It looks like these all call for GL-5. Does the rear limited slip require anything special. I was looking to put in amsoil or some other high quality synthetic but didnt know if the limited slip needed a special additive package.

 

Nothing special for the front or rear. Mine is AMSOILED thruout and I just love the stuff.
If I remember correctly the Xfer case uses ATF+4, which AMSOIL ATF does meet the requirement.

 

Hey guys, I wanted to put Amsoil series 2000 in the differentials. I'm not sure if I should use 75w90 or 75w140. For towing heavy most of the time, would 75w90 or 75w140 be better? I'm concerned about keeping the differential warm (as opposed to HOT!).

 

If you want to go stock, you'll need:

Front/rear axles: full-synthetic 75W-90. Some use Mobil 1, I like Valvoline Synpower.

Transfer case: ATF+4, which I have so far been only able to find at the dealer (for $8.00 per quart).

If you have an 11.5 inch limited slip unit, you require NO additive. If you have a 10.5 inch limited slip unit, you DO require friction modifier.

 

What about *gasp* ignoring the manufacturer's recommendations... ! I hear a lot people using the Amsoil synthetic ATF in the trans and t-case. I'm wondering if there's any sense using the thick 75w140 in the rear? Not sure if this would help any.

 

Ignore them. Follow them. Pick and choose. To each his own. I just wanted brillmtb to have all the facts.

 

I am one of those guys who went Amsoil all the way thru. 75W-90 in the diffs just like the manual called for (I'm not going to argue with the factory in this one). Used Amsoil ATF in the Xfer case and 5W-30 in the tranny.

Another satisfied customer.....

 

OK, very interesting subject, but, hear this one!

I have an 03 2500 CTD HO 6speed, 15K mile service coming up, after learning dealer wants $300.00 to change front/rear diff lube, I decided i will do it myself. I checked my owners manual to verify that front and rear uses 75/90 syn. with no additional additives needed. I call the dealer where I got the truck, service/parts rep says, and he tells me I dont need synthetic. I let him know what my owners manual says, then he tells me ok they have it, if I want to use it!
I then stop by a different dealer, service tells me NOT to use 75/90 snthetic, but to use 75/140 snthetic with 2 bottles of FRICTION MODIFIERS. He says DODGE made a change that requires 75/140 sny + friction modifier AND if a person dont use it and the DIFFS. start to chatter/fail Dodge WILL run a oil sample before honoring the warrenty. He says the 75/90 syn. will break down when towing. Very interesting indeed. So now I have no idea what to use. I cant even find a 75/140 syn. exept at Dodge--for 20 bucks a quart. Somebody call their local Dodge service dept and see what they say!

 

Gotcummins, RTFM. I know, but read it again. Look at page 340 of the owners manual. Note the "Front and Rear Axle Fluid 2500/3500 models" line. Says "GL-5 75W-90 Synthetic. Limited-Slip AAM Rear Axles DO NOT REQUIRE a limited slip additive". (My caps are actually BOLD in the manual). Show it to the service folks, bet they've never sat down long enough to read it. Though I bet they've "been to class" on it before. My advice is to follow the book, and keep receipts. Don't forget that the devil is into details.

The only thing that is tough to decipher is the PN for the NV5600 tranny if you decide to not use DC "oil".

My nearest DC dealer tried to sell me a Hemi Diesel; you think I'd buy a vehicle from them? LOL!! Not a chance. Your 2nd guy is talking Dana, not American Axle. He's probably too busy teaching his little boy to say "hemi" than Reading the Full Manual.

BTW, change the diff lube at 15k like the manual says. The "sparkly's" may thank you for it.

 

Ditto everything bulabula said.

 

Even AMSOIL will say not to add an additive to the rear end. The question about 75-90 vs -140 is if you do alot of heavy towing. If you do alot of towing you may want to put the 140 in the rear end and the 90 up front. The 140 is heavier and provides better cooling features, at least that's what two AMSOIL dealers have told me. If you only tow a boat on a weekend, then stick with the 90 weight in back and up front....
And, don't forget to use the DODGE ATV on the covers so they don't leak!

 

These AAM axles, front and rear, have re-useable rubber O-rings, and DO NOT require any RTV.

 

Humm, You may be right, but three different AMSOIL dealer's have told me to use the ATV sealer...I haven't done it yet, but atleast I will buy it and have it on hand incase I need it..

 

Since when are Amsoil dealers the experts on resealing diff covers? No offense.

 

Who said they were the experts? No offense taken....