Great forum, thanks for including me! 2000 dodge 2500, 4WD, brand new dealer trans, recent rear end done, driveline balanced and new u-joints- when i hit 45-50, and overdrive kicks in, I get a shudder as if I had a u-joint or support bearing out- Ive had several recommendations it could be the transfer case- Any ideas?/..Thanks..Barry

 

Sounds like a TC issue.....crappy dealer rebuild TC perhaps?

 

About 42 to 45 is when the converter locks up depending on where your foot is.
New trans or a Dodge reman?
Who did the job? Is it filled with the correct ATF+4?

 

I'll give my vote for a bad TC as well.

 

This may sound crazy, but pull your negative battery cable and ream the connector and post. Also pull and clean your grounds.