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Its your diff.
Why not compromise and run a 75w110!
Why not compromise and run a 75w110!
75w-140
- Thread starter Fasttimez
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To everyone that has posted in this thread I really do THANK YOU. If I rubbed anyone the wrong way I apologize, it wasn't my intention to do that at all. The reason for this thread is I actually spoke to someone that formulates gear oils, he said they actually spec'd out an oil years ago for Ford when they were having problems with their rears. He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140. Maybe I should have given that tidbit of info first but I didn't wanna open a bigger fan of worms.
Originally Posted By: Fasttimez
He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140.
Allow me to further elaborate on my previous workings above,where it says that in relations to desired gear oil KV@40C (from 213 cSt to 161 cSt) at varying road speeds of 40 - 70 mph :
KV@40C of following gear oils, in increasing order of viscosity are :-
a) Mobil 1 LS 75W-90; Synthetic; GL5; 106 cSt --- Inadequate
b) Mobilube® HD 80W-90; Dino; GL5; 136 cSt ------ Barely adequate
c) Mobil 1 LS 75W-140; Synthetic; GL5; 179 cSt ---Quite adequate
d) Mobilube® HD 85W-140; Dino; GL5; 377 cSt ------More than adequate.Caveat:ambient not below -10 C
e) Mobilube GX SAE 140; Dino; GL4; 447 cSt--------Over-the-top adequate.Ambient not below 0 C
Ford's final selection of synthetic 75W-140 at approximate KV@40C of 179 cSt makes perfect sense in this market where it's ambient does get below -10 C.
In my tropical climate of minimum 24 C year round, 85W-140 of KV@40C of 377 cSt would provide wear protection in a wider range of road speeds well below 40 mph.
Note: In a way, the selection of Synpower 75W-90 of KV@40C of 100 cSt above, would likely cap power output per differential at about 50-60 hp .
JMO.
He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140.
Allow me to further elaborate on my previous workings above,where it says that in relations to desired gear oil KV@40C (from 213 cSt to 161 cSt) at varying road speeds of 40 - 70 mph :
KV@40C of following gear oils, in increasing order of viscosity are :-
a) Mobil 1 LS 75W-90; Synthetic; GL5; 106 cSt --- Inadequate
b) Mobilube® HD 80W-90; Dino; GL5; 136 cSt ------ Barely adequate
c) Mobil 1 LS 75W-140; Synthetic; GL5; 179 cSt ---Quite adequate
d) Mobilube® HD 85W-140; Dino; GL5; 377 cSt ------More than adequate.Caveat:ambient not below -10 C
e) Mobilube GX SAE 140; Dino; GL4; 447 cSt--------Over-the-top adequate.Ambient not below 0 C
Ford's final selection of synthetic 75W-140 at approximate KV@40C of 179 cSt makes perfect sense in this market where it's ambient does get below -10 C.
In my tropical climate of minimum 24 C year round, 85W-140 of KV@40C of 377 cSt would provide wear protection in a wider range of road speeds well below 40 mph.
Note: In a way, the selection of Synpower 75W-90 of KV@40C of 100 cSt above, would likely cap power output per differential at about 50-60 hp .
JMO.
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My 97 and 99 F150, both with the 8.8 rear end (4.6l V8 trucks) used 75w140 from the factory. Its been in use for a long time. Yes, they originally went to 75w90 on '04 F150's, but quickly went back to 75w140 where it remains to this day.
Its your truck, use what you want. If it were mine, I wouldn't have overthought it and just put in what was required and been done with it.
Its your truck, use what you want. If it were mine, I wouldn't have overthought it and just put in what was required and been done with it.
Originally Posted By: zeng
Originally Posted By: Fasttimez
He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140.
Allow me to further elaborate on my previous workings above,where it says that in relations to desired gear oil KV@40C (from 213 cSt to 161 cSt) at varying road speeds of 40 - 70 mph :
KV@40C of following gear oils, in increasing order of viscosity are :-
a) Mobil 1 LS 75W-90; Synthetic; GL5; 106 cSt --- Inadequate
b) Mobilube® HD 80W-90; Dino; GL5; 136 cSt ------ Barely adequate
c) Mobil 1 LS 75W-140; Synthetic; GL5; 179 cSt ---Quite adequate
d) Mobilube® HD 85W-140; Dino; GL5; 377 cSt ------More than adequate.Caveat:ambient not below -10 C
e) Mobilube GX SAE 140; Dino; GL4; 447 cSt--------Over-the-top adequate.Ambient not below 0 C
Ford's final selection of synthetic 75W-140 at approximate KV@40C of 179 cSt makes perfect sense in this market where it's ambient does get below -10 C.
