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Phasing the driveshaft[120-130/1968] posted by JohnH on
Wednesday, 12 April 2000, at 1:53 a.m.
Help please. I know the driveshaft must be phased to avoid vibration, but how is it done? I did mark where the flanges mated at the gearbox and diff when I pulled the shaft to replace the yokes and bearings, but I forgot to mark the relation between the two shafts in the middle where the spline joins them.
Re: Phasing the driveshaft[120-130/1968] posted by Jason Kneier on
Wednesday, 12 April 2000, at 11:11 a.m.
Well, you're down to two possibilities - the u-joints should be at right angles to each other, so there are two orientations that could be right. If there aren't any kind of stray marks, smudges, grease stains that line up at the shaft junction, I think you'll just have to guess and try it out. If you get bad vibes, swap orientations and try again. And next time be sure to mark the joint :) !
--Speed Racer '83 240 'R, '74 164 E, '93 940 OL1 (Smithfield, NC)
Re: Phasing the driveshaft[120-130/1968] posted by George Downs on
Wednesday, 12 April 2000, at 6:16 p.m.
As you know, a U-joint has 2 yokes connected by a cross.
The yokes are 90 degrees apart. When you stab the slip
joint you are making 2 parts into a single shaft. On this
single shaft the yokes at each end need to line up exactly.
(look at the other shaft and see how they line up on it.
When you get the slip joint stabbed right, the 2 yokes on
that part of the shaft will be lined up the same way.)
This will minimize end thrust introduced by the angle at which the
2 parts operate, and thus also minimize endwise motion of the
slip joint.
If the shaft is properly made, luck is not involved.
--George Downs, provisionally in Augusta, GA
Re: Phasing the driveshaft[120-130/1968] posted by JohnH on
Wednesday, 12 April 2000, at 8:50 p.m.
Thanks George,
If I understand you correctly this means that I should engage the splines so that the front Ujoint will be oriented exactly the same as the middle one (which is at the front end of the rear shaft). Then the gearbox Ujoint and the diff Ujoint will line up.
i.e. the inner yokes at each end of the joined shaft are parallel to each other (as are the outer yokes).
Am I correct?
Re: Phasing the driveshaft[120-130/1968] posted by George Downs on
Thursday, 13 April 2000, at 11:22 a.m.
What you want to go by is the front shaft,
in spite of the fact that it has a slip joint in it, the
2 yokes on the front shaft should be aligned perfectly with
each other. The rear shaft's 2 yokes will be at 90 degrees
to the 2 yokes on the front shaft(with slip joint between
them).
Look at the rear shaft and you can see that the 2 yokes
are perfectly aligned. (Disregard the rest of the U-joint)
You want the front shaft to be the same way, except that
there is some stuff between the yokes. Since the least
you can be off is one whole spline it is pretty obvious
if it is not right, assuming you know what to look for.
What I do is put the tranny in neutral and turn the
shaft so the yoke on the front is vertical, then put it
in gear, then stab the rear one also vertical. You can
use any position to start but vertical is easy to identify.
George Downs, provisionally in Augusta, GA