Here's a couple of opinions of mine that I'd like to throw out there for cannon fodder:

1) Changing pinion angle can not, and will not improve traction.

2)Since our U-joint system is not a constant velocity type, the centerline of the pinion should be parallel to the centerline of the crankshaft and the pinion angle (with respect to the driveshaft) ends up being whatever it ends up being.

3) The only reason to run negative pinion angle beyond what is needed in statement #2 is to accomodate a lot of suspension wind up.

Fire Away !!!!!!!!!

Steve

 

Agreed.

You should feel us in with some schematics of the IC of a Camaro.

Ben T.

 

The pinion gear wants to climb up the ring gear upon launch; setting a negative pinion angle compensates for this motion and gives you a "straight driveline" under hard acceleration. Yes, if there wasn't any dynamic driveline change, you wouldn't need to compensate.

 

Assuming you get the angle correct, you are right. But what if the pinion angle is not correct, and the u-joints (which you correctly point out are not CV units) start to fight each other, because they are not "equal and opposite"? It's conceivable that this could induce cyclic lateral forces in the rear axle that could reduce the control on the rear suspension components. Just thinking out loud......

The greater the displacement of the pinion shaft axis from the tranny output shaft axis, the greater the angle between the DS and the other components. The larger that angle gets, the greater the loads on the bearings, meaning more wear and more power loss.

I like your point though, and its something that bothers me every time I see the recommended measurement procedure, looking only at the DS and the pinion shaft. The objective of aligning the tranny/driveshaft/pinion shaft should be first to insure the tranny and the pinion shaft are parallel. Looking only at the angle the driveshaft makes with the pinion shaft is not necessarily meeting the functional requirements of the u-joints. The goal should first be to insure that the tranny and pinion angle are parallel, then to insure the offset is minimized.

Sounds good. The goal is to have the front and rear u-joint angles equal under max load.

 

Absolutely! I throw my angle finder in top of the nicely machined fins of the intake manifold, and compare that to the centerline of the pinion. I believe that the Torque Arm machined flats are parallel to the pinion CL but haven't done any precision measurements to verify.Also, I have found that off the shelf plastic angle finders really don't have enough resolution nor do they have the R&R to do a good job of setting angles. I've been borrowing a digital from work and it's good to .100 degree. Maybe I'm a bit **** on this but "you can't make what you can't measure"

Steve