Date:         Fri, 8 Jul 94 10:32:36 GMT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         William Warburton <william@festival.ed.ac.uk>
Subject:      Re: cv-joints: Constant Velocity Marihuana?

 Hi,
	Right, I'm a little dubious about sending this, given my record so far
this morning :-( but:

Alistair Bell (a fine Scots name :-) writes:

> >flip the axles end for end so that the "other faces" of the cv joints
> >are taking the wear (when driving forward!).

 This makes sense to me- the only retarding torque on the CVs is under
engine-braking, a good deal less torque being transferred that way than
under normal driving.

Uncle Joel (the greasy one in the corner with a good line in stories) adds:

> aha! i've wondered about that for a long time!  if the outer joints (wheels)
> are re-positioned at the transmission ends, it would seem to me that the
> much smaller angle and up-and-down motion (of the transmission end) would
> mean less wear and tear on the joint...

 This I'm not convinced about- given that the drive plates at the
transmission end are constrained (by the torsion bar suspension) to
remain essentially parallel to the ones at the wheel end, it seems to
me that the angle subtended by the driveshaft must be identical at each
CV. I agree that the wheel must effectively do most of the moving but
in practice the geometry dictates that the angles that the CVs take on
must be the same.
 Intuitively the wheel does the moving, in practice the joints experience
identical motion.

 I may be wrong but if so then I would appreciate an explanation of why :-).

 As far as swapping the joints is concerned, I think that the issue is
whether it's better to use a "new" face in a joint (by reversing it's
rotation) or to leave it in the orientation to which it has become
accustomed. I don't really have the experience to comment on that but I
suspect that it depends on whether the joint will fail because of excessive
play (backlash?) or because the load bearing surfaces wear out. The bad
joint that I had (yes, that's singular- I *did* say I didn't have much
experience :-) was still tight but had pitted faces, suggesting that
swapping would be worthwhile.

Cheers,
        W.
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