I'll get this out of the way quickly, I've had nothing but trouble from this truck. Not the worst vehicle I've ever owned, but pretty damn close.

Last year I had to service the parking brake. Like any normal engineer would do... make it easy to service. Not Dodge! F*&king morons. So I had to pull both rear axles to get this done. Replace seals, etc., no big deal. I filled the diff with Mobil1 LS 75-140 per recommendation of several previous posts, no additional friction modifier necessary. This was over a year ago, but I maybe put 2000 miles a year on it. It mostly sits in the barn until I have a project to work on or a trailer to haul.

Now I can feel the rear end starting to shudder under acceleration, turning or straight. There are no other ill effects other than the shudder. It disappears once I pick up some speed.

T/Case DJMS 205MM HD Front Axle DMH 3.92 Rear Axle Ratio DRBS Corporate 9.25 LD Rear Axle DSA Anti-Spin Differential Rear

What's the suggestion on the diff?

1. Start with 2oz friction modifier and see if it helps?
2. Drain and fill with Royal Purple?
3. Other suggestions?

On a side note. Has anyone ever done a frame swap? Mine has a pretty nasty rust split in the bottom sidewall of the frame near the center. I don't haul heavy loads, but I still pull trailers. Worth my time or should I wait until the cab and bed are touching? My 1 owner '70 Chevy has been through many northern winters and is solid as a rock. This '03 Dodge has been such a disappointment.

 

Adding in the friction modifier can't hurt, that's the first step.
I'm sorry you have problems, you've caught a lemon sir. I have 2 and they're the best trucks I've ever experienced.

 

The 9.25 LSD LC rear diff does require the friction modifier. The 2500, 3500 and up do not. Get the bottle of additive and all should be well again.

 

I'd start with adding some modifier. Even though synthetics claim to have it I always have had to use it in clutch pack type LSDs.

My '04 Ram with aftermarket Auburn unit would chatter from day one after a fluid swap if I didn't add extra.

My '02 Grand Cherokee Overland had Vari-Loks in both axles and it even would start to chatter on turns IN BETWEEN lube changes. So I ended up making it routine to add a couple ounces exactly half way between scheduled changes...

 

My 03' Dakota's SM said the same thing... pull the axles to replace parking brake shoes (the linings had fallen off the shoes, lol). I thought that was crazy and tried it without pulling them. It actually turned out to be quite easy. Not sure how your Ram is setup but if it's like the pics below, don't pull the axles next time.

https://dodgeforum.com/forum/2nd-gen...ne-soft-2.html