Engine/Transmission (1998.5 - 2002) limited slip gear lube

[rborn]

I've had my 98. 5 3500 with Cummins about a year now. The differntial clunks, badly at times and not so much at others. Soon after I first got the truck, my mechanic added a small container of lube enhancer which solved the problem 90% at first, but now several months later it's back doing its clunky, chunky thing again. Any recommendations on lubes or lube additives that are the best?

 

[Muleskinner]

MOBILE ONE GEAR LUBE

I use Mobile One axle lube and put one tube of limited slip additive. This combination has worked fine for me.

 

[AKAMAC]

There is an advantage to doing your own maintenance; You see what comes out and you know what goes in. I'd pull the rear cover and look for damage. Post your findings so others know what to look for. I changed mine at 40,000 and added 2/3 of a tube of friction modifier. All is well with mine and the differental locks both. I'd try to change the existing fluid before doing anything drastic; IE: take it to a shop. Good luck Mike

 

[Tcolesanti]

The best friction modifier I've ever used is made by Dana, and as far as I'm concerned it's the only one out there. That stuff you buy at Napa or Auto-Zone does'nt work. Go to a driveline shop and ask them for Dana Friction Modifier-Its a bit expensive-oh, and DON'T GET IT ON YOUR HANDS.

 

[Big-D]

Royle Purple has worked just fine for me. It has the proper amount of friction modifier already. There are others as previously mentioned, but when you find the right one, stay with it.



It isn't hard to change your own rear end oil and I would certainly recommend you do it yourself.

 

[RBallard]

I have Royal Purple 85W-140 in my front and rear and I lost my limited slip. I bought RP because it stated it did not need friction modifiers which I guess it didn't because I didn' t get chatter but I didn't want to loose my ls either. I will be switching soon to something else and hope to get my ls back.

 

[Challenger-II]

My '99 is filled with Amsoil and I get chattering of the back wheels when accelerating around a corner in the rain. If I do figure eights in a parking lot on drive pavement it is fine. Do I need to add friction Modifier? Why would it chatter only on wet pavement in turns??

 

[GMincher]

Come on Amsoil guys!!! Actually it's not unusual for 'em to chatter on wet roads in turns. Just means your clutch pack is grippin' good! Dry roads create enough friction to make 'em slide against one another! I've used Amsoil for 14 years now in every machine I own. I'm sold! I'm not going to bash any other company, I just know what's worked VERY well for me!