If they added the friction modifier to your LSD--which according to your sticker--you do have, it needs to be drained and refilled. Neither the front or the rear diffs on the 2500's with or without a Limited Slip Differential package use the additive (friction modifier). Make sure its properly filled(3/4" below fill hole).

The friction modifier is used in the 9.25" lc (light corporate) diff's with LSD to help the clutches slip during turns so they don't chatter.

Hope this helps

 

i asked them at the place and they assured me its the right stuff, but i want to change it anyway myself! what is the best rear diff fluid to use? Also the rear deffinatly chatters when i turn! I also remember that the guy i bought the truck from only used amsoil products on the truck, this time they used valvoline products and im sure its the cheap stuff, but i am almost positive that this started almost right after the oil was changed! let me know! thanks

 

I use amsoil in my 2500, it has going on 97,000 miles and has never chattered. Stay with a synthetic for best results. Mobil 1 is good, Royal Purple is good---you get the idea

 

According to my shop manual, ALL Trac-Lok diffs require the additive.

 

I have the FSM for the 2003's and it states in there that the friction modifier is not required on the 10.5" and 11.5" limited slips (with the Mopar fluid). I know for a fact I replaced my diff fluid with Amsoil Severe Gear 75W-90 (factory spec gear lube viscosity) and I got chatter. I then added a tube of friction modifier from Autozone and the chatter was gone within 100 miles.

My recommendation to Quikhemi is to just add the modifier and if you feel so inclined you could replace the diff fluid as well.

 

THANKS i think im going with the modifier just because it makes sence why its chattering if i had the fluid changed and they deffinatly didnt add anything to it!