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Pinion Angle?

thelostartof

unbalanced chemical
300+ Club
Joined
Jun 26, 2002
Location
Apache Junction, AZ
Ok so Lets just say I put on a set of Solid yet adjustable torque rods on my 945. What should the ideal pinion angle be for these cars again? Yes I know I need to raise my T5 output angle also but that is besides the point.

I thought I knew it but now I am having second thoughts as my last adjustment does not seem to of solved my problems.

And just to be sure I need to measure pinion angle plus driveshaft angle as it hits the pinion and then add those to get the final angle?

-2 degrees?

Thank You
Mike
 
Trans and diff need to be within 1-2* of parallel. Measure the output yoke bearing cap, the driveshaft tube, and the diff flange. Front half should be within 1-2* of the rear half.

Assuming 1pc driveline?

Tremec actually has a cool Android app to use for angle checking as well.
 
I'd go even tighter than that, shoot for 1/2deg or so. If the car has rubber bushings on the trailing arms, you might want to nose it down a smidge as the pinion will rise under acceleration.
 
I'm with culberro on this. Also, I believe there is a MINIMUM u-joint working angle: the difference between the prop shaft and trans/differential housing. I THINK it's only 1?, but don't quote me.
 
I'm with culberro on this. Also, I believe there is a MINIMUM u-joint working angle: the difference between the prop shaft and trans/differential housing. I THINK it's only 1?, but don't quote me.
I remember from auto tech school that you need at least 1/2? of u-joint angle. If I remember right it's so that the bearings are always under a little load (so they don't just rattle around loose causing excessive wear). And up to 3? of angle before you get binding/vibration issues.
I'd aim for 1?.
 
I'd go for 0', if the rear travels up and down vertically. Check the angle at ride height.
 
2 piece driveline. The t5 trans mount is sad that the PO did and it has 1.5 deg pointing down ( that means positive deg right?) so I need to address that. The pinion itself is at a proper -2 right now. I think the car always had some minor issues because of the trans mount and with the rubber bushing it was not an issue but now with the solid bushing it is. Under accel I have no issues but on decel in 5th at certain rpms it sounds like either an exhaust hitting something or something esle. My exhaust seems to clear everything as it is a TME catback but I am trying to get it all figured out. When I first swapped the solid arms on I didn't measure properly and I had something like +3 at the pinion. And there were really odd things sometimes between shifts. With my latest adjustment almost all issues are gone except for the decel at certain rpms in different gears. Hopefully this weekend or next I can address the trans mount issue so the center shaft to support bearing is at zero and then see what happens.

I have the stock rubber bushings on the frame but the torque rods are solid now.

RearSubFrame9.jpg
 
I remember from auto tech school that you need at least 1/2? of u-joint angle. If I remember right it's so that the bearings are always under a little load (so they don't just rattle around loose causing excessive wear). And up to 3? of angle before you get binding/vibration issues.
I'd aim for 1?.

That theory has to do with a single angle.
This is about the difference between fron angle and rear angle.
 
That theory has to do with a single angle.
This is about the difference between fron angle and rear angle.

Yes, you need minimum motion of the needle bearings in the U-joint. Driveline experts want the needles to continue to "roll" a bit in operation, not motionless.

Angles need to be as close as possible to the same (trans output flange / pinion input flange).

Drag racers setup the rear for proper angle under full torque application.....not ideal for a street driven vehicle. I think Currie Enterprises has an excellent FAQ to explain this well.
 
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