moosestang

Well there is some controversy on wether you should be using the driveshaft or transmission angle to set pinion angle for a 1 piece driveshaft. I've been researching it on the net and it seems most drag race oriented websites recommend using the driveshaft, while hotrod and street car websites will recommend using the transmission. (drag racers want the driveshaft and pinion to be inline during launch for the most power to the ground, makes since to me).

I used the transmission myself, but I also tried setting the pinion 2 degrees down in relation to the driveshaft angle and that gives me an annoying vibration at 2500rpms. (not shaking the mirrors vibration, but the kind that will make your head explode)

I've also read that instead of using the transmission flange (which is hard to get a reading from with the driveshaft attached), you can measure the angle of the crank pulley and set the pinion angle based on that. I took the liberty of measuring it today and this seems to be accurate and it should be since the crank and transmission output shaft should be inline with each other. Anyone else set their pinion angle using the crank pulley? My crank pulley looks to be 3 degrees positive (angled upward) which would be right since I measured my transmission flange and got 3 degrees negative.

When I go to the track I plan to add -1 degree to the pinion angle just in case it helps.

Vcoat

I just had my Denny's D/S installed and the mechanic claimed the pinion angle should not have changed. The carseems to drive fine!....so i guess hes right.

moosestang

Well he's right, the angle of the pinion doesn't change, but the angle between the pinion and driveshaft does and the factory pinion angle was setup for a two piece driveshaft that uses a CV joint, not a 1 piece that uses U-joints.

Don't expect your mechanic to know everything, he probably has better things to do than study up on his driveline geometry.

Do me a favor and run it up to about 5k in 3rd gear (slowly) and let us know if you hear or feel any strange vibrations.

jrm1900

Just guessing here but years ago I had a vibration problem with a Thunderbird SC that turned out to be a unbalanced driveshaft, that could be another posibility.
I hope you fix your problem and keepus posted as I also have a one piece aluminum driveshaft ready to install over the weekend.

moosestang

I don't have a problem.

zkiller

I have the PH driveshaft with an automatic transmission.
I have stock upper and lower control arms and my car does not vibrate at up to 165 MPH. Why would I change the pinion angle, unless there was a vibration?

Vcoat

As soon as this rain stops i will take it up to 5K in 3rdand let you know for sure!

Cyberwolf1986

Mine Does have this Vibration i got a D/S 3"one piecesteel driveshaft and its driving me nuts. I just have to tell my mechanic the pinion angle is off?

moosestang

When does it vibrate? A vibration caused by pinion angle and a vibration caused by improper balance are not easy to distinguish between. Of course if try every pinion angle possible and still get vibrations then you have your answer.

moosestang

well there are other things to consider like the working angles of your U-joints. If there is two much angle or not enough angle it can cause premature wear. You should be fine though.

It's also possible you have a vibration and don't feel it. Aluminum dampens vibration better than steel and carbon fiber is even better. If you don't feel it, it can still cause problems.

165? Was that down hill?