[blueallie]

Don't want to lead you astray with my ideas , but something weird is going on

My mechanics at work are even perplexed. They keep telling me it’s the driveshaft. We checked the angles after popping the new shaft in and can’t go above 50mph without teeth rattling vibrations. Pop the old one in and it’s smooth up to about 65-80. Old one has a slight vibration but nothing terrible. To me it points to the driveshaft. But the builder is denying that anything is wrong with it.

 

[sherlock9c1]

This is a screen grab from YouTuber Precision Transmission precision transmission of a 1999 4L60E tail shaft bushing with the original bushing in place. Just FYI.

 

[buickman1]

My mechanics at work are even perplexed. They keep telling me it’s the driveshaft. We checked the angles after popping the new shaft in and can’t go above 50mph without teeth rattling vibrations. Pop the old one in and it’s smooth up to about 65-80. Old one has a slight vibration but nothing terrible. To me it points to the driveshaft. But the builder is denying that anything is wrong with it.

Regardless what the builder says you have tried both shafts and the new shaft is worse. Sounds like the builder doesn't want to admit he [email protected]#ked up, try sending him a video clip of the problem.