Optimum driveline angles for vibration free high speed operation.

[andrewb70]

12 bolt Moser, and forgot to mention...a T56 Transmission.

So I would shim the Pinion to / which would require a 3.5 degree shim, that would put my pinion / 2 degree's. That is my confusion, is the pinion considered a - or + from drivers side view currently \ ? That would clarify my mind on the opposing degree's of transmission yoke and pumpkin yoke cancelling each other out along with working angles.
Thanks for the response

Your set up is not unlike many others. There is actually a really good discussion here:

http://www.corner-carvers.com/forums...ad.php?t=49015

Currently your front operating angle is 3.5 degrees and the rear is 1.5 degrees. As you go under load the pinion rotates up and increases the amplitude of both the front and rear operating angle. This isn't optimal, but as I said before, many have this issue, including my GTO.

In the link above in post 32 there is this image:



I have never had much luck with the top configuration, but apparently it is also proper. If you read further in the c-c thread, you will see posts from Joe Birk. HIs ultimate solution was an ultra high speed balance from The Driveshaft Shop.

Andrew

[hifi875]

where is the proper spot to measure pinion angle? I have a 10 bolt 8.5 chevy. Can I measure it on the back where the bolts are or what?

[andrewb70]

where is the proper spot to measure pinion angle? I have a 10 bolt 8.5 chevy. Can I measure it on the back where the bolts are or what?

It is best to take the driveshaft off the pinion yoke and measure on the machined flat surface of the yoke.

Andrew

[icemanrd19]

How much of the shaft of the trans yoke do you all have sticking out? I have about a inch of the yoke shaft showing.

I still have that humming/ vibration in my driveline. Engine is 3.5 degrees, driveshaft goes down .5 degrees which creates a front operation angle of 3 degrees. To clairfy if i had a marble it would roll off the trans and down the driveshaft since they are both going downhill. The rear pinion is set at 2 degrees down which the same marble would then get stuck between the driveshaft and yoke since the driveshaft and yoke create a V. Rear operation angle would be 2.5 degrees. Front edge of pinion member to the beginning part of the rubber seal on the transmission the distance is 48 1/4" . strange i dont have any of that vibration or noise unless im going 75mph plus.

Already sent my specs to the driveshaft shop to possible go with a CV joint driveshaft. I literally have my trans 1/8" from the floor by the shifter bolts and i already raised the floor. I can either raise the floor a 1/4" to gain more clearance and raise the trans up some more to get to 3 degrees but its quicker to just get a CV driveshaft.

[downl50]

Great thread, learned a lot so far. Question is about an A body setup (70 Chevelle). Has anyone gotten the motor/tranny (small block/T56) close to parallel without major tunnel modifications? I already have the tunnel patch welded in and have the motor/tranny at stock 3 deg down -- would love tips on getting it flattened out if it doesn't require more metal work.

Thanks

[andrewb70]

Great thread, learned a lot so far. Question is about an A body setup (70 Chevelle). Has anyone gotten the motor/tranny (small block/T56) close to parallel without major tunnel modifications? I already have the tunnel patch welded in and have the motor/tranny at stock 3 deg down -- would love tips on getting it flattened out if it doesn't require more metal work.



Thanks

First thing to check is if any of your front accessories will hit anything if the back of the engine is raised higher.

Andrew

[icemanrd19]

How much of the shaft of the trans yoke do you all have sticking out? I have about a inch of the yoke shaft showing.

I still have that humming/ vibration in my driveline. Engine is 3.5 degrees, driveshaft goes down .5 degrees which creates a front operation angle of 3 degrees. To clairfy if i had a marble it would roll off the trans and down the driveshaft since they are both going downhill. The rear pinion is set at 2 degrees down which the same marble would then get stuck between the driveshaft and yoke since the driveshaft and yoke create a V. Rear operation angle would be 2.5 degrees. Front edge of pinion member to the beginning part of the rubber seal on the transmission the distance is 48 1/4" . strange i dont have any of that vibration or noise unless im going 75mph plus.

Already sent my specs to the driveshaft shop to possible go with a CV joint driveshaft. I literally have my trans 1/8" from the floor by the shifter bolts and i already raised the floor. I can either raise the floor a 1/4" to gain more clearance and raise the trans up some more to get to 3 degrees but its quicker to just get a CV driveshaft.

So I ordered a new driveshaft from the driveshaft shop. They suggested a 3" or a 3 1/2 reg aluminum driveshaft. I went with a 3 1/2 aluminum with a inner vibration reducer and it fixed all my issues. Light throttle rumbling and 70mph up to 120 plus vibration. Talk about night and day difference