Tolerance setting pinion angle ?

[unklian]

How close is good enough, at ride height ?

Late 60's C10 PU, with the long truck arms. Street/strip.
Been lowered all around with coils.
HAD tapered shims installed on the rear end.
Something was wrong with the assembly,
the shims split and came out during a burn out.
I suspect the shims were cast aluminum,
and had been over torqued.

Rear is out, raising the front trailing arm mounts,
to improve antisquat. Will check pinion angle at reassembly.

[jaybee]

I don't have a firm number on it, but a lot of people will tell you the pinion should be a degree down to compensate for pinion rise under power. Others disagree. I'd guess the number is somewhere north of 2 degrees.

[enjenjo]

Does it still have a two piece driveshaft? If it does, you may have to move the center bearing too to make it right. You generally want the pinion up one degree less than the trans is down. If it has a two piece driveshaft you have to figure pinion angle off the rear of the front shaft, but no Ujoint should have an angle over 5 degrees.

[unklian]

ok, thanks.

I think he is running a one piece drive shaft now.

[Digger]

In theory, for normal driving the U-joint end of the pinion should be up the same degree the trans points down. However if you are doing a lot of racing it should point down one or two degrees.

[PeterR]

How close is good enough, at ride height ?

Rear is out, raising the front trailing arm mounts,
to improve antisquat. Will check pinion angle at reassembly.

If the vehicle has a one-piece shaft and height of the front mounts is altered, there is a likelihood plunge will be introduced in addition to difficulties with maintaining complimentary UJ angles.

A two-piece shaft provides a lot more freedom to reduce plunge and also to tweak angles, particularly if the center joint is a CV joint, either the traditional double Cardan type or the Birfield style.