Diff Change Intervals

[AWise]

What is your recommended change interval for the diff oil (front and rear)? I know this is a loaded question and I will get many different responses, but I would like to know how often you guys change it. I tow occasionally with most use being mixed city/highway, 15k mi per year. I dont tow anything heavy, maybe a car every now and then. I am coming up on 50k and I am thinking about putting on a new diff cover and changing out the oil. The oil brand isnt really important, I know there are many good ones. I am just curious about the interval.

 

[HBarlow]

The owner's manual specifies a lube change at 15k mile intervals.

I installed a Mag-Hytec cover when my '06 had 300 miles on the odometer and changed the differential lube (2wd) at 50k mile intervals. I sold the truck at 230k miles and everything was working as well as new including the limited slip feature.

Some have posted that the frequent lube change interval is necessary because of the design of the limited slip feature of the AAM rear end assembly used in Gen III trucks. I cannot agree or disagree with their position. I saw no evidence that I had damaged mine by following my own service interval.

I don't recommend a 50k interval, that is up to each owner. But I followed it on an '06 truck and am currently following the same service interval on my '08. It has 43k on the odometer and I haven't changed the differential lube yet.

 

[WCounts]

What is your recommended change interval for the diff oil (front and rear)? I know this is a loaded question and I will get many different responses, but I would like to know how often you guys change it. I tow occasionally with most use being mixed city/highway, 15k mi per year. I dont tow anything heavy, maybe a car every now and then. I am coming up on 50k and I am thinking about putting on a new diff cover and changing out the oil. The oil brand isnt really important, I know there are many good ones. I am just curious about the interval.

If you have the AAM TracRite use inexpensive GL-5 gear oil and change it often. I would not go over 15K.

Billy

 

[macdaddy]

Overkill!!!!!!!!!!!

I changed mine at 15K..... And it was nasty.



15K installed Mag High Tec dumped it again at 50K it looked like the day I poured it in (Mopar 75/140). At $20. 00 a quart and 8 quarts to boot ill let it go 60K.



As for the front its been in there since 15K. It is like the day I poured it in. It will go 100k no worries. 4WD doesnt really get used much.



The truck has 75K currently.



Mac

 

[WCounts]

The front doesn't get metal in it and stays clean so it doesn't need to be changed very often. If the truck doesn't go arround many tight turns or do much spinning I can see where some folks could go longer between changes.

Billy

 

[CumminsPower98]

Maybe I have no business talking in here since I have a '98 with open Dana 80 but I have personally run 100K a few times with about 45% towing on Amsoil 75w140. The oil comes out looking really good too after all that and no diff. problems to speak of. I'm not recommending anyone follow what I do but its got 402k miles now.



What I will say that would pertain to any differential is that the first lube change is the most critical to get the break-in stuff out of there.

 

[WCounts]

Maybe I have no business talking in here since I have a '98 with open Dana 80 but I have personally run 100K a few times with about 45% towing on Amsoil 75w140. The oil comes out looking really good too after all that and no diff. problems to speak of. I'm not recommending anyone follow what I do but its got 402k miles now.



What I will say that would pertain to any differential is that the first lube change is the most critical to get the break-in stuff out of there.

The open rear ends don't get clutch material or metal in the oil after initial breakin so they can go much longer.

Billy

 

[DE Jeeper]

Third gens ls doesn't have clutches so you don't have to worry about contamination. There have been some good threads on this subject with many responses if you do a search. I change at 50-75k on my truck with stock diff covers and I pull heavy trailers regularly. With 170k on the truck the diff oil always comes out gold and clean. I use the cheapest snyth on the shelf at Pep Boys.



Aaron

 

[steved]

AAMs do indeed have clutches, they are called shoes.



While they work differently from a tracloc or powerloc, they still have clutch material in them.



Look at any of the third gen FSMs...

 

[DE Jeeper]

AAMs do indeed have clutches, they are called shoes.



While they work differently from a tracloc or powerloc, they still have clutch material in them.



Look at any of the third gen FSMs...

Not saying your wrong because I have neither seen the FSM or taken one apart, but from the pics I have seen and the description of what it is I assumed it was all gear. see link with description "FACTORY HELICAL GEAR STYLE POSI / LIMITED SLIP, 30 SPLINE AXLES"

POSI & LIMITED SLIP - CHRY 11. 50 - AAM 40041224

Now you know what happens when you "assume", but with no need for friction additive and not needing to be rebuilt I was thinking there were no clutches.



Aaron

 

[AWise]

Thanks for the info guys. I think I will start using a 25k change interval. I am going to order a Mag-Hytec rear cover and change out the fluid in front and rear.

 

[AWise]

Just changed out the diff lube with Amsoil 70w-90 and slapped on a Mag-Hytec. I was concerned about the oil since schedule B says 15k change interval and i hadn't changed it out yet (46k), although i only tow occasionally and not very heavy. Oil looked to be in good shape, there was just a very light gray film on the old cover and in the bottom of the housing. The magnet had the normal bit of metal goo on it but no chunks. MH cover looks nice, hope it clears the spare tire...



Again, thanks for all your help guys!