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(pinion angle) How to change my trans angle?

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Old 11-16-2015, 05:54 PM
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Originally Posted by TrendSetter
pinion angle is neither skinning cats nor rocket surgery. there are not opinions on this and its not that hard if you follow appropriate instructions.
Correct. Pinion angle is the difference between the angles of the rear end pinion and the driveshaft angle. And that's really it.
Old 11-16-2015, 06:19 PM
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Originally Posted by GMCtrk
Correct. Pinion angle is the difference between the angles of the rear end pinion and the driveshaft angle. And that's really it.
So in your opinion wish setup is better:

The way i used it for years pinion angle 5 degrees facing up, trans shaft facing 6 degrees down

Or now with the shims wish are secured with the bolt trough the middle hole and the u joints holding it on the sides so it cant move with the pinion angle 2.5 facing down and trans shaft 6 degrees facing down?
Old 11-16-2015, 07:51 PM
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The amount of pinion angle you put in will be more in line with what your doing. Track vehicles with leaf springs want more pinion angle than a truck you ride around on the street. Keep that in mind.
Old 11-16-2015, 08:03 PM
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Originally Posted by walledition
So in your opinion wish setup is better:

The way i used it for years pinion angle 5 degrees facing up, trans shaft facing 6 degrees down

Or now with the shims wish are secured with the bolt trough the middle hole and the u joints holding it on the sides so it cant move with the pinion angle 2.5 facing down and trans shaft 6 degrees facing down?
You haven't actually given me your pinion angle. What is the angle of your driveshaft?

My pinion angle is -2 but you definitely want it to be negative not positive. For track purposes, you have to assume that under power the pinion is going to rotate upwards. This can negatively impact your pinion angle if not accounted for. The goal should be to have an angle close to zero but not zero under max power to keep the ujoint happy and to transmit max power to the rear end.
Old 11-16-2015, 09:58 PM
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Originally Posted by GMCtrk
You haven't actually given me your pinion angle. What is the angle of your driveshaft?

My pinion angle is -2 but you definitely want it to be negative not positive. For track purposes, you have to assume that under power the pinion is going to rotate upwards. This can negatively impact your pinion angle if not accounted for. The goal should be to have an angle close to zero but not zero under max power to keep the ujoint happy and to transmit max power to the rear end.
Ok i went to measure the driveshaft and lets see if i can explain this correct:
-Im taking both picture from the passenger side
-the left side of the driveshaft (the side that connects to the rear end) is pointing down to the floor 2 degrees
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Old 11-16-2015, 10:25 PM
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Driveshaft angle was 0 before the shims
Old 11-16-2015, 10:33 PM
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That's way off, way too negative.

The rear end pinion needs to be shimmed upwards. Based on the DS angle of 2 degrees, I would put the pinion at 0 (parallel with ground).
Old 11-16-2015, 10:46 PM
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Originally Posted by GMCtrk
That's way off, way too negative.

The rear end pinion needs to be shimmed upwards. Based on the DS angle of 2 degrees, I would put the pinion at 0 (parallel with ground).
Can you tell me how u calculate that?
Old 11-17-2015, 06:42 AM
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Originally Posted by walledition
So your saying its ok that the transpinion points down 6 degrees and the pinion angle also points down but 2.5 degrees? i guees as long as it doesnt vibrate the rest is test 60s at the track and keep the one where the traccion is the best huh?
Is trans mounted stock?
My jeep trans is pointed down but my rear angle is up....the driveline angle is the key to no vibration


In racing you have to take into account axle wrap and thats where ppl refer to having pinion neg
Old 11-17-2015, 07:07 AM
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This is becoming a mess.

As George has said. Get the transmission mount to as close to the stock angle as possible.

Since you have a lowered truck, as you have experienced the rear angle will be the one that will be off.

If both are off, all you can do is be patient and get the transmission mount to where it can be functional and then go the rear and work there.

Like was already said about using your angle finder, pick a way and do the best you can and ask questions if your confused to that provider of instruction. Dont ask anyone else, your just making a mess if you do.

Good luck to you.


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