HawkRod, maybe I'm missing it but here you said 4 degrees engine down 4 degrees pinion down.
In your thread you said "Now I haven't remeasured my driveline angles, but based on the angles I measured before, I should now be at about 2.0* down for engine/ trans, and 2.6* down on my pinion."
...and you still have some vibration.
Yes the pinion will rotate some, but not 8 degrees unless you have some seriously weak leaf springs.
OP's car under acceleration should be damn near perfect as far as u-joint cancellation and not so far off that it would vibrate under cruise, just as it is.
Just my opinion.
So first, thanks for carrying on a conversation like adults without resorting to name calling.
It's a shame so many threads break down to that!
1) I acknowledge my memory of what I read and what I wrote in my final results do not match.
My final results (last link in post #10) say that driveline should be down 3* and pinion should also be down 3*.
That is a 6* difference. I acknowledge that I wrote 4 and 4 above in my post #3. That was from memory and perhaps 4 is on the high side. I will go up and edit that as I will plead the old and potentially forgetful routine on the 4*.
...But the fact remains that experts way more knowledgeable than me state
both the driveline and the pinion should be down.
I will absolutely not claim any expertise in this area. As a matter of fact, as seen in my thread from 2022, I struggled with this issue A LOT. But the full story of my driveline vibration went back YEARS. I rebuilt engines, balanced drive shafts, replaced axles, swapped wheels, etc. You name it, and I tried it. I also finally tried shimming the pinion UP. Shimming the pinion up caused the problem to get worse, but it was the first experiment that measurably
changed the vibration. When I then shimmed it down, the vibration first improved, and then with more shims it
essentially went away. Yes, there was a tiny bit left at high speeds, but my thought on that is that I didn't quite shim it enough.
As far as my measurements: These were what I was able to measure. However, I am sure there could be some error in my measurements. It is not necessarily easy to get good contact points to measure the angles.
Since the OP has not yet tried his car and doesn't have actual results, I agree with your suggestion to "try it and see". But if he has any vibrations, I would suggest to shim the pinion down another couple of degrees.
