Power Wagon Registry

2018 Power Wagon, 60K service.
Changed the differential fluid, had not performed the trans yet (waiting on parts)
Afterward, getting a grinding/catching/popping feel when leaving from a stop. Worse, when in reverse.
Research is indicating that the rear differential needs a friction modifier added to the fluid.
Dodge/Ram parts and service say that no friction modifier is required. My understanding is that the PW has a Torsen Limited Slip with an E-locker. Torsen has no clutches and shouldn't require a friction modifier.
What's weird, also, is that the rear differential fluid was dark, like clutch material in it.
This problem showed up right after the differential fluid change.
Thanx

I've experienced the same shudder after a fluid change. It's undetectable if you start from a stop in a straight line but if you're turning when you start out, that's when you feel it, indicating that it's related to the differential action happening inside the carrier. After I added friction modifier, it went away. I used high quality fluid but apparently it wasn't rated for limited slip applications.

Welcome to the forum!

I've got it in mine too. But wasn't till my 3rd diff service which I went with Lucas. Later on found I needed a R&P but after that the shudder was still there and I used Amsoil. It's barely noticeable now unless I have 12k+ pounds towing.

Was exactly same feeling as Abel stated.

What's really odd is you're correct, our LSD are not clutch based and should not need a modifier but I've seen many PW owners say after using a friction modifier it went away.

I've always used Mobil 1 gear lube. Never had that shudder.

Had the shudder in mine after servicing.

Took it by a local shop and they reserviced it and added Ford LSD friction modifier and shudder is gone with no further issues after around 5k miles.

Had the shudder in mine after servicing.

Took it by a local shop and they reserviced it and added Ford LSD friction modifier and shudder is gone with no further issues after around 5k miles.