Aam 11.5 diff. Oil

[EMurillo]

one more question fellows i am changing my engine oil, trans oil, transfer case oil, and both my axles this weekend and before i do it i want to make sure i have all the right stuff. any way the question is i went to buy the axle oil and the sales guy recommended the 75-140 synthetic he said that would be a good choice since i tow frequently, so i thought i check with the pros. you guys. so what do you think?Oo.



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2004. 5 ctd, slt short bed, 4 x 4, 325. 600 ho, bf goodrich tires, rancho 9000, gray, gauges, boost, trans, egt's, f/er, 30/fer, ope exhaust, .

 

[Jim W]

Most guys that are towing heavy and long distance use the 75W-140 gear lub in their trucks.

 

[daverobb]

75-140 is recommended for HD use. Care should be taken in extremely cold climates to change it out before winter. I know several guys around here who are running 75-90 all year. Which ever you go with, make sure to use a full synthetic. You do not need LSD additive.

 

[MA2LA]

just an odd question, would an additive help a LSD that isn't holding like it used to. Mine just dosen't act as solid as it used to a and can make driving on slippery roads unpredictable at times.

 

[Barry]

I did something stupid. I ran 100K before changing the diff fluid. I lived in Texas for 35 years and now have moved to Florida. Having said that, that is the reason I always ran 75/140.



However, the real point I want to make is... ... ..... start looking at the differentials of the trucks with the American Axles. If they have any miles on them at all, the banjo housing is a burnt rusty brown while the axle tubes are still nice and black.



Putting as much power through the diffs as we(especially those of us that haul and tow alot) creates a lot of heat. Especially in high ambient temps. 3 quarts of fluid is just not going to keep that axle cool. I should have installed a Mag-Hytec long ago.



It is the next thing on my truck to-do list!

 

[THoltz]

Yes, use 75 W 140 full synthetic (not a synthetic blend). I use Mobil 1.

 

[SMorton]

Amsoil Severe Gear 75/140, and have had no troubles here in the Mtns of Colorado during cold weather. Factory fill was synthetic as well. Amsoil also offers a 75/110 severe gear lube. If you check their website, they have a 28 page gear lube study that really gets involved in the properties of gear/axle lubrication, and comparison studies to most of the available gear lubes on the market.

 

[Bug Out]

I use Amsoil Severe gear 75-90 syn and have never recorded temps over 200 or so. I tow a 40' toy hauler.

 

[Midnite]

just an odd question, would an additive help a LSD that isn't holding like it used to. Mine just dosen't act as solid as it used to a and can make driving on slippery roads unpredictable at times.

Limited slip additive is used to make the LS unit slip more, not less. If you added more additive to your gear lube your limited slip would be even worse than it is now.



Sounds like you need to get it rebuilt.



Mike

 

[daverobb]

LSD additive in an AAM axle will do nothing except waist your money. The LSD additive is intended for clutch type LSDs. The AAMs are gear type LSDs.

 

[TTimmons]

I use Amsoil Severe Gear 75w-90 in my diffs as well, no problems here. I tow a 26ft travel trailer pretty much every other weekend in spring, summer and fall.

 

[steved]

The AAMs are gear type LSDs.

... with clutches. While not specifically called "clutches," they are termed "shoes. " Further, while they don't specifically call for LSD additive, it has been used in cases where the owner complains of a shudder.

I have been running 85w140 royal purple for over four years and 120k now (with an extra capacity aluminum cover). Oil looks as good as the day I installed it, four years ago.

 

[rluft]

I run amsoil 75-110 w/ LSD additive. I always try the gear oil only during a change but end up adding the additive to stop the chatter.

 

[Shadrach]

I was told by my dealer the rear diff required special oil - Dodge p/n 5102232AA? Frt diff uses 75/90 T case ATF+4 Shadrach

 

[steved]

I was tol by my dealer the rear diff required special oil - Dodge p/n 5102232AA? Frt diff uses 75/90 T case ATF+4 Shadrach

Owner's manual indicates 75w90 synthetic in both the front and rear... there was a Dodge memo/letter/recommendation (for the 2500/3500) for using 75w140 if you tow heavy and often.

 

[daverobb]

I was tol by my dealer the rear diff required special oil - Dodge p/n 5102232AA? Frt diff uses 75/90 T case ATF+4 Shadrach

Both front and rear diffs require 75/90 synthetic or if you do heavy (at or beyond the tow rating) towing, use 75/140. No Limited Slip additive is required. I can't remember part #s but I would think that the part # you quoted is for Mopar synthetic 75/90. Any good synthetic gear lube will work.

 

[macdaddy]

When I drained the Mopar 75-140 from mine after 60K it looked like the day I poured it in.



The stuff is remarkable.



Mac

 

[DaveHess]

I have a slight howl from my rear diff when I am off the throttle and rolling down a grade. I switched from a factory fill to RedLine Synthetic 80w-140 and the howl is gone. I run RedLine Shock-Proof Heavy in my drag car after tearing up a ring and pinion with Amsoil inside. I know basically to each his own but RedLine has never let me down in 16 seasons of racing. Amsoil lasted about 10 laps. BTW, the next change-out for me will see RedLine 75W-140. I did not realize their 80W-140 was designed for commercial applications. Now older and wiser!

 

[Barry]

Very interesting Uncle Dave... ... ... ... ... ... ... ... .....

 

[steved]

I have a slight howl from my rear diff when I am off the throttle and rolling down a grade. I switched from a factory fill to RedLine Synthetic 80w-140 and the howl is gone. I run RedLine Shock-Proof Heavy in my drag car after tearing up a ring and pinion with Amsoil inside. I know basically to each his own but RedLine has never let me down in 16 seasons of racing. Amsoil lasted about 10 laps. BTW, the next change-out for me will see RedLine 75W-140. I did not realize their 80W-140 was designed for commercial applications. Now older and wiser!

Mine had a pretty good whine with 75w90, but it went away with 85w140 and an aluminum cover... so it could just be the oil is attenuating the sound.