Gear Vendors comes through, BIG TIME

[Musicman]

The vibration comes in at the same speed whether in overdrive or not.  Bob

I don't know the history behind this thread, but my first question would be, when was the last time you checked your tires & rims.
65 to 75 is a very common area for minor vibrations to show up and then suddenly disappear... especially with tires that have a couple of seasons on them. Would this be close to the speed range where you are experiencing this problem? Any uneven wear on the tread? Were the tires and rims originally balanced for "high speed" or standard balance, and are they still in balance front & Rear?...  Are all of your bearings, etc still tight? If it's happening at speed regardless of rpm, I wouldn't start looking at my drive shaft etc just yet... at least not until I had ruled out the usual list of demons first. But as I said, I don't know the history, so I am just stating the common as well as the obvious.

[RECHRGD]

Musicman, thanks for the comments.  All those bases have been covered and more.  I guess I should have not started a new thread and kept the comments in my old posts in the suspension and wheel area of the forum.  I just got back from taking the driveshaft to a different driveline shop to have it checked on his equipment.  He found a "slight" vibration up by the front yoke and fixed it by putting a small weight on about a 1/2 offset from the existing one.  He didn't think it would enough to cause a vibration in the drivetrain, but I'm sure hoping that's it.  That would have been the last thing on my mind after having TWO driveshafts built and balanced.  I'll throw it on tomorrow and let you guys know.  Bob

[RECHRGD]

Well, I put the driveshaft back on and it didn't change things much.  It may be a little better, but not much.  I played with the pinion angles AGAIN without much change.  I did start taping on a washer at various spots on the driveshaft and seemed to have some positive results.  The vibration seemed to calm down when I put the washer right over the top of the existing weight at the rear of the shaft.  I know I've gone through this same exercise at the first driveline shop and found no improvement.  I'm too tired to keep messing with it today, but tomorrow I will add another washer at the same spot and see what happens.  To be continued... Bob

[Sublime/Sixpack]

One thing I've had to do even after two different Driveline Shops built and balanced new driveshafts for me was balance the shaft in the car myself. I got fed up pissing around with professions not being able to get things smooth, so I bought a large adjustable clamp big enough to go around the driveshaft and with the rearend up on jack stands did it myself. I've had to do this on three of my cars through the years. The screw section of the clamp is sometimes heavy enough to put the shaft in balance once you find the right spot.

[RECHRGD]

One thing I've had to do even after two different Driveline Shops built and balanced new driveshafts for me was balance the shaft in the car myself. I got fed up pissing around with professions not being able to get things smooth, so I bought a large adjustable clamp big enough to go around the driveshaft and with the rearend up on jack stands did it myself. I've had to do this on three of my cars through the years. The screw section of the clamp is sometimes heavy enough to put the shaft in balance once you find the right spot.

Yep, I'm leaning that way now.  I did do the clamp thing, but maybe didn't play with it enough.  Just seems not right to have a driveshaft perfectly balanced by different shops and then start having to change the balance on the car.  Bob

[elacruze]

I think somewhere up the thread I mentioned that a friend of mine had a Moser forged pinion yoke (high-end brand-name part) which was so far out of balance that it made the driveline vibrate. I mean the yoke all by itself was something like 4.5 ounces heavier on one side. We balanced it on a lawn mower blade balancer, and the vibration went away. Of course since the pinion yoke was not part of the driveshaft assembly it wasn't included in the shaft balance.

Have you had your pinion yoke off to get balanced? Since it appears to be the pinion yoke end of the shaft that's affected, and it follows my personal experience, I'm strongly suggesting the pinion yoke is at fault.
Why it doesn't vibrate with the GV off, remains a mystery.

Eric

[RECHRGD]

Why it doesn't vibrate with the GV off, remains a mystery.

Eric
[/quote]

Yep!  I'm thinking that with the added weight and shorter driveshaft the whole dynamics of the drivetrain is thrown for a loop.  Bob

[RECHRGD]

Well, I've been playing with weights (washers) all day, taping them at different points on the driveshaft but haven't been able to find the sweet spot yet.  I can make it better or worse, but just can't kill the vibration.  Mike at GV wants me to use the hose clamps instead of taping on washers.  I'll try that over the weekend.  Bob

[b5blue]

Good Luck Bob! 

[RECHRGD]

Good Luck Bob! 

