Although it sounds like a bent, damaged, or warped drive shaft, also check for looseness at the front driveshaft yoke.  A worn bushing at the rear of the transmission where the driveshaft yoke slips in can also contribute to what would be diagnosed as driveshaft vibration.

Lorena, Texas (South of Waco)

.030 is a lot of runout for a driveshaft, especially in the middle.  At speed it will tend to whip and run out even more.  Your local driveshaft shop should be able to help you.

John - "The Hoosier Hurricane"

Thanks for the help, I put it up on jack stands. The driveshaft has a little wobble to it. Maybe about .030th in the middle. The U joints seem pretty tight. I had changed the pinion seal so Iam sure the pinion nut is tight. I will get some new joints and have the shaft balanced. Thanks again I will let you know how it does after the shaft is done..Mark

WTB 1955 Courier emblems    Mark, Jefferson City Missouri

Hi Marv

Thanks for the links to this site. It certainly makes great reading.

It never ceases to amaze me what info is out there on websites. If we could find it all we would all be Supreme Beings- no pun intended for this site's Supreme Beings who I don't think we can ever catch up with.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

Check out this site for very good driveline info. Click on the link

http://www.iedls.com/

then click on the "education zone" at the top of the page then open up the trouble shooting guide. It gives lots on info on causes of driveline vibration.

marv

Ditto to what Hoosier and Aussiebill said or the shaft may be like the one on one of my cars.Not bent,but it had a dent in it.I had a machine shop pull the dent and got rid of about half my vibration.

 

Paul,

Boonville,MO

Do what john suggests and also pull and push on shaft looking for any movement at the joint areas AND check if the diff pinion nut it tight! These pinion flanges are often loose with oil leaks and vibrations the resulting symptons.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

Jack the car up and put jackstands under the rear axle.  Start the engine and put it in low gear.  Crawl under and look at the driveshaft.  It should run true, and if not, there is your problem.  Even if it runs true, it still could be out of balance.

John - "The Hoosier Hurricane"

Y-Guy "55"     Before you go to far, with this, it may be that the driveshaft

               is out of phase....Does your shaft have a removeable slip yoke?

               If so, and you had it apart, when you slip it back together make

               sure the u-joints are "in line" with each other. They must "work"

               together.(Sight down the shaft or lay in down on a flat surface,

               you'll see what I mean) Hope this helps........

                                               Bill

Bill

Pelham,Al

No, that is one thing I did not think about. Thanks...

WTB 1955 Courier emblems    Mark, Jefferson City Missouri