Adjusting pinion angle...please confirm I am on the right path...

[908ssp]

From the sounds of things, based on Kelly @ BMR and others, post #2 is incorrect. Please disregard this post.

I guess I can go back and readjust mine correctly now

Does it vibrate? If not leave it alone.

 

[tmcolegr]

Does it vibrate? If not leave it alone.

No vibrations

 

[BMR Tech]

From the sounds of things, based on Kelly @ BMR and others, post #2 is incorrect. Please disregard this post.

I guess I can go back and readjust mine correctly now

If your set-up works, then it is fine sir.

I agree 100% with your method, for working angles.

It will provide a slight difference, on two exact combos.....BUT, you probably agree...it is all a "guess"

If someone can go say, 120 MPH without a single Vibration....who cares what the angles are, right?

People commonly seem to over complicate pinion angle.

One thing is a fact. with U-Joints, you want the "planes" to be parallel to each other. (drivetrain/crankshaft angle.....and pinion flange angle) while the drivetrain is under load. (0 degree angle difference)

On just about any other combo, the "technically correct" way to achieve proper pinion angle is by comparing the working angles, especially on a 2-piece shaft.



For customers with a 1-piece shaft, I try to simplify it for them. Measure the drive train angle, then place the angle finder on the pinion flange and it needs to move two degrees to the "right" on the gauge. (assuming measurement from the driver side) This ensures you have the pinion down in relation to the drive train, without adding, subtracting, and confusing themselves with positive and negative angles on different planes.

As for angles, since we use high durometer poly on our parts, I typically recommend the pinion flange be about 1.5 degrees lower than the drive train.

For spherical bearing parts, .5 - 1 degree lower.

 

[Pumpkinfish]

Kelly,

Can you post a picture of what you are talking about? I am so confused at this point plus I am a visual learner. What I am gathering from your posts is that I want to start with the trans pointing down and the pinion flange pointing up at the same angle (positive and negative are irrelavant at this point). Once that is acheived, I want to make the pinion flange go towards the ground 1.5 degrees from the previously measured angle which would be by making your UCA longer. Is that correct? Also, I looked at the directions Coast sent with thier driveshaft and they say to set the pionion angle to the same as the trans while at ride height and that is it (they claim the transmission flange from the factory is 2.7 degrees down).

 

[J2L06GT]

Kelly,

Can you post a picture of what you are talking about? I am so confused at this point plus I am a visual learner. What I am gathering from your posts is that I want to start with the trans pointing down and the pinion flange pointing up at the same angle (positive and negative are irrelavant at this point). Once that is acheived, I want to make the pinion flange go towards the ground 1.5 degrees from the previously measured angle which would be by making your UCA longer. Is that correct? Also, I looked at the directions Coast sent with thier driveshaft and they say to set the pionion angle to the same as the trans while at ride height and that is it (they claim the transmission flange from the factory is 2.7 degrees down).

You want to make the UCA shorter to move the pinion flange towards
the ground, everything else looks correct. Pinion will twist up under
load and Trans-Shaft-Pinion will be in straight line.
I have a Spydershaft and the first on I got was'nt straight and had
vibe, the way I found problem was to support rear axle and ran in
gear and saw wobble in shaft.

 

[gil_t2]

when you lengthen the UCA you are rotating the pinion UP , when you shorten it the pinion it moves down, Remember that the pivot point is the axle. You do not want the pinion pointing at the trans, you want it pointing a little below. I do not want you to be more confused, but the reason they can't be at same angle is the wheel base. The flanges can be at the same angles, but that does not equate to them lining up. So your trans points down 2.5 so your pinion should point up 0.5 that gives you a 2.0 difference. you can run 1.5 diff if you want.

 

[tmcolegr]

This morning I raised the vehicle, supported by the tires and level, and readjusted the pinion angle. The pinion flange angle is now 1.7* lower than the transmission output flange angle.

 

[13726548]

This morning I raised the vehicle, supported by the tires and level, and readjusted the pinion angle. The pinion flange angle is now 1.7* lower than the transmission output flange angle.

How did you elevate the car like that? Drive up on the ramps on the rear tires and jack up the front?

 

[tmcolegr]

I never drive up on ramps. I raise the vehicle with a floor jack and then only use the ramps to support the stationary weight of the vehicle.

 

[Pumpkinfish]

I never drive up on ramps. I raise the vehicle with a floor jack and then only use the ramps to support the stationary weight of the vehicle.

+1 That is how I did mine. I need to get better ramps. I had rhino ramps but I barely fit under the car. Is there different heights to ramps? If so where can I buy the tallest? I need to reinstall my watts link at some point and the car needs to be at ride height to get the geometery right. I know I am not going to be able to install that with the car on those rhino ramps!

My car is at the shop getting a trans seal reaplaced so I am taking a break from the pinion angle adjustments. While I am waiting, where is the best place to get a digital angle finder? I went to my Lowe's and Homie Depot and neither had one. Hell I'll go to Harbor Freight if they have one!

 

[gil_t2]

I got mine at a Wood craft tool store, I bought one called Angle box. it has magnets on the side for adjusting saw blades on table saws.