In my tropical climate of minimum 24 C year round, 85W-140 of KV@40C of 377 cSt would provide wear protection in a wider range of road speeds well below 40 mph.
Note: In a way, the selection of Synpower 75W-90 of KV@40C of 100 cSt above, would likely cap power output per differential at about 50-60 hp .
JMO.
If according to your findings 75w-90 & 80w-90 gear oils are inadequate or barely adequate, then why are they so widely used by GM, Ram, Jeep, the US Military & more for the gear oil grade of choice ? So according to your above findings, EVERYONE should be using 75w-140 gear oil ?
Originally Posted By: Fasttimez
He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140.
Allow me to further elaborate on my previous workings above,where it says that in relations to desired gear oil KV@40C (from 213 cSt to 161 cSt) at varying road speeds of 40 - 70 mph :
KV@40C of following gear oils, in increasing order of viscosity are :-
a) Mobil 1 LS 75W-90; Synthetic; GL5; 106 cSt --- Inadequate
b) Mobilube® HD 80W-90; Dino; GL5; 136 cSt ------ Barely adequate
c) Mobil 1 LS 75W-140; Synthetic; GL5; 179 cSt ---Quite adequate
d) Mobilube® HD 85W-140; Dino; GL5; 377 cSt ------More than adequate.Caveat:ambient not below -10 C
e) Mobilube GX SAE 140; Dino; GL4; 447 cSt--------Over-the-top adequate.Ambient not below 0 C
Ford's final selection of synthetic 75W-140 at approximate KV@40C of 179 cSt makes perfect sense in this market where it's ambient does get below -10 C.
In my tropical climate of minimum 24 C year round, 85W-140 of KV@40C of 377 cSt would provide wear protection in a wider range of road speeds well below 40 mph.
Note: In a way, the selection of Synpower 75W-90 of KV@40C of 100 cSt above, would likely cap power output per differential at about 50-60 hp .
JMO.
If according to your findings 75w-90 & 80w-90 gear oils are inadequate or barely adequate, then why are they so widely used by GM, Ram, Jeep, the US Military & more for the gear oil grade of choice ? So according to your above findings, EVERYONE should be using 75w-140 gear oil ?
Originally Posted By: MNgopher
My 97 and 99 F150, both with the 8.8 rear end (4.6l V8 trucks) used 75w140 from the factory. Its been in use for a long time. Yes, they originally went to 75w90 on '04 F150's, but quickly went back to 75w140 where it remains to this day.
Its your truck, use what you want. If it were mine, I wouldn't have overthought it and just put in what was required and been done with it.
Because nobody on BITOG overthinks any selection of lubricant for their vehicle....lol
My 97 and 99 F150, both with the 8.8 rear end (4.6l V8 trucks) used 75w140 from the factory. Its been in use for a long time. Yes, they originally went to 75w90 on '04 F150's, but quickly went back to 75w140 where it remains to this day.
Its your truck, use what you want. If it were mine, I wouldn't have overthought it and just put in what was required and been done with it.
Because nobody on BITOG overthinks any selection of lubricant for their vehicle....lol
Originally Posted By: Fasttimez
Originally Posted By: zeng
Originally Posted By: Fasttimez
He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140.
Allow me to further elaborate on my previous workings above,where it says that in relations to desired gear oil KV@40C (from 213 cSt to 161 cSt) at varying road speeds of 40 - 70 mph :
KV@40C of following gear oils, in increasing order of viscosity are :-
a) Mobil 1 LS 75W-90; Synthetic; GL5; 106 cSt --- Inadequate
b) Mobilube® HD 80W-90; Dino; GL5; 136 cSt ------ Barely adequate
c) Mobil 1 LS 75W-140; Synthetic; GL5; 179 cSt ---Quite adequate
d) Mobilube® HD 85W-140; Dino; GL5; 377 cSt ------More than adequate.Caveat:ambient not below -10 C
e) Mobilube GX SAE 140; Dino; GL4; 447 cSt--------Over-the-top adequate.Ambient not below 0 C
Ford's final selection of synthetic 75W-140 at approximate KV@40C of 179 cSt makes perfect sense in this market where it's ambient does get below -10 C.
In my tropical climate of minimum 24 C year round, 85W-140 of KV@40C of 377 cSt would provide wear protection in a wider range of road speeds well below 40 mph.
Note: In a way, the selection of Synpower 75W-90 of KV@40C of 100 cSt above, would likely cap power output per differential at about 50-60 hp .
JMO.
