Just got done changing out a leaking rear axle seal in my '03 2500 HD and just finished putting everything back together. All seems and feels good but I'm wondering about the rear differential oil. I know that I lost a bit from the leak and then a bit more from pulling the axles, bearings and seals and now I want to re-fill the diff. From what I've found in research, it should be 75 W90 gear oil added through the plug in the rear of the pumpking cover to bring the level to just below the plug opening. Is it that simple? Also, is it worthwhile to pull the pumpkin cover to drain and clean and then refill?

Thanks in advance.

 

75-90 GL-5 is what you need. If you have enough miles since the last service might as well change it. Simple to do and gaskets are reusable.

 

There is a fill line etched into the cover below the hole fill hole but I just fill until it runs out of the hole.
There was also a TSB out that if you towed heavy or worked your truck hard to run 75w140.

 

I tow an 34' 5er in the summer and run high miles year round (although other than the 5er, no real towing). Think I qualify for 75w140?

 

I wish somebody would show me this TSB I hear about every once in a while. The only one I have ever seen addresses Ram 1500 (half-ton) trucks. Not our AAM Ram 2500/3500 axles.

I know some guys run 140 weight and apparently it's ok....I don't hear about problems. But Dodge, as far as I know........says run 75W90 GL-5 Rated gear oil ONLY!!! Can somebody show me something official that says otherwise?

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As far as I know........unless your driving a half ton Dodge Ram....you don't.

Our axles call for 75w90 synthetic GL-5 rated gear oil. Heavier is not better.

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I asked Dodge back in 2007 about the 75/140 and was told that the TSB was only for the half ton 1500 pickups and not the 2500 or 3500 trucks with 11.5 axles. As its been posted many times Dodge still calls for us to use 75/90 synthetic GL-5 rated gear oil.

 

What is the capacity of the rear axle on an 06? Lookin to change it this weekend and want to make sure I get enough oil

 

Just curious here, as I have known folks to run 80W90 non-synthetic GL-5 rated high capacity gear oil (including myself) for YEARS without a single solitary issue, such as gear wear or oil shear/breakdown, what would be the problem in doing so if changed at normal intervals?

It, like the difference in price between dino and synthetic engine oils, is night and day, yet I have also known folks to get hundreds of thousands of miles out of dino oil changed out at normal intervals in their engines.

Sorry, I just don't see paying more than twice the price for fluids when I haven't seen any evidence showing that what I am using is doing harm to my vehicle and likewise with my friends.

I am open to any and all opinions and suggestions, as always though!

 

I can't see any problems with that...I for one, have run regular in mine before. It just gets too darn cold where I live to run 80W90. I would love to run Chevron ESI 80W90 though if I could get away with it during winter....

 

I'm really old-school about diff lube. I had a 97 D80 that ran blazing hot and didn't cool down or have good uoas til I used 85w140 and a Mag cover didn't help but the Dana Mag cover had the fill hole higher so the wheel brgs would get plenty of oil, which I liked. Does anyone know how high the fill hole is in the Mag covers for the AAMs? I run 5 qts of 85w140 in my 03 and the temp is the same, no seal leaking and the uoa is very good. Craig

 

C Shomer, here's a pic of my Mag-Hytec cover that I just put on not to long ago. Upper right of the cover about the one o'clock position is the dipstick/fill hole. Took 8 quarts to fill.

 

I hear ya. I didn't even take into consideration the cold climates. I too, would stay away from any lubes that can't hack the weather conditions.

On a separate note, I just changed my differential fluids again last night. I put 20K on this 80W90 rather than the recommended 15K that I had been doing and I have to be honest, I think that next time, I will extend it out to 30K.

It still looked and felt just about exactly like it did the day I put it in. VERY slick and honey colored.

 

Chris, is the oil level higher with the Mag cover than with the stock cover? Thanks, Craig