Rear diff or transfer case hit while boosting

[AlphaVision]

When I am driving the car normally it drives well.

When i hit the pedal and the car is in high boost I get a loud hit coming from the rear. Like a hammer smashes my crossmember or I hit a huge rock under my car. Or at least I think is in the back. My guess is the rear diff or maybe the transfer case. What could possibly do this? Is it a bad transfer, broken gear(s) in the rear diff.

 

[95gst16g]

I am not sure but if I were you I would first jack up the car and go through all the bolts and make sure they are all tight.I am FWD but I had a sound like you described but from the front.I jacked it up and went over all the crossmember bolts.One was really loose and I cranked it tight and have not heard 1 clunk since.

 

[AlphaVision]

I will check those. Thank you.

Just to add that I just did an AWD swap and started driving the new AWD car on Sunday. I got my parts fron a non-runnig car and don't know on the conditions of the rear diff and transfer case. Transmission is rebuilt.

 

[JackM]

Sounds like loose rear diff bushings. The rubber is always bad in those...

Jack

 

[black_gst]

yeah rear diff bushings for sure

i made a custom set for my car and a few others

check out the link... pm me if you have any questions

http://www.dsmtuners.com/forums/drivetrain-tech/339619-your-rear-differential-bushings-bad.html

 

[AlphaVision]

Actually I got brand new UMS Tuning v2 bushing set (3 pieces) for the rear diff. I had to reinstall those because they have direction and the first time I mounted the diff the polyurethane was coming out of the aluminum housing. So after I turned them they were positioned so the front was stopping the rear from coming out and vice versa.

This weekend I will check them if they are loose.

Thank you, guys.