If according to your findings 75w-90 & 80w-90 gear oils are inadequate or barely adequate, then why are they so widely used by GM, Ram, Jeep, the US Military & more for the gear oil grade of choice ? So according to your above findings, EVERYONE should be using 75w-140 gear oil ?
Who provided the data for a) tire size 275/55R20 , b) bevel ring PCD of 9.75 inches and c) road speed of 70 MPH ??
Good nite .....
Originally Posted By: zeng
Originally Posted By: Fasttimez
He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140.
Allow me to further elaborate on my previous workings above,where it says that in relations to desired gear oil KV@40C (from 213 cSt to 161 cSt) at varying road speeds of 40 - 70 mph :
KV@40C of following gear oils, in increasing order of viscosity are :-
a) Mobil 1 LS 75W-90; Synthetic; GL5; 106 cSt --- Inadequate
b) Mobilube® HD 80W-90; Dino; GL5; 136 cSt ------ Barely adequate
c) Mobil 1 LS 75W-140; Synthetic; GL5; 179 cSt ---Quite adequate
d) Mobilube® HD 85W-140; Dino; GL5; 377 cSt ------More than adequate.Caveat:ambient not below -10 C
e) Mobilube GX SAE 140; Dino; GL4; 447 cSt--------Over-the-top adequate.Ambient not below 0 C
Ford's final selection of synthetic 75W-140 at approximate KV@40C of 179 cSt makes perfect sense in this market where it's ambient does get below -10 C.
In my tropical climate of minimum 24 C year round, 85W-140 of KV@40C of 377 cSt would provide wear protection in a wider range of road speeds well below 40 mph.
Note: In a way, the selection of Synpower 75W-90 of KV@40C of 100 cSt above, would likely cap power output per differential at about 50-60 hp .
JMO.
If according to your findings 75w-90 & 80w-90 gear oils are inadequate or barely adequate, then why are they so widely used by GM, Ram, Jeep, the US Military & more for the gear oil grade of choice ? So according to your above findings, EVERYONE should be using 75w-140 gear oil ?
Who provided the data for a) tire size 275/55R20 , b) bevel ring PCD of 9.75 inches and c) road speed of 70 MPH ??
Good nite .....
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Originally Posted By: zeng
Originally Posted By: Fasttimez
Originally Posted By: zeng
Originally Posted By: Fasttimez
He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140.
Allow me to further elaborate on my previous workings above,where it says that in relations to desired gear oil KV@40C (from 213 cSt to 161 cSt) at varying road speeds of 40 - 70 mph :
KV@40C of following gear oils, in increasing order of viscosity are :-
a) Mobil 1 LS 75W-90; Synthetic; GL5; 106 cSt --- Inadequate
b) Mobilube® HD 80W-90; Dino; GL5; 136 cSt ------ Barely adequate
c) Mobil 1 LS 75W-140; Synthetic; GL5; 179 cSt ---Quite adequate
d) Mobilube® HD 85W-140; Dino; GL5; 377 cSt ------More than adequate.Caveat:ambient not below -10 C
e) Mobilube GX SAE 140; Dino; GL4; 447 cSt--------Over-the-top adequate.Ambient not below 0 C
Ford's final selection of synthetic 75W-140 at approximate KV@40C of 179 cSt makes perfect sense in this market where it's ambient does get below -10 C.
In my tropical climate of minimum 24 C year round, 85W-140 of KV@40C of 377 cSt would provide wear protection in a wider range of road speeds well below 40 mph.
Note: In a way, the selection of Synpower 75W-90 of KV@40C of 100 cSt above, would likely cap power output per differential at about 50-60 hp .
JMO.
If according to your findings 75w-90 & 80w-90 gear oils are inadequate or barely adequate, then why are they so widely used by GM, Ram, Jeep, the US Military & more for the gear oil grade of choice ? So according to your above findings, EVERYONE should be using 75w-140 gear oil ?
Who provided the data for a) tire size 275/55R20 , b) bevel ring PCD of 9.75 inches and c) road speed of 70 MPH ??
Good nite .....
I think you missed my point, your "graph" can be applied to pretty much any vehicle with 20" wheels & similar size ring gear. So please explain then why they don't spec 75w-140 gear oil for those vehicles.
Originally Posted By: Fasttimez
Originally Posted By: zeng
Originally Posted By: Fasttimez
He said they formulated a 80w-90 full synthetic fluid that did fine, but Ford backed away from it instead keeping the 75w-140.
