I am going to need to change the rear end oil in my 2004 Duelley, 410 rear end Anti-spin Differential. What oil do I need to use, how much, and do I get the oil from the dealer or is there a better source.

 

Any synthetic 75w140 gear oil will work just fine. I'm not sure if you have the helical LSD or not, but if you do, no need for additive. When you're in there spray everything down with carb cleaner and clean the bottom of the pumpkin.

 

Factory spec is for synthetic GL-5 75W-90 front and rear. Factory spec on the SECOND generation trucks was for 75W-140 (rear only) for towing applications. Both of these weights are available from most parts retailers, I use Mobil One synthetic. On your 2004 do not add friction modifier. You would be hard pressed to find a source that is worse (read that as more expensive) than the dealer. The gasket on the pumpkin made to be reused.

Some folks that tow heavy are using 75W-140 in the rear on third gen trucks. If you search you will find some posts on the subject.

I use 75W-90 front and rear and it takes about 7-1/2 quarts for both.

 

I have been searching for the TSB that states that the gear oil for the rear diff for towing can be changed to 75w-140, with no luck. Can anyone point me to this particuler TSB?

 

I think it was this one. http://dodgeram.info/tsb/2004/03-001-04A.htm

MikeyB

 

Katfish most of us just use 75w90 as the manual recommends. I use GL-5 spec Mobil 1 75w90 gear lube, which is available at almost every auto parts store I've been to.

 

I just bought another case of 75w90... and I tow 10K#.
Hopefully that's OK? I'll revisit it next time I order gear oil.
I'm thinking that changing it regularly and running an oversized pumkin are helping a lot for long term wear.

 

I decided to play it safe and went with 75w-140. Mainly for our hot Texas summers.

MikeyB

 

redline 75w-90 for me. i dont tow anything. redline is about as good as it gets
buy it from summit racing quick ship and they dont screw your order up