3 rd gear vibration???? 4L 60

[SSlowBoat]

Auto should be closer to -1-2

[95TAVert]

U joints

One day I had no vibration, pulled tranny and reinstalled now vibration is mainly in 3rd gear. But very noticeable,
Question, could the one to one 3 rd gear ratio have anything to do with it? And if so? How?

[SSlowBoat]

harmonics, pinion angle, etc could all play a factor, you dont have a nice rubber bushing soaking that up now. could even be gear noise. my firebird did that, only at 70mph on the highway it would vibrate like hell, thought it was the trans,then this, then that, here all along it was the gears harmonics coming thru the trans mount. gears ended up being shot

[95TAVert]

harmonics, pinion angle, etc could all play a factor, you dont have a nice rubber bushing soaking that up now. could even be gear noise. my firebird did that, only at 70mph on the highway it would vibrate like hell, thought it was the trans,then this, then that, here all along it was the gears harmonics coming thru the trans mount. gears ended up being shot

I definitely need to double check my angle and I think I pick up a rubber. Mount and install it to see. My 9 in only has maybe 500 miles on it so I don't want to destroy them. Thanks Tubby

[CPT]

Get the car running at a given RPM is 3rd and notice vibration. Then het it running the same RPMs on O/D. Is the vibration the same? Now try the same test using MPH and see if the vibration is the same between 3rd and O/D. Why did you have the trans out? It's very possible that you have the driveshaft 180 degrees out.

Frank

[95TAVert]

Get the car running at a given RPM is 3rd and notice vibration. Then het it running the same RPMs on O/D. Is the vibration the same? Now try the same test using MPH and see if the vibration is the same between 3rd and O/D. Why did you have the trans out? It's very possible that you have the driveshaft 180 degrees out.

Frank

i will check the speed and rpm's. I looked to see if the driveshaft was out of time, but I am not sure how to tell? I will find out. The tranny was out to install 2 and 4 gear sonnax billet servos, install went great and it shifts awesome.

[95TAVert]

Get the car running at a given RPM is 3rd and notice vibration. Then het it running the same RPMs on O/D. Is the vibration the same? Now try the same test using MPH and see if the vibration is the same between 3rd and O/D. Why did you have the trans out? It's very possible that you have the driveshaft 180 degrees out.

Frank

Hey Frank
i had tranny out putting servos in it. I turned shaft 180 but no change.
i tried the rpm and mph and the mph was it. At 45 mph was the worst.

[CPT]

Try a stock mount. It will atleast eliminate that variable. A new vibration after poly mount install is a VERY common complaint.

Frank