Allow me to further elaborate on my previous workings above,where it says that in relations to desired gear oil KV@40C (from 213 cSt to 161 cSt) at varying road speeds of 40 - 70 mph :
KV@40C of following gear oils, in increasing order of viscosity are :-
a) Mobil 1 LS 75W-90; Synthetic; GL5; 106 cSt --- Inadequate
b) Mobilube® HD 80W-90; Dino; GL5; 136 cSt ------ Barely adequate
c) Mobil 1 LS 75W-140; Synthetic; GL5; 179 cSt ---Quite adequate
d) Mobilube® HD 85W-140; Dino; GL5; 377 cSt ------More than adequate.Caveat:ambient not below -10 C
e) Mobilube GX SAE 140; Dino; GL4; 447 cSt--------Over-the-top adequate.Ambient not below 0 C
Ford's final selection of synthetic 75W-140 at approximate KV@40C of 179 cSt makes perfect sense in this market where it's ambient does get below -10 C.
In my tropical climate of minimum 24 C year round, 85W-140 of KV@40C of 377 cSt would provide wear protection in a wider range of road speeds well below 40 mph.
Note: In a way, the selection of Synpower 75W-90 of KV@40C of 100 cSt above, would likely cap power output per differential at about 50-60 hp .
JMO.
If according to your findings 75w-90 & 80w-90 gear oils are inadequate or barely adequate, then why are they so widely used by GM, Ram, Jeep, the US Military & more for the gear oil grade of choice ? So according to your above findings, EVERYONE should be using 75w-140 gear oil ?
Who provided the data for a) tire size 275/55R20 , b) bevel ring PCD of 9.75 inches and c) road speed of 70 MPH ??
Good nite .....
I think you missed my point, your "graph" can be applied to pretty much any vehicle with 20" wheels & similar size ring gear. So please explain then why they don't spec 75w-140 gear oil for those vehicles.
check out the widman gear oil viscosity calculator.
I get for my car a minimum of iso 150 which translates to a 90 weight gear oil
I get for my car a minimum of iso 150 which translates to a 90 weight gear oil
Here's the actual TSB from Ford BTW.
Technical Service Bulletin TSB 05-23-3 changes the lube for rear differentials to 75W140 GL5 full synthetic.
1997-2005 Expedition, F-150
NOTE WHEN SERVICING THE REAR AXLE ON ANY 2002-2004 F-150, EXPEDITION, NAVIGATOR, EXPLORER OR MOUNTAINEER BUILT BEFORE 3/30/2004, IF FLUID REPLACEMENT IS REQUIRED, REPLACE THE ORIGINAL FUEL EFFICIENT HIGH PERFORMANCE (FEHP) SAE 75W-90 REAR AXLE LUBRICANT WITH SAE 75W-140 HIGH PERFORMANCE SYNTHETIC REAR AXLE LUBRICANT. WHEN THE FLUID TYPE IS CHANGED, REPLACE THE CURRENT "FEHP" METAL TAG WITH A NEW "75W-140" TAG (F3TZ-4121-AA). IN ADDITION, REMOVE OR BLOCK-OUT THE FEHP REFERENCE ON THE MULTI-COLORED LABEL LOCATED ON THE RIGHT SIDE AXLE TUBE. IF THE AXLE IS A LIMITED-SLIP MODEL, USE XL3 ADDITIVE FRICTION MODIFIER IN THE QUANTITY RECOMMENDED BY THE WORKSHOP MANUAL.
Technical Service Bulletin TSB 05-23-3 changes the lube for rear differentials to 75W140 GL5 full synthetic.
1997-2005 Expedition, F-150
NOTE WHEN SERVICING THE REAR AXLE ON ANY 2002-2004 F-150, EXPEDITION, NAVIGATOR, EXPLORER OR MOUNTAINEER BUILT BEFORE 3/30/2004, IF FLUID REPLACEMENT IS REQUIRED, REPLACE THE ORIGINAL FUEL EFFICIENT HIGH PERFORMANCE (FEHP) SAE 75W-90 REAR AXLE LUBRICANT WITH SAE 75W-140 HIGH PERFORMANCE SYNTHETIC REAR AXLE LUBRICANT. WHEN THE FLUID TYPE IS CHANGED, REPLACE THE CURRENT "FEHP" METAL TAG WITH A NEW "75W-140" TAG (F3TZ-4121-AA). IN ADDITION, REMOVE OR BLOCK-OUT THE FEHP REFERENCE ON THE MULTI-COLORED LABEL LOCATED ON THE RIGHT SIDE AXLE TUBE. IF THE AXLE IS A LIMITED-SLIP MODEL, USE XL3 ADDITIVE FRICTION MODIFIER IN THE QUANTITY RECOMMENDED BY THE WORKSHOP MANUAL.
Originally Posted By: Jetronic
check out the widman gear oil viscosity calculator.
