I think i have bad u-joints and i bought 2 brute force ones from advance auto parts. they look the same but looking in the chilton manual it says the borg warner rear end uses the same u joints but the signisaw(sp?) uses a different rear. i think i have the signisaw rear so do i need a different u joint?

when shifting the car from park to reverse or reverse to drive the car clunks and sort of wants to take off. is that u joints? i already replaced the tranny mount.