what is the best way to correctly align a known good tailshaft to a different diff and trans (good tailshaft from another 2+2 basically). At the trans side the shaft can go in 2 different splines 180 deg apart at the diff there are 6 possibilities. Manual suggest to check for rounout and keep rotating 60, 90, 120 deg etc until lowest runout is reached. Any other methods ?
Not really. Measuring runout is the easiest. Otherwise, jack up the back and keep changing the position of the tailshaft and running the car up to 100k's or so and going with the one that has the least vibration.
Is this a one piece or 2 piece shaft? The tailshaft doesn't get aligned with the diff or trans, it gets phased to itself, ie- if it is a one piece, during manufactor the front and rear yokes are set on the same plane, then the whole lot is balanced. If it is a 2 piece, they assemble the halves similar to above and balance them individually, then they are aligned together and rebalanced. A 2 piece shaft will have 2 balance weights, one on the front half, one on the rear half. Assemble the 2 halves with these weights approx 160 deg apart. then bolt the whole thing into the car. If you have had the centre bearing off to replace it and didn't mark the parts, it will need to be rebalanced again, unless you are very patient.
The manual does specifiy that you adjust the tailshaft at the diff until the runout is within spec. PD-7 in the service manual for those who are playing at home And weights 160deg apart? Do you mean 180deg?
its a stock 2 piece with a good center bearing. I know the zed it came out from and it had absolutely no vibration. So you are saying that it doesn't matter how it goes on the diff ? manual clearly states that you should make a match mark on the diff and tailshaft end when removing....
So are you having vibration issues at the moment with the new tailshaft? If so it could be: Rooted engine mounts Rooted gearbox mounts (I reckon this is what causes the centre bearing to fail in the first place) Rooted diff mounts Rooted gearbox internals.
I know the manual states the runout but it isnt an issue. Both the pinion flange and companion flange have concentric drilled holes. You can simply loosen off the bolts and moveit the desired ammount without actually rotating it. No, not 180, they dont line up like that, dont ask me why.
no vibration issues just putting things back and upon inspecting the driveshaft the center bearing doesnt look the best . I've got another good one so am thinking of just putting that on instead of bothering with the stuffed bearing. Will measure runout just to see what happens. thnx for clarifying
