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fakessturbo
03-15-2008, 09:18 AM
What is the maximum downward pinion angle I can use?
1BADAIR
03-15-2008, 09:34 AM
depends on suspension and use.
fakessturbo
03-15-2008, 11:24 AM
1930 model A, 350/350.

The rear is coilover with hairpin control arms. Assume the trans is installed level.
dave89iroc
03-15-2008, 11:43 AM
race car, or street car?



street car is ok to have 1-2 degrees down, but make sure that both ujoints have a couple of degrees on them(not strait), or they will not lubricate properly
Way2Slow
03-15-2008, 11:44 AM
Depends on transmission angle also!
dave89iroc
03-15-2008, 12:27 PM
Depends on transmission angle also!

he said assume the trans is level
fakessturbo
03-15-2008, 03:06 PM
My understanding of pinion angle is the it should be the opposite of the transmission angle. The line continuing from each should be parallel. So if the trans is +2 degrees, the rear should be -2 degrees if the installed height in the vehicle of both parts are the same.

The question is what is the maximum angle I can point the pinion downward?
dave89iroc
03-15-2008, 03:38 PM
My understanding of pinion angle is the it should be the opposite of the transmission angle. The line continuing from each should be parallel. So if the trans is +2 degrees, the rear should be -2 degrees if the installed height in the vehicle of both parts are the same.

The question is what is the maximum angle I can point the pinion downward?

no real max, if the lines are parallel

and it won't hurt if the pinion is down slightly more, as it will rotate up a little under power


but IIRC, you don't want more then ~10 degrees in the joints, as you still need extra for axle movement
NVR2FST
03-15-2008, 05:48 PM
-2 to -2.5 is a good place to start.
Way2Slow
03-15-2008, 06:28 PM
I missed the trans was level, -2 to -4 will work without any problems.
fakessturbo
03-15-2008, 06:35 PM
Thank you gentlemen.

I cut the control arm mounts off today and I am fabing new ones, shooting for 2 degrees down on pinion, shimming the trans +1 degree. It also makes the carb more level.
Detroit Gearbox
03-15-2008, 09:59 PM
My understanding of pinion angle is the it should be the opposite of the transmission angle. The line continuing from each should be parallel. So if the trans is +2 degrees, the rear should be -2 degrees if the installed height in the vehicle of both parts are the same.

The question is what is the maximum angle I can point the pinion downward?


that is correct.....5% max....less the better


thats 2.5+2.5