Engine/Transmission (1998.5 - 2002) differential oil ?

[jeffohv]

I need to change my diff. oil in both the front dana 60 and rear dana 80 If I understand correctly the factory requires sae 90 wt for the dana 80 & sae 80 90 for the dana 60. would it be better to put a synthetic oil if so what type and quantity do I need? truck is 02 3500 4x4 dually I tow 38' travel trailer

Thks Jeff

 

[JKinney]

Done mine today Have yet to fill them the silicone is setting up amsoil 75/145 syn rear, 75/90 syn front.

 

[Supermod56]

There are several good synthetics out there, if you tow a lot, 75/140 in the 80 is a good choice, I use Redline Lightweight "Shock-Proof" in mine, works great.



Tom

 

[jeffohv]

Thanks for the Reply, when you did yours did you clean either of the out with some type of solvent I had heard of someone using brake fluid. I guess it woul depend on how dirty the diff is

 

[JKinney]

When I change mine I use no solvent I lift each wheel as so to drain all the fluid and refill.

 

[DIESELWRKS]

I just did my D-80 with royal purple dont tow alot it took 5 1/2 qts, with not lifting wheels and cleaning out as much as i could with a rag, didnt use solvents due to it will strip the oil that has bonded well to the diff, IMO. I did use brake cleaner on a rag to clean the surface for the cover. I used mopar ATV-RTV good stuff not so much of wait and cure time did it all in about 45 min. good luck.



Dieselwrks

 

[Diesel Gunner]

I used Chevron Delo ESI 85w140 in the rear and Delo ESI 80w90 in the front. It lowered my rear axle temp about 15-20 degrees when towing the TT. Don't have to add the additive. So far, I am happy with it

 

[XJJoe01]

I am using amsoil 75-140 in mine. I replaced the factory cover with a mag-hytech. It took 7 qts. I didn't have to use any LS additive. So far, so good.

 

[Texas Diesel]

I think the synthetics have a real advantage here. I have a temp gauge on my rear diff amd I had a lot of dino 90W laying around too, so I decided to experiment. Since the truck is a daily driver, 50 miles one way, I picked days with morning temps of 70F to make temp reradings on. The following readings are all with the MagHytec cover (yes I wasted a lot of good oil but I liked the temp data)



Dino at work arrival, 200F.

Next change, Mobil 1 75W-90, 180F.

Next change, back to dino 90W, 200F.

Next change, Royal Purple 90W-150 (whatever) 180F.



Interestingly I read on the Eaton site that they would extend the OTR truck rear diff warranty from 100,000 miles (with the OEM oil) to 700,000 miles if the owner/operator would switch to Mobil 1 ( and save the service receipt).



I have had a ring & pinion fail with a certain brand, which I would avoid, PM me if you want the brand name and details.



Made a believer in Mobil 1 out of me.



Also, I cant see why the front *needs* syn though since it doesnt do any work (unless you dont have a CAD)

 

[KSharpe]

Jeff, Im an AMSOIL Dealer. Go to my web site www.lubedealer.com/kensharpe click on store, that will get you the AMSOIL site. Then click on the Application button. From there enter your trucks info and you will get back a complete product info guide for your truck. Feel free to e-mail me at -- email address removed -- or call me at 308-284-8438 after 5pm weekdays.

 

[Diesel Nut]

I tow 13K lbs and tow quite a bit, and always use the Amsoil 75w-90. I have never seen a need for a heavier wieght. I would definetly go synthetic. You just have to make your choice based on what works for you.

 

[jeffohv]

Thks for the reply

 

[jeffohv]

Thanks for the reply



I would like to know the oil that was the problem

 

[RustyJC]

My owners manual specifically called for changing out the factory 75W-90 dino lube for 75W-140 synthetic for heavy towing. I ran the Mopar 75W-140 synthetic in my previous 1996 3500 dually and switched to Royal Purple 85W-140 synthetic in my current truck. You can see in my signature what I tow. Although one can argue about the need for the 140 as opposed to the 90 weight hypoid gear lube, running on the Interstates towing what we tow in 100+ degF Texas summers makes me side with Mopar's recommendation. I've never had any differential problems in either truck.



BTW, the RP did not require any supplemental Mopar friction modifier for my limited slip differential - it's already blended into the formulation.



Rusty

 

[2-ND TIME]

differential oil

I have been using Mobil 75W/90 for years and it is the only thing that hasn't given me a problem. (so far) do add the rear diff additive I added extra as was said in one of the tdr issues back awhile ago, and the clutches work as they should. So happy there.