Odd problem.

[Matts94Z28]

This 12-bolt has done nothing but piss me off. Now I can't figure out what the hell is going on here. I have a chassis mount TQ arm with the angle set at -2*, the adjustable control arms are set to factory length, sportlines, and the shocks are summit 3 ways (the CE knock offs), which worked fine with the 10-bolt. The wheels are centered in the wheel well, so adjusting the control arms is out. I do have a set of LCA brackets that have yet to be put on the car, but I doubt that would be the issue... could be wrong though.

I can not figure out why the hell my shocks have such an angle to them. This has to be adding stress the shock bolt. Any ideas?

[bwelch]

Did somebody make that 12 bolt fit a Fbody or a company?

[Matts94Z28]

It's a Moser 12-bolt for a camaro.

[minytrker]

how did you measure pinion angle?

[Matts94Z28]

ds angle and pinion angle.

[AverageJoe]

Put the relocation brackets on and measure the pinion angle with the rear end pointing 2* down. If you do that, your car will be set up the same as mine and I dont have that problem with my shocks. If you want to check the ds angle, thats fine. But SET the pinion angle at -1 or 2*.

[minytrker]

I run pinion angle off the yoke of the rear end only with the car sitting on the ground. Thats also how Madman checked mine when I had my car there.

[BAD BOB]

maybe the drive shaft is bent so rotate it half turn and check it again

[Matts94Z28]

DS is straight as an arrow. Just had a new slip yolk put on it when the rear end went in. I am thinking it could be something with the bracket that mounts the TQ arm to the rear or maybe the top adjustment.

I originally had it set like madman suggested, but it had some vibration. The out come was still the same.

[brewerz28]

Originally Posted by minytrker

i run pinion angle off the yoke of the rear end only with the car sitting on the ground. Thats also how madman checked mine when i had my car there.

this!!

[gearmesh, inc.]

Pinion angle specs you hear from damn near everywhere are so vague if you ask me. They all seem to be referencing earth level and assuming that engine/trans centerlines are all at the same angle in reference to earth level.

What you need when the car is under power, is for your pinion centerline axis to be parallel to the transmission output shaft axis. That way, as the driveshaft rotates, the arc the front u-joint swings in is equal and opposite to the arc the rear u-joint swings in. That way any vibration that is generated at one u-joint is canceled out by the equal and opposite u-joint swing at the other end.

An easy way to determine the angle of your transmission output shaft is to put your inclinometer on the top edge of your valve cover. This will be pretty much parallel to your engine crankshaft and thus equal to your transmission shaft centerline axis.

Stock suspension bushings will need more down angle set in comparison to the angle of the transmission shaft to compensate for pinion angle change while under power. I would estimate 2 to 3 degrees for stock bushings. If you have poly bushings, or heim joints, your pinion angle at rest will be closer to your actual trans shaft angle. You may only need 1 or 2 degrees of lower angle than your trans shaft angle since there will be less rear housing rolling under power.

[Pesce Nero]

matt, your pnion looks like its pointed at the ground to me.

2 commom pinion angle methods

1. make crank center line and pinion parrallel, then rotate rear down desired amount
example, crank -2, make pinion +2 = 0 pinon angle. then rotate rear down 2-5 degrees. this method your pinion may be 2* down but actually be 4* by this method

2. ds and pinion. somtimes guys mess up math/or angle up or down on this method

a -2 ds and -2 pin =-4pa.

[minytrker]

Originally Posted by Matts94Z28

I originally had it set like madman suggested, but it had some vibration. The out come was still the same.

If you set it like I posted it will not be angled down like that, unless you are miss-reading the angle gauge. I could see it having a vibration how it is. If it had a vibration like I posted then you have something out of balance or a bad u-joint.

[Matts94Z28]

Trying to get some pictures of the pinion angle. I don't think that is the issue. I will get it in the garage and re adjust.

[1iron]

Looks like that shock bracket is to far forward or the pinion is to far down. The disclaimer is that I don't know much about camaros or turtles.

[ElecTech]

Could it have been set up for a relocated shock package? The brackets have to be wrong in some way.

[Matts94Z28]

Originally Posted by ElecTech

Could it have been set up for a relocated shock package? The brackets have to be wrong in some way.

You know, that is possible.