Bad vibrations...

[Dave145]

Does anybody know offhand how much it costs to get a new driveshaft made? Or how much to convert my existing shaft over to the conventional u joint shaft?

This week I may call around, but hoping to get an idea of how much I may be looking at.

 

[Centerline]

Interesting about the ziebarted driveshaft...kinda makes me laugh a bit.

The trans is flat or slightly pointed down, and the pinion is also flat or slightly pointed up.

The rear springs are weak, but the car sits level driving down the road so I'm told (I've had someone follow me around and watch the car drive).

Sounds as your pinion angle isn't out of the norm, however if your springs are weak it can cause the pinion to be higher than the trans output shaft or excessive spring wrap under acceleration which will change the angle enough to exacerbate the problem.

With the car on the ground measure the angle of the driveshaft. This will tell you if the pinion is higher or lower than the trans output shaft. If its higher then the weak springs are most likely the problem. Vibration on acceleration only is a classic symptom of this and you may need to add a shim to the axles and adjust the pinion angle down a couple degrees to make up for the weak springs if that's the case. Or add air shocks.. your choice.

This is probably redundant but... after you measure the trans output angle and the pinion shaft angle and you compare them, they should be equal and opposite. Then subtract the angle of the driveshaft from those two angles. The result should be less than 5 degrees. If its more than that you're stressing the "U" joint which can cause the vibration, not to mention early failure.

Also proper torque for the rear "U" joint cap bolts is 17-20 ft. lbs. Anything more than that will put the "U" joint bearings in a bind which will cause premature failure and could also contribute to your vibrations.

Good luck.

 

[wilmacmike]

Sounds as your pinion angle isn't out of the norm, however if your springs are weak it can cause the pinion to be higher than the trans output shaft or excessive spring wrap under acceleration which will change the angle enough to exacerbate the problem.

With the car on the ground measure the angle of the driveshaft. This will tell you if the pinion is higher or lower than the trans output shaft. If its higher then the weak springs are most likely the problem. Vibration on acceleration only is a classic symptom of this and you may need to add a shim to the axles and adjust the pinion angle down a couple degrees to make up for the weak springs if that's the case. Or add air shocks.. your choice.

This is probably redundant but... after you measure the trans output angle and the pinion shaft angle and you compare them, they should be equal and opposite. Then subtract the angle of the driveshaft from those two angles. The result should be less than 5 degrees. If its more than that you're stressing the "U" joint which can cause the vibration, not to mention early failure.

Also proper torque for the rear "U" joint cap bolts is 17-20 ft. lbs. Anything more than that will put the "U" joint bearings in a bind which will cause premature failure and could also contribute to your vibrations.

Good luck.

I know you have tried everything and you are still pulling your hair out. Years ago I had the same problem with a 1964 Polara I had bought from a fella.

The vibration was no different than yours. It took me quite awhile to figure it out. One day while at a car show in the Bay Area I ran into the previous owner of my car. I had no contact with him for several months after purchasing the car (did not know him before).

Anyway, I just happened to ask him if he experienced the same vibration I had going on. He actually apologized to me that he did not disclose to me during the purchase that he had run up a curb and took out a very small tree. He replaced the front bumper, part of the grille, AND the damaged rear right wheel.

When I got home, I put the back of the car up on jackstands, and ran it up to speed. Guess what I found? The replacement right rear wheel/tire were rotating in a slight elliptical motion.

It was moving up and down more than a badly mounted (centered) tire. I found the right rear axle to be slightly bent. Once replaced ALL of the vibration was gone.

It might be a long shot, but I would remove your rear wheels and rotate each axle by hand while measuring each and every mounting stud on the drums/hubs from the floor and make sure they are moving in a correct circle.

But I would also look very closely at the drive shaft as has been already mentioned.

Good luck with your problem and be blessed...

God Bless America,

Mike

 

[miller]

Does anybody know offhand how much it costs to get a new driveshaft made? Or how much to convert my existing shaft over to the conventional u joint shaft?

