Okay I have looked everywhere to find this but I can't.

I have a shuddering issue when accelerating from a stop. I can't tell if it is coming from the trans or the rear diff. has anyone had a similar issue?

05 XLT 5.4l 4X4.

 

when is the last time the rear diff has been serviced ?

 

Well I bought it used from a local dealership with 102k on it and they said they did a full service on the rig. But you know how that goes. I was going to check into that but with snow on the ground here I haven't got to it yet.

I would imagine that they at least checked it and made sure it was topped off.

 

They didn't check anything but the gas gauge.

Does it shudder going straight or turning or both?

 

Both, more noticeable when turning.

 

If they serviced it, they properly missed the Limited slip additive to your rear differential. Your best bet would be purchase it from your local Ford dealership and toss it in and hope that fixes the issue. The other way is the long route and do all new fluids yourself the proper way for a piece of mind.

 

First thing I would do is drain, inspect, and fill the diff - adding the friction modifier if it is a limited slip.

 

I guess that is the route I will go. Cheers

 

The chattering around corners is a sign of the clutch pack in the LS diff, unless they forgot about the friction modifier. My pickup had the similar issue around corners and I replaced the fluid and modifier. Then it still continually got worse over time and I ended up replacing the clutch pack. It cost me around $500 with labor. Hope this helps any.

 

Two piece drive shaft?