more pinion angle fun

[rockdogz]

I've been reading up on pinion angle, and I still don't get it.
My measurements are:
drivetrain angle pointing 1.4 degrees down (measured by bottom of oil pan)
rear end pointing 2.2 degrees down (measured across face of rear end housing perpendicular to ground
So is my pinion angle -3.6 degrees?

Some more measurements that may or may not have any bearing:

driveshaft is 3.1 degrees down towards rear of car
ground sloping 0.3 degrees towards rear of car

[race-rodz]

yes...kind of. im not too sure how accurate the oil pan is, if you cant check it at the tail housing on the trans, check it on a machined surface.

if the trans points "down" x degrees, and the rear points "up" x degrees, then the working angle is zero.

1.4* down doesnt sound correct, the drain angle is usually about 3-5* from level, this just happens to be the same as the pinion from verticle.

i cant remember what is the "normal" working angle on leaf spring cars, but i think its about -2-3*

[XcYZ]

FWIW, I recall asking Kyle at DSE what he recommends for pinion angle with his springs and it was -3*.

[rockdogz]

Yeah, I've heard -3 degrees is what you want.
I guess I'm wondering what I have - is it -3.6 degrees? That's what I don't understand... thanks!

[sinned]

Kyle's recommendation of -3* is not the working angle. The working should always as close to zero as possible without actually being zero.

All measurements need to be accurate. You need to remove the drivesahft and measure at the tailshaft of the trans and across the pinion face where the ujoints mate up. Also measure the tube itself to determine the working angle. Get all those measurements and I'll put together a small jpeg depicting what you have and why the angles are what they are. It always helps to "see" what you are trying to understand.

[rockdogz]

Thanks Dennis, I will do this.
When you say,

Also measure the tube itself to determine the working angle

does this mean the driveshaft? Because I measured that and it's sloping 3.1 degrees down towards the pinion.

Thanks,