My gearbox and axle flanges are not quite parallel. How much of an angle is permissible before it becomes a problem.
Looking at the engine angles on some cars makes me wonder if some installations suffer prop vibration, either due to the engine tilted back or pointing off to one side.
Advice welcome.

If you had built the car as per the book, the angles would of been much better !!


(only joking!!)

You could argue that a perfectly aligned prop would concentrate the wear to a small
area of the UJ, a slight angle actually helping things.
Look at a Land Rover of most high 4x4s, the props tilt at quite an angle.

We don't live in perfect world, you should see the change in flange angle on the stock Mk3 to 5 Cortina between full bump and full droop, much same goes for cars with plain semi-epileptic leaf springs from spring wind up due to torque reactions.

Take a look at my post at:

http://www.locostbuilders.co.uk/viewthread.php?tid=145955

There are some acceptable tolerances in the above links but they are small. Totally agree with BT about the angles but with a fixed diff you should aim to close to the ideal, after all most of the misalignment with a live axel is only temporary whilst under acceleration/deceleration so it is not sustained..

Shame linkys broken in above post, it did honestly have the tolerance! I would ring one of the prop manufactures for peace of mind...

Cheers

Dan

[Edited on 11/10/11 by Bluemoon]

There's some confusion going on here...
In an ideal world you want the two flanges parrallel (as I think you mean) with each other, but off-set (as NigeEss suggests) is needed to prevent premature wear. In reality the flanges being perfectly parrallel is not possible at all times given a moving axle, or very difficult to achieve with a fixed diff' given the distance apart makes it imposible to measure accuratly.