I get for my car a minimum of iso 150 which translates to a 90 weight gear oil
Thank you, doing the calculation my truck DOES NOT need 75w-140 gear oil. It barely specs above 90w, it's right on the line of 90w & 110w.
check out the widman gear oil viscosity calculator.
I get for my car a minimum of iso 150 which translates to a 90 weight gear oil
Thank you, doing the calculation my truck DOES NOT need 75w-140 gear oil. It barely specs above 90w, it's right on the line of 90w & 110w.
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at low rpms and lower gears the spec goes up though, to iso 460 for my car... ie towing and offroading
Originally Posted By: Jetronic
at low rpms and lower gears the spec goes up though, to iso 460 for my car... ie towing and offroading
Yes, I went to the website & played around with the calculator to see what my high & low numbers would be.
at low rpms and lower gears the spec goes up though, to iso 460 for my car... ie towing and offroading
Yes, I went to the website & played around with the calculator to see what my high & low numbers would be.
Found out another tidbit of info also.
"SAE split the 90 grade range in 2001. Bottom half of the 'old' 90 stayed as 90, but the top half of the range became 110. The 110 is still rare and hard to find so Ford probably went straight to 140 to save the hassle of trying to find a 110 grade oil. The 140 split the same way; top half is now called 190 grade.
The main reason was for gear whine concerns, not durability issues. People were complaining of gear whine, which had nothing to do with durability of the axle. Ford opted to put the overly thick 140 grade to quiet the axle noise, & that's the only reason it's used vs 75w-90, they had so many gear whine warranty claims they just went overboard & put 75w-140 in everything to make it easy on themselves."
"SAE split the 90 grade range in 2001. Bottom half of the 'old' 90 stayed as 90, but the top half of the range became 110. The 110 is still rare and hard to find so Ford probably went straight to 140 to save the hassle of trying to find a 110 grade oil. The 140 split the same way; top half is now called 190 grade.
The main reason was for gear whine concerns, not durability issues. People were complaining of gear whine, which had nothing to do with durability of the axle. Ford opted to put the overly thick 140 grade to quiet the axle noise, & that's the only reason it's used vs 75w-90, they had so many gear whine warranty claims they just went overboard & put 75w-140 in everything to make it easy on themselves."
I'd use a 75w110 in your case, if you're on that according to the calculator.. or a thick 75w90 in old money
It makes no sense why the SAE would want to make more grades of oil, the old specs for the 90w & 140w were obviously working fine. Just people out engineering themselves I guess. They tear the 90w grade in half, making a 110w oil class that nobody save Amsoil makes a quality lube for. Just idiots doing idiotic stuff for the sake of doing it I guess.
The 90 and 140 grades where space out too much, there's quite a bit of difference between a a thin and a thick 90 as it was before.
the 190 grqde is very narrow and doesn't make much sense to me...
the 190 grqde is very narrow and doesn't make much sense to me...
The closest comparison I can make between my 9.75" axle is the Toyota Tundra. This is essentially a rendition of the Ford 9" rear in its build. It can have up to a 4.30 gear ratio.....it only calls for 75w-90 gear oil. The Toyota puts more power to the rear than my truck, yet Ford specs 75w-140 for mine. Just a good comparison I thought.
Coincidence or not,
my brand new in 2004 Dodge RAM 1500 4.7l 2WD was specced for 75W-140 in the "9-1/4" rear axle w/3.55 gears
as I live in a rather cool climate (Montreal) and never towed or hauled anything I figured a quality synthetic 75W-90 would
suffice and help with the lousy gas mileage and cold weather flow.
Diff. got a fresh fill of RedLine every 3 years.
After 10 years-120K miles, the rear axle started whinning badly at speed / at operating temp. as the pinion bearing went south.
By this point I tried switching to a mineral 80W-140 to delay repairs but it was still as noisy.
My new 2014 base model F-150 XL 3.7V6 specs 75W-140 and you can bet I won't 'experiment' with using a thinner gear lube in it.
my brand new in 2004 Dodge RAM 1500 4.7l 2WD was specced for 75W-140 in the "9-1/4" rear axle w/3.55 gears
as I live in a rather cool climate (Montreal) and never towed or hauled anything I figured a quality synthetic 75W-90 would
suffice and help with the lousy gas mileage and cold weather flow.
Diff. got a fresh fill of RedLine every 3 years.
After 10 years-120K miles, the rear axle started whinning badly at speed / at operating temp. as the pinion bearing went south.
By this point I tried switching to a mineral 80W-140 to delay repairs but it was still as noisy.
My new 2014 base model F-150 XL 3.7V6 specs 75W-140 and you can bet I won't 'experiment' with using a thinner gear lube in it.
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