Probably don't need a new driveshaft, unless your's is bent. But, balancing could be checked, along with the joints. Driveshaft shop would need an adapter plate (which they should have) to mount up the front flange.
Even if all is original, for the rear u-joint yoke, you should measure the u-joint seats, to see if they are the same. That will tell you what u-joint to use.
To convert one, to take a slip-type front yoke, at the very least, the trans rear housing, and shaft would have to be changed. If not, the whole trans, to a later year.

 

[Glenwood]

Here's a place in Texas that does a conversion for B&T. I think you can also order one from Mancini.
http://www.driveshaftspecialist.com/Left-Column/Antique-Classics.html

I found a place local to me that does them as well for around $500. I'm sure there are places in your state that does them.

 

[pushrod]

Carolina Driveline built a new chromally shaft for my 64 Belvedere for $275. Works perfect. Between the tire issue and drive line sound like a bent axle or the spring issue. As stated weak shocks will compound the issue. I would spend$50 bucks on KYBs and eliminate that part of the equation. That may better allow you to diagnose the issue. It is frustrating but hang in it will be something simple.

 

[Dave145]

Through a very in-depth Google search, I found the parts I need to convert the driveshaft over to a regular u joint. I've also seen a site that advertised they could build a new shaft for $385 + shipping.

Unfortunately, that's a long shot out of my budget and just not feasible. May try a new u joint a see if that helps or try a different thickness clip kit to better hold it in place.

 

[coloradodave]

Yes it was the correct joint. Measured it against the old one when I purchased it.

From your post #50: "The car vibrated terribly when I bought it too." Don't want to be mean but measuring it against the old one, when the car had a vibration with the old one, doesn't help the situation in trying to eliminate causes of the problem...
BTW, the only reason to go through the hassle of replacing the transmission main shaft and the driveshaft to get rid of the B&T joint is if you just don't like looking at it. I run one in my car, and yes, it's ugly, but it's very strong and trouble free.

 

[Dave145]

I checked up and down with every store in town and there is only one size u joint available for my car. I happened to have a second one laying around, so I decided to swap it out.

I also decided to have another look at the B&T joint. Everything was in order, except for the torn boot. I've known it was torn for awhile now, but thought I'd replace it later. Decided to cut it off tonight, and found the top half partially sucked up into the cup that holds that joint. I'll be getting a replacement boot tomorrow for it and installing it later. Pulled the balls and rollers off again, cleaned them up and reassembled with lots of grease. No signs of extreme wear on anything. The cup slides felt fine, the balls were not gouged, etc. The centering springs for the end pins were flat, so I rearched them a bit and filled the hole with grease to help force them out better (while still allowing them to move inward).

Hope to get the shaft back in the car tomorrow after a final look over. Checked shaft for straightness with a Carpenters square and it is fine all the way across.

Unless I'm missing something, certainly looks like the driveshaft checks out ok, with the exception of it possibly being out of balance (which I kind of doubt because the only weight on the shaft is still present and there doesn't appear like any others were ever attached).

Pinion does not move up and down when I try to shake it by hand, and the output shaft doesn't either.

 

[Dave145]

Well I got the shaft back in the car. New boot from O'Reilly went right on. Bolted everything up and greased the ujoint last night. Hoping to do shocks next week or this weekend just for peace of mind. If that still doesn't solve the problem, I'm not sure what to do.

 

[Dave145]

Well that wasn't it. Problem is worse. Symptoms:

10-25: good
30-50: earthquake. Felt in wheel, dash, floor, seat. Changes mirror positions.
55-65: nice and smooth
70+: easy now cowboy! Buckin bronco coming through! Rear end hops like a rabbit from the feel of it. Kind of a "whumo whump whump" feeling that gets worse with speed.

I'm stumped. My forehead is flat as a board, and I have lasting brain damage from smacking the wall. Measured angles. Rebuilt front end. Dicked with the motor to make it run like a sewing machine.

What now? Call the priest? New rear end? Replace the seemingly good shaft? Burn it?

My wallet hurts. Time to call it a night.

 

[miller]

Well that wasn't it. Problem is worse.

