vibration

[Oldboy]

Yes yes,
This is making sense. Car is now in a garage/ work space. Going to order inclometer, and start fresh. Thanks for all the replies.
Will post asap
Russ

 

[Oldboy]

Hello,
This is a follow up, in progress from my earlier posts. Its already end of july. Been occupied with house move and other projects.
I purchased an inclometer, and have found that the transmission is angled down 6° , and the rear pinion angled down 2°. I am hoping to raise the transmission the appropriate amount. don't know if I will have the room.
incidentally the rear universal joint was wiped out. which is not surprising , and was also predicted by one of you guys.

 

[smallfoot]

Now that you have your inclinometer, go back to the carb base and start with that level. Most intake manifolds have the angle built in.....then adjust the rear pinion angle to the suggested 3 degrees. Speedway catalogs used to have speedy tips with this info...

 

[Oldboy]

Hello
I got the driveshaft back. Rear joint was shot. In the interim, i measured the angles. Rear angle is 2°down, trans angle is 6°down . no good. If i cannot get the trans to go up further any other options? Intake manifold is level.

 

[8literbeater]

Yikes! 8 degrees difference! Sam Fear has exactly what you need in post #15. I wouldn't bother with moving the trans. Just stick some 8 degree shims under the axle and you'll be fine. You can get 'em from Summit and probably many other places.
I've gone through a lot of driveshafts and vibrations, and I've cut and rewelded my share of spring perches. (see my 8literbeater build for example)
There's no reasonable way that 1.5 inches would require a change in driveshaft length. The slip yoke probably moved less than 1/8 inch.

 

[8literbeater]

When am I gonna use this math in the real world?

As a quick side note. From the motor mounts to the transmission mount should be about 36 inches. If you were to raise the rear of the transmission, you'd have to raise it 5 inches at the trans mount, to make up 8 degrees.

Correction: That would be for a TH350. For the 400 it's about 43 inches between mounts, and you'd have to raise it 6 inches to make 8 degrees!

 

[8literbeater]

Did you get it rolling smooth?

 

[Oldboy]

Follow up

Hello,
Well the car is back together. I think the vibration is gone. Took it out , for some 45/50mph driving. Seems good. Didnt wail on it as i wanted to tack the blocks to the perch and 6°the shims. Got that done, but also dumped the gas and changed out the fuel filter, as the car sat over 8 months.
will get it out this saturday. Was hoping to take it to a rat cruise upstate newyork, but didnt make it.
thankyou for all to those that helped. It now has trans 6° down, and axle pinion 6°up.
equal and opposite. Hope this works.