Thanks!  I'll need some luck with this thing.

[Sublime/Sixpack]

Mike at GV wants me to use the hose clamps instead of taping on washers.  I'll try that over the weekend.  Bob

Hose clamps as in plural? I'd suggest one big one like you'd find in the plumbing Dept. And maybe use a shiny new penny instead of a washer under it for good luck. 

[RECHRGD]

Hose clamps as in plural? I'd suggest one big one like you'd find in the plumbing Dept. And maybe use a shiny new penny instead of a washer under it for good luck. 
[/quote]

Yes the big ones so you just have the one little worm gear thingy to act as your weight.  I like the penny idea.

[Sublime/Sixpack]

I did mention the penny tongue in cheek but in all seriousness I do have one car that I did use a penny under the clamp screw as a weight. I used a ballpeen hammer to give it just the right amount of curve to fit the driveshaft then clamped it on. It's been there for years.

[RECHRGD]

I did mention the penny tongue in cheek but in all seriousness I do have one car that I did use a penny under the clamp screw as a weight. I used a ballpeen hammer to give it just the right amount of curve to fit the driveshaft then clamped it on. It's been there for years.

I'll probably need a silver dollar!

[RECHRGD]

FINALLY SUCCESS!!!!!!!  I went through the whole pipe clamp thing again, but methodically and with more patience than in the past.  In the end I had to find a spot at the front of the DS that seemed to show the most improvement.  I then added a penny and it improved a little more.  I went to the rear and went though the same scenario until IT HAPPENED, NO MORE VIBRATIONS.  I called GV to eat crow but Mike was just happy that it's finally resolved.  He was a little surprised that both the front and the rear had to be "adjusted".  I still don't now why I had to unbalance a perfectly balance DS to make it work.  Time for a scotch!  Bob

[tan top]

    you sorted it then , thats great to hear Bob   
good bit of detective work   
   

[Just 6T9 CHGR]

crikies!   how much change did you wind up using?

So the next step is to weld weights onto the shaft in those locations?

[The70RT]

Good deal Bob   

[RECHRGD]

crikies!   how much change did you wind up using?

So the next step is to weld weights onto the shaft in those locations?

I only used a penny up front.  The weight of the clamp adjuster screw seemed to be enough in back.  I may try a penny in back tomorrow just for the heck of it as there is still a tiny bit of vibes, but not enough that I think I would ever feel on the road.  I just hope the driveline guy can figure out the exact weight to weld on.  Bob

[firefighter3931]

FINALLY SUCCESS!!!!!!!  I went through the whole pipe clamp thing again, but methodically and with more patience than in the past.  In the end I had to find a spot at the front of the DS that seemed to show the most improvement.  I then added a penny and it improved a little more.  I went to the rear and went though the same scenario until IT HAPPENED, NO MORE VIBRATIONS.  I called GV to eat crow but Mike was just happy that it's finally resolved.  He was a little surprised that both the front and the rear had to be "adjusted".  I still don't now why I had to unbalance a perfectly balance DS to make it work.  Time for a scotch!  Bob

Right Fricken On !!!! 

So, it was the driveshaft afterall huh 

Glad you found it Bob 



Ron

[Sublime/Sixpack]

 

[elacruze]

Dynamic balance is weird science for sure.

Very happy to hear it resolved, and oh BTW what are you doing with those other GV length driveshafts?   
I need one myself and may need two, one for the D60 and one for the 8-3/4.


Eric

[8WHEELER]

    Way to hang in there Bob, you had so many other suggestions from
people trying to help, I just laid back reading your threads, and hoping you would find the problem
without another person ''me'' in the mix.

You will be more than happy driving that beautiful rig this year, with no vibration   

Dan

[RECHRGD]

Dynamic balance is weird science for sure.

Very happy to hear it resolved, and oh BTW what are you doing with those other GV length driveshafts?   
I need one myself and may need two, one for the D60 and one for the 8-3/4.


Eric

Eric, sorry, but I can't help you there.  When the driveline guy built the other driveshaft he kept the old one. He was not charging me because he thought it was his fault.  Bob

[elacruze]

Eric, sorry, but I can't help you there.  When the driveline guy built the other driveshaft he kept the old one. He was not charging me because he thought it was his fault.  Bob

That's a stand-up guy. Where is his shop? I'll have to get one made somewhere, and to my knowledge there are no reputable shops very close to me.