It's loads of fun, chasing your tail, ain't it!
Sorry, don't mean to make light, of a problem like your having. First thing I'd suggest, is deal with the known...get new shocks on it...all four, and be done with that. Bad shocks only adds to problems like that. Could be a big part of it.

Just for kicks, any chance of a photo, of your rear u-joint? Maybe one of us can spot anything on it, and tell you, one way, or the other.

'Something' is making that vibration. Just have to pick it out.

 

[Glenwood]

Well that wasn't it. Problem is worse. Symptoms:

10-25: good
30-50: earthquake. Felt in wheel, dash, floor, seat. Changes mirror positions.
55-65: nice and smooth
70+: easy now cowboy! Buckin bronco coming through! Rear end hops like a rabbit from the feel of it. Kind of a "whumo whump whump" feeling that gets worse with speed.

I'm stumped. My forehead is flat as a board, and I have lasting brain damage from smacking the wall. Measured angles. Rebuilt front end. Dicked with the motor to make it run like a sewing machine.

What now? Call the priest? New rear end? Replace the seemingly good shaft? Burn it?

My wallet hurts. Time to call it a night.

Sorry this is being such a pita, but I like your sense of humour about it all!

 

[khryslerkid]

Decided to cut it off tonight, and found the top half partially sucked up into the cup that holds that joint.

The original boot is made that way to keep the grease in the housing.

New boot from O'Reilly went right on.

What boot did you get at O'Reilly?

Have you ever checked out the rear wheels and axels for running true. (Sorry if you've mentioned this but the thread is a little lengthy)

 

[Ski 61701]

Dave 145, I have a good ball and trunion driveshaft you can have it. The shaft came out of a 64 Dodge Polara 2dr.
All you have to do is come down and get it, not sure how far Bloomington Illinois is from you. But it might help save your sanity. Also messed up shocks will cause you grief.

 

[PP1RT]

Just put the damn shocks on already!!!

 

[moparman400]

i would inspect the flex plate and converter.

 

[747mopar]

I know you have tried everything and you are still pulling your hair out. Years ago I had the same problem with a 1964 Polara I had bought from a fella.

The vibration was no different than yours. It took me quite awhile to figure it out. One day while at a car show in the Bay Area I ran into the previous owner of my car. I had no contact with him for several months after purchasing the car (did not know him before).

Anyway, I just happened to ask him if he experienced the same vibration I had going on. He actually apologized to me that he did not disclose to me during the purchase that he had run up a curb and took out a very small tree. He replaced the front bumper, part of the grille, AND the damaged rear right wheel.

When I got home, I put the back of the car up on jackstands, and ran it up to speed. Guess what I found? The replacement right rear wheel/tire were rotating in a slight elliptical motion.

It was moving up and down more than a badly mounted (centered) tire. I found the right rear axle to be slightly bent. Once replaced ALL of the vibration was gone.

It might be a long shot, but I would remove your rear wheels and rotate each axle by hand while measuring each and every mounting stud on the drums/hubs from the floor and make sure they are moving in a correct circle.

But I would also look very closely at the drive shaft as has been already mentioned.

Good luck with your problem and be blessed...

God Bless America,

Mike

Borrow a dial indicator, to hard to measure accurately from the ground where a slight degree in rotation will throw you off.

 

[Dave145]

Well, looks like it's not the driveline. Removed the driveshaft tonight and ran the car up to 80mph in gear on stands. The car vibrates TERRIBLY all throughout the car now.

My guess is it's either the

Harmonic balancer (though my timing marks are dead on)

-or-

Torque Converter

I'd like to wish it was motor mounts, but they appear to be fine.

 

[khryslerkid]

Well, looks like it's not the driveline. Removed the driveshaft tonight and ran the car up to 80mph in gear on stands. The car vibrates TERRIBLY all throughout the car now.

My guess is it's either the

Harmonic balancer (though my timing marks are dead on)

-or-

Torque Converter

I'd like to wish it was motor mounts, but they appear to be fine.

You're saying you ran the car up to 80 without the driveshaft installed?