Help vibrations

[Peter]

I am having a big problem with vibrations, I think it comes from the driveshaft or something in this area. I have tried the following.
Pinion angel set up and down are now at front 2 degree down, rear axel 2.5 degree down and driveshaft 1 degree down rear.
The driveshaft has been fully balanced and is straight and with new u-joint. I have tried two different complete rearaksel carrier.
The vibration is coming at around 4000 RPM in high gear (TH700 with lock up) and getting worse when I goes higher in RPM. The rear is 3,89-1. and the car is a 69 Camaro take a look at http://www.pro-touring.dk

Thanks Peter

[sinned]

You have already discovered your problem....the pinion and powertrain cannot both angle down. If the powertrain is set to 2.5* down than the pinion has to be at least 2* up. That will take care of your condition.

BTW, see this thread...we just had this discussion a week ago.

[Peter]

Hi Denny

Thanks for your answer, but there are somthing that I dont understand, I have bought a book How to build & modify GM Pro-touring Street machines. In this book there are pictures and explanation these word are from this book
Engine and transmission tilted 3 degrees down, pinion angel is equal to transmission angel 3 degrees down. Notice the pinion and transmission angel are both down.
Please explain because now I am confused!

Thanks, Peter

[907rs]

Peter, the angle of the pinion vs. the angle of the trans output shaft should be equal, but opposite; meaning they both have the same angle, but the pinion is pointed up and the output shaft is pointed down.

[sinned]

Originally Posted by Peter

Hi Denny

Thanks for your answer, but there are somthing that I dont understand, I have bought a book How to build & modify GM Pro-touring Street machines. In this book there are pictures and explanation these word are from this book
Engine and transmission tilted 3 degrees down, pinion angel is equal to transmission angel 3 degrees down. Notice the pinion and transmission angel are both down.
Please explain because now I am confused!

Thanks, Peter

Don't be confused Peter, if you saw in print that the pinion and trans should both point down it was obviously a typo. I have spoken with Tony several times, he is a pretty bright guy. He is currently working a new "version" of the book to correct some typos from publishing.

Reset your pinion to point up a few degress and you vibration will go away.

[Peter]

Hi there,

Now I am getting it, I will try to put wedges between my rear end the spring to get the angel up.
I will be back soon with the result.

Thanks for the advice.

Peter.

[Peter]

I have now put my pinion angle to the following specifications: Trans output 2 degrees down, drive shaft 1 degree up, and rear end 2 degrees up. In this way I will have 3 degrees working angle front and 3 degrees working angle back and they are opposite.
But…….. The vibrations are still there. I feel no difference it is still like the vibrations is coming from the drive shaft or the u-joint.
Any other suggestions to this problem, I will do anything to get these vibrations away.

Peter