4x4 Problems - 2002 XLT please help

[cmajor]

I have a 2002 XLT - I just had a new differential and transfer case installed because the 4WD was getting false signals to engage, but wouldn't engage all the way - so I felt a tugging/bumping when I accelerated to about 45 mph. Anyway those parts got trashed, and had to be replaced. I can stop the bumping by pressing 4wd high, but as soon as I put it back to auto it starts bumping again. By the way the 4wd low setting does not work at all.

Please help, I can't use my truck and want to know what i'm talking about before I go to a dealership and get bent over...

Thanks in advance!

 

[BrooklynBay]

Welcome to this forum! You should have a warranty if they were replaced recently.