Pinion Angle! Stock settings?

[NateCharger]

What pinion angle did the 71-74 B-bodies come off the assembly line with? The reading at my tail housing is 2 degrees down. That is with the new Energy bushing in the transmission mount. How can you have a pinion setting of 5-7 degrees down, if the tranny is tail down as well? I have read so many threads, I'm getting dizzy.

[68CoronetRT]

Need to figure out where the trans angle is first. I've been reading alot about this today and what I've found is pretty simple. If the trans is 2* down, the pinion needs to be 2* up, creating a zero degree situation. You can shim the pinion up or down depending on what the trans is.

I'm sure some others will chime in on this.

[NateCharger]

Transmission output is 2 degrees down, driveshaft is 3 degrees down, pinion is 1.5 degrees up. Bad radiating vibration at 35 and 60.

[Paul G]

Those pinion angles should'nt cause a vibration. Is the trans mount centered? Meaning is the trans sitting in the correct left to right position?

U joints in good condition?

Is the energy bushing a poly bushing? If so they will transmit a lot of vibration in to the car, a lot. I have a poly trans mount sitting on the shelf. I hated it. 

 

[NateCharger]

Got transmission to 1.6 degrees down, driveshaft is at 2.4 degrees down, pinion angle .7 down. Vibration almost completely gone! The shop I had weld my perches on made a huge mistake and welded them on at nearly 5 degrees....UP! So I stuck a 6 degree shim back there. I am amazed that a speed shop could make such a huge mistake. I spent a lot of hours tracking down the vibration, never thinking to check the shops work. In order to properly fix it, I have to have new perches welded on correctly...