unfixable shake...

[PTS]

I just reviewed your video and from what I can see is that your pinon angle is to far up towards the floor pan. What I would do and they are inexpensive is go to a driveline shop or 4wd shop and get some pinon shims maybe a 2.5 degree and get the pinion pointed towards the ground. Measure the width of your springs so that you get the correct width shim. Shim goes in between leaf spring and spring pad on the housing...

Perry
PTS

[PTS]

Does the vibration feel worse under acceleration?

[SS PUNISHER]

I had a real bad shake in my caddy the other day, thought a wheel was fallin off!!! Turn out it was the front drivers side shoes were draggin bad, Idk why they got hung up but after loosening the adjuster and cleanin off the glaze it was good as new!

[SS PUNISHER]

i see you bfg's, Every set I've had (3) the belts seperated! Maybe that's just my bad luck....

[Hunter68]

i dont feel it under acceleration but i was thinking the same thing with the angle being wrong once i measured it but i couldnt actually figure out if it was right, but you think a 2.5 shim will do the job?

[andrewb70]

The way you measured the driveline angles is less than precise. Furthermore, you need to check the front because the front and rear working angles need to be the same.

Also, if you are describing this as a "shake" I would think that it is related to something that is turning at the speed of the tires and not the driveshaft.

Andrew

[Hunter68]

thats why i asked on how to do it but no one else had responded

[Hunter68]

does anyone know of where i can get cheap shims? there is only a difference of one degree but on summit its like 70 for set of six but is there anything that is cheaper or can be made?

[BADDRIDE II]

I agre with Andrew that most likely it is not drivetrain, but just to clarify driveshaft checklist......If I understood your video correct......your engine/tranny angle is at -1 degree tilted down, and your rear pinion angle is +1 degree tilted upward? If this is so.......it is not bad.......but under load/accelleration your pinion angle will want to increase (upward) by 2-3 degrees with a leaf spring type rear suspension (unless you run traction bars such as Cal-Tracs or similar-if you do you can pre load these to limit pinion movement to as little as 1 degree) So basically to obtain the best shaft angle under load/accelleration assuming you have a leaf spring type suspension....I would stick a 2 degree shim in which now should point your pinion down -1 degree so that under load you are at 0.
As for a quick wheel/tire troubleshoot..........try switching front wheels/tires to the rear (if sizing permits) and see if vibration changes at all......if it does you most likely do have a wheel/tire issue?
May sound stupid but have you checked your u-joints lately? Hope this has helped.

[Garymac69]

I had vibration problems on my '69 that took me years to solve. I ended up replacing most of the drivetrain and still had vibrations. I created a word document from many many hours of Google searches on the subject. My problem ended up being a combination of problems: original driveshaft that was "sprung" ie. a shop would straighten it and it would relax back to it's bent position in a few hours (bought a new driveshaft) and I also had a spread yoke on the input of my 12-bolt. When I replaced that, I finally cured my problems.

Gary