Highway speed vibration ('57 Thunderbird)

[yblock57]

Getting a bad vibration starting around 55 mph that gets worse up to 65 then gets less intense at 70+, but still there. Very annoying. Feel it in the seat, steering wheel — whole car. Tires are 4 yr old B.F. Goodrich Silvertown bias-plys. Just had all 4 rebalanced. Rims are true. Tires didn't show any signs of trouble on the machine. Run the exact same tire on the '57 Fairlane with no issues, so doubting that's the trouble.

Replaced:
— shocks
— universal joints
— trans mount
— engine steady rests

Driveshaft does not have any weights. Would y'all have that checked next? Being so short I didn't think that would be an issue, but I want to get this thing cruising smooth. Car has not been on an alignment rack in over 40 years, but nothing has been changed/messed with in the front end. Could use A-arm bushings. Wheel is off center but doesn't pull. Very few miles put on it until recently.

Thoughts?

[dmsfrr]

Originally Posted by yblock57

. . . Run the exact same tire on the '57 Fairlane with no issues . . .
. . .Car has not been on an alignment rack in over 40 years, but nothing has been changed/messed with in the front end. Could use A-arm bushings. Wheel is off center but doesn't pull. Very few miles put on it until recently.
Thoughts?

Have you tried swapping the T-Bird tires and wheels with the ones from the Fairlane? That will tell you if the shaking problem stays with the car or the tires/wheels.

The T-Bird steering wheel, steering column and steering box shaft all have keyed wide splines so they only fit together one way, and should be in the "straight-ahead" position.

Because the steering wheel is off-center something underneath needs attention and could be the source of the vibration.
Worn or dried out A-arm bushings aren't helping.

Might be time to find a good friendly front-end / alignment shop.
.

[Brian54]

I am experiencing the same issues with my 1954 Victoria ; hopefully, someone else has and found a solution to the problem . All feedback will be welcome .

[yblock57]

Originally Posted by dmsfrr

Have you tried swapping the T-Bird tires and wheels with the ones from the Fairlane? That will tell you if the shaking problem stays with the car or the tires/wheels.

IIRC the T-Bird steering wheel, steering column and steering box shaft each have keyed wide splines so they only fit together one way, and should be in the "straight-ahead" position.

Because the steering wheel is off-center something underneath needs attention and could be the source of the vibration.
Worn or dried out A-arm bushings aren't helping.

Might be time to find a good friendly front-end / alignment shop.
.

Took the words right outa my mouth. Will swap wheels with the fairlane and see if that changes anything.

Also will do some more poking around on the front end and see what else needs replacing. Anticipating a lot.

Wasn't aware of the keyed splines on the wheel/column/box. Could the off-center wheel be due to tie-rod ends being out of adjustment?

[CSPIDY]

I have the same issue on my 57 Tbird, same speeds, same tires, I have wire wheels and have isolated it to a bad wheel.
those BF Goodrich Silvertown tires seem to look like a snake when they rotate, not a big fan.

[dmsfrr]

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Originally Posted by yblock57

. . Could the off-center wheel be due to tie-rod ends being out of adjustment?

Yes, to re-center the steering wheel make one tie-rod slightly shorter and the other the same amount longer, while keeping the correct overall amount of toe-in. (approx 1/16 to 1/8 inch)
If the front end is shaking other repairs will be needed.
.

[wellcraft17]

Check the balance of your brake drums if they are original, they came from the factory unbalanced. Old school bubble balancer is the best way to check.

[dmsfrr]

Originally Posted by CSPIDY

I have the same issue on my 57 Tbird, same speeds, same tires, I have wire wheels and have isolated it to a bad wheel.
those BF Goodrich Silvertown tires seem to look like a snake when they rotate, not a big fan.

yblock57, here's a quick & dirty DIY way to ballpark check the wheels and tires for any wobble or out-of-round.

One at a time lift each one slightly off the ground in a well lit area. Place a bucket or similar item next to the wheel or tire with a length of wood or metal across the top. Place one end of it very close to an edge or tread surface of the wheel or tire and spin the tire/wheel fairly slowly by hand.
Look closely at the gap while spinning the tire/wheel and you'll be able to see any irregularity.

[ponymare]

It could be the bushing in the tail housing is worn also.

[yblock57]

I’ll definitely test the run out on the wheels.

I just replaced the tail shaft bushing due to excessive play/leaking fluid. Forgot to mention that.

Appreciate the help.

[Daves55Sedan]

Originally Posted by yblock57

I just replaced the tail shaft bushing due to excessive play/leaking fluid.

Do you know for sure that the driveshaft is original and/or has not been abused? It should have counterbalance weight(s) near the front. If not I would be suspect. How much of a gap is there between the front of the yoke and back of the rear extension housing. If the yoke is sticking out too far, and the driveshaft is out of balance, you will definitely have rear bushing wear and driveshaft wobbling.
If control arm bushings are really bad allowing movement between pin and control arm, those may cause alignment problems which could transmit to high speed vibration if front-end alignment is a little off.
Suggest looking at steering idler arm for excessive free-play too.

[yblock57]

Originally Posted by Daves55Sedan

Do you know for sure that the driveshaft is original and/or has not been abused? It should have counterbalance weight(s) near the front. If not I would be suspect. How much of a gap is there between the front of the yoke and back of the rear extension housing. If the yoke is sticking out too far, and the driveshaft is out of balance, you will definitely have rear bushing wear and driveshaft wobbling.
If control arm bushings are really bad allowing movement between pin and control arm, those may cause alignment problems which could transmit to high speed vibration if front-end alignment is a little off.
Suggest looking at steering idler arm for excessive free-play too.

Nothing's really for sure, but we had a reputable driveshaft shop check it out and install Spicer universal joints. If something had been out of wack, I would 'hope' it would've been caught then. Again, just going off what Dad told me.

The transmission was recently rebuilt and the rebuilder did not replace the output shaft bushing. Not sure if that's something they normally check anyway. We pulled it out for a bench job due to the excessive labor costs of pulling the engine to get the trans out. Only reason I noticed it, was the new seal leaking that upon further investigation showed some slack in the yoke. Bushing appeared to be original. Yoke surface is fine with no grooves. New bushing remedied the slack so at least that's one less thing on the list.

I have not measured yoke engagement, but will do when i get the car back up on stands. From what I recall it's in there pretty deep. Was checking a lot when the bushing was replaced feeling for slack. There are definitely no weights anywhere on the driveshaft.

[KULTULZ]

... those BF Goodrich Silvertown tires seem to look like a snake when they rotate, not a big fan

While you have it on stands, look for COUNTRY OF ORIGIN on the sidewalls.

If a man sectioned the AT out of a BIRD to rebuild it and did not replace the rear bushing as a matter-of-fact, it is hard to say what you will find.

[yblock57]

Originally Posted by KULTULZ

While you have it on stands, look for COUNTRY OF ORIGIN on the sidewalls.

If a man sectioned the AT out of a BIRD to rebuild it and did not replace the rear bushing as a matter-of-fact, it is hard to say what you will find.

Ha. Good point. The fordomatic debacle was a whole other can of worms covered in another very long