closest to a Kinematic Viscosity of 6.X cSt@100C (About the same viscosity as Dexron VI ATF) LV MTF's:

1. HPL Manual...
  • Like
  • Helpful
  • Love

SInce you weren't sure what transmission might be in it that's the reason I suggested trying to find the numbers on it and do a web search.
Click to expand...
I'm not expecting you to research for me, but is that little round tag with red paint likely what, I should be using, or should there be a rectangular data plate somewhere? I might be retarded and those old photos I attached are the TC not the transmission. I need to slow down and look closer, apologies, crazy day. Thank you all very much

Oh yup I'm a bozo, it says New Process, if it was the transmission it would likely say new venture, wouldn't it. Although my dad has a new Process 4 speed manual in his truck, I think. I guess I'm still not sure. I graduate undergraduate tomorrow and I'm sending work emails, so I probably shouldn't have made this post, but I will research and try to take photos of the transmission, apologies
 
Big E said:
Do NOT use GL5 in a manual transmission unless the manufacturer specifically states it is ok.

The extreme pressure additives will attack the yellow metals and wear them out prematurely.

Do use GL5 in differential gears. The hypoid ring and pinion require extreme pressure additives.
Click to expand...
I thought if anything in life was simple it's that with the possible exception of friction modifier, differentials have way less fluid drama.... I thought there was likely never yellow metal in differentials. I have a bunch of this fluid https://a.co/d/08MXsrMv . In 2021, Facebook people told me I could use this fluid in my NV4500 transmission. It's a GL5 fluid. Luckily I never ended up using it. I was under the impression I could check my differentials too and use this GL5 fluid if they were low and/or i wanred to change the fluid. I assume both differentials are open, but I have no idea.

My dad said 'I have no way of knowing for certain, but I would guess and speculate that GL5 is a superior fluid, with the major exception that it's unkind to copper and copper-based alloys'

I thought diffs were not picky about fluid. It's funny how few people actually know anything about this, thank god for ya'll. I cannot imagine that mechanics across the country are inserting the correct fluids into final drives and transmissions and transfer cases
 
The pics you posted are the transfer case not the transmission.

It appears to be a New Process 242 DHD. The lube spec is ATF +4
 
Also curious why you think you have a 3rd gen Dodge front differential. If the center axle disconnect (CAD) module is present, located on the passenger side of the axle, you most definitely have a Dana 60.
 
Bearing Sea said:
Also curious why you think you have a 3rd gen Dodge front differential. If the center axle disconnect (CAD) module is present, located on the passenger side of the axle, you most definitely have a Dana 60.
Click to expand...
I have no idea man. Some random guy told me he thought it was third gen

FB_IMG_1777598251313.webp


FB_IMG_1777598234573.webp
 
Big E said:
The pics you posted are the transfer case not the transmission.

It appears to be a New Process 242 DHD. The lube spec is ATF +4
Click to expand...
I figured any vehicle this new with an aluminum transfer case case/shell has chain inside, and therefore must take ATF. What is +4???
 
The tag is a t-case. That's an NP241DHD. I have gotten medieval on the 241 Dodge, taking three t-cases to make one good one and custom machining the planetary input to take the later, double row bearing. That said, none of that helps you with an NV4500

I recently rebuilt an NV4500 following vids from TK and Andrew at Long Range Gear. Andrew says the ONLY fluid where he'll stand behind his warranty is Redline MT85. It's readily available at O'Reilly, although they may have to order it (overnight from their hub). I'd be skeptical of ebay. Redline fluids are all over ebay but I don't trust them.

Watch vids of Andrew at Long Range Gear. He rebuilds the NV4500 from memory very casually because he's obviously done so many.
 
D60 said:
The tag is a t-case. That's an NP241DHD. I have gotten medieval on the 241 Dodge, taking three t-cases to make one good one and custom machining the planetary input to take the later, double row bearing. That said, none of that helps you with an NV4500

I recently rebuilt an NV4500 following vids from TK and Andrew at Long Range Gear. Andrew says the ONLY fluid where he'll stand behind his warranty is Redline MT85. It's readily available at O'Reilly, although they may have to order it (overnight from their hub). I'd be skeptical of ebay. Redline fluids are all over ebay but I don't trust them.

Watch vids of Andrew at Long Range Gear. He rebuilds the NV4500 from memory very casually because he's obviously done so many.
Click to expand...
If I had just dropped thousands on a DIY and/or paid rebuild, maybe id be more apt to blow ninety or a hundred dollars on 1 gallon

Your first paragraph is over my head. Do I recall that before crappy cheesy chain transfer cases debuted, they had planetary gear transfer cases? You're correct, im missing how this is particularly relevant. But learning is good
 
TheButaneBandit said:
What is +4???
Click to expand...
ATF+4 is Chrysler specified ATF.

The ATF +4 fluid that was to become the MS-9604 (and the MS-9602 through MS-9224) specification began about 1989. Improved oxidation, shear stability, anti-wear, FM stability, and torque converter shudder were the main goals.

Chrysler partnered with the Texaco Oil Company and the Lubrizol Corporation during the development.

Texaco had developed a Group III XHVI Base Oil having excellent oxidative resistance and good low-temperature fluidity. Texaco developed Group III base oil approached the performance of a synthetic fluid but at a lower cost.

Lubrizol was able to tailor an additive system that was synergistic with the base oil. During the course of the project, Lubrizol also developed a new viscosity index improver to provide the needed viscosity stability.

The original ATF +4 formulation recipe requires only a Group III base oil with specific characteristics and the Lubrizol additive package. No PAOs or esters were specified.

Blenders who wanted to replicate the ATF +4 for sale had to use a specific Group III base oil of specified properties with the Lubrizol additive package as outlined in the Lubrizol recipe.

The Chrysler internal part number for ATF+ 4 in quarts is 68218057AC
 
  • Like
Reactions: D60
TheButaneBandit said:
If I had just dropped thousands on a DIY and/or paid rebuild, maybe id be more apt to blow ninety or a hundred dollars on 1 gallon

Your first paragraph is over my head. Do I recall that before crappy cheesy chain transfer cases debuted, they had planetary gear transfer cases? You're correct, im missing how this is particularly relevant. But learning is good
Click to expand...
~$24 to $28 per qt is competitive retail on the MT85. Other approved fluids are no cheaper.

The NV4500 in particular is VERY picky about fluid due to the unique frictions. There are horror stories of people getting a rebuild, refilling with basic MTF or Synchromesh and having terrible shifting after the very first drive home from the shop.

Oddly you can skimp on the NV3500 or NV5600 (not that I'd recommend it) but the 4500 is unique.

Take care of that transfer case, too. The 241Ds (DHD = Dodge Heavy Duty so you should have a PTO while the DLDs did not) are RARE. Really rare these days.
 
D60 said:
~$24 to $28 per qt is competitive retail on the MT85. Other approved fluids are no cheaper.

The NV4500 in particular is VERY picky about fluid due to the unique frictions. There are horror stories of people getting a rebuild, refilling with basic MTF or Synchromesh and having terrible shifting after the very first drive home from the shop.

Oddly you can skimp on the NV3500 or NV5600 (not that I'd recommend it) but the 4500 is unique.

Take care of that transfer case, too. The 241Ds (DHD = Dodge Heavy Duty so you should have a PTO while the DLDs did not) are RARE. Really rare these days.
Click to expand...
Is Lucas that pricy? Valvoline and Ultra 1 Plus must be cheaper than that. I bought Triax, which is like ~$40 USD for a gallon on Amazon.

I thought nobody has sold Synchromesh since Obama was President?

When people rebuild a 4500 do they sometimes eliminate the picky fickle need for some special fluid?

I guess I need to make sure my 241D (assuming you are certain it is a 241D) is full of atf? Is it picky about what kind of ATF? I'm unsure if it has drain and fill plugs... I recall Dodge Dakotas might not have drain and fill plugs on their TCs... Do all TCs usually have plugs, or do mechanics have to split the case? IDK what all this PTO talk is. Is it really the TC, not the transmission itself that has PTO(s)? I thought the side covers on the transmission itself were called "PTO covers"....? The right side cover on my transmission is leaking I'm pretty sure and I thought google calls it the PTO cover...

As you can see I'm inept and know very little althought that probably makes me qualified to work at most shops nowadays, sadly. Not any riskier working on my own stuff than paying somebody to work on it. And I'm out here asking questions, which is more than we can say for a lot of the overconfident technicians nowadays. Still, I'm just a bozo
 
You must log in or register to reply here.

Similar threads

A
GL4 vs Dual certified for manual trans (Toyota GR86)
2
Replies
24
Views
817
ceecbtg
C
Rear diff oil turns dark grey
Replies
8
Views
778
Corniit
H
oil for 1990 Toyota corolla all-trac wagon (ae95) transmission/transfer case
Replies
9
Views
1K
MolaKule
S
75W85 GL4 vs 75W85 GL4/GL5 vs 75w90 GL4
2
Replies
24
Views
10K
slimypi
L
Gear oil for '73 Dodge D200 manual
Replies
6
Views
275
dnewton3
Back
Top Bottom