Pete Watson wrote:
> Do cv joints support axial loads? If I'm not mistaken, the
> Spitfire relies on the axle itself to maintain lateral location, which
> would pull apart a cv joint if it couldn't retain the axle.
I suppose it depends upon the construction of the cv joint--in most, the
axle shaft does slide back and forth, to accommodate geometry changes.
In that type, the axle is usually pinned or c-clipped to the inner
portion of the joint. The inner portion of the joint then does the
sliding, and is limited by the balls or post bearings in the joint.
That limiting is pretty substantial, so there's not much chance of the
joint itself being pulled apart.
Therefore, the real detriment, as you say, is geometric--the weight of
the car on the rear wheels would pull the inner half of the joint
outward toward its limits, and the rear wheels would go to more negative
camber, eventually limited by the end and side play in the radius rod
bushings. I suppose at that point, if there were a side load high
enough, the axle might be pulled from its clip or pin. I suspect that
one couldn't stand the noise from the radius rods before that point.
That said, a single-plane cv joint (one which does not accommodate axle
travel) would be superior to a u-joint, because of its ability to
tolerate much higher angularity, and for the ability implicit in the
name--constant velocity, and therefore, uniform torque transmittal.
And, then there's the machining expense associated with adapting the
axle to a non-standard joint. One can buy a lot of u-joints for that.
<g> And the replacement cost of the cv joint is considerably higher.
> It's a
> swing-axle, like early VWs, with just one u-joint at the inner end of
> the axle. The deflection easily exceeds ten degrees (if driven
> properly 8^) ).
It is a swing axle, much like older VWs, but with a couple of important
differences--the VW used a substantial swing arm/torque tube/torsion bar
arrangement to keep the outboard bearing housing located because the
u-joint wasn't really a u-joint, but rather, was just a spade on the
inboard end of the axle which fit into the side gears with a couple of
trunnion blocks, along with a locator for the torque tube.
My other Triumph doesn't run, either....