diffs on a ram 2500

[racer12306]

My dad has a 2005 Ram 2500 with the cummins 600. The truck has a huge 11.5" AAM (i have heard it was the same as the gm diff but with larger axle tubes). Dodge says to change the diff (front and rear)oil every 15000 miles, but some dealers say to change it at 15000 and then every 30000 after that. The dealer charges $22/qt and redline has a similar fluid for about $7/qt and amsoil has their severe gear fluid for about $9/qt. My dad has already decided on the redline for the price. Combined the diffs take 7 qts.

What do you think for recomended intervals? Right now the truck does not tow it is a daily driver. But if needed it will tow.

 

[Hootbro]

Unless the dealer has a TSB to waiver from the manual, I would stick to what the manual says. Come warranty time, the person at the dealer could be gone or changing his tune.

Hootbro

 

[Jim Allen]

If you don't tow, a 15,000 mile OCI is overkill IMO. Were it me, I'd go with the second recommendation (15K inital, 30K from then) If you tow frequently, 15K is a good interval. BTW, are you going on what some service writer told you or what it says in the maintenance part of the ownersmanual. Go with what's on paper, not what some service writer schlub tells you.

You are correct RE the AAM 11.50. It has the four-inch tubes, while the GM version starts at 4" and then is swaged down to 3.5". The Dodge also has an advantage in that the optional limited slip is a gear type unit (ala the Torson or the Trutrac), not that Eaton Locker (aka "Gov-Lok") that GM is so enamored about. It's a very stout axle and shares any of the best characteristics of its ancesstor, the Saginaw 10.50", also known as the GM 14-bolt, on of the best axles of all time.

 

[TheTanSedan]

You'll find other posts around here supporting 12-15m mile changes. Shoot, it's easy enough. I like Red Line.

 

[Joseph Fihn]

I have an '03, 3500 with that same axle. I've changed out the gear oil twice, now. At 15,000 miles, the stock gear oil looked kind of nasty. Gray in color with wear in debris, in it. The gray is from a lube they put on the gears at the factory. This gear oil change is a good idea & I wish I had done it sooner than the 15,000 miles, just to get the break-in materials out of the axle housing.
The second change was at a bit over 30,000 miles. That gear oil looked almost like brand new. In my opinion, that change was a waste of time & money. I used the Mopar product on the first gear oil change. Got the dealer down to $15.70/qt. They wanted $21.00/qt.
This last gear oil change, I used RedLine 70/90, at $7.00/qt.
The Mopar gear oil is a Texaco product that is re-labeled for Mopar. I called Texaco to see if it was an "off the shelf" oil. They would not say, probably because they do not want to jeopardize their relationship with Mopar. Mopar would like you to believe it is a "specially-made" product, just for Mopar. I called the local Texaco Rep. & he said that he did not think Texaco was making special oils, just relabeling their off the shelf products.
My guess is that the RedLine is a superior product.
If you check your manual I believe you will find that the recommendation is for a 70/90 gear oil, not specifically the Mopar 70/90, only, with a Mopar Part Number. Now, the NV-5600 stick shift does give you a Mopar part # that they recommend.

I also, called American Axle & asked about the 15,000 mile OCI's & they thought that was overkill except for the initial change.

I tow, a bit, with my truck & live in the desert SW with high heat & mountains. That's a lot harder on all your fluids.

Jim Allen,
Thanks for your excellent explanation of the AAM Axle's in the Dodge application. That would be very appreciated on the Turbo Diesel Register.com & Diesel Truck Resource.com websites. Please consider posting the information you have at these sites. Thank You.

Joe Fihn

 

[1sttruck]

I don't tow and the OEM oil in mine looked like black snot at 15k miles. I used Mobil 1 75W90 for the change and at the next 15k it looked like a darker olive oil. I put Mobil 1 75W140 in and will go 30k, although I may put 75W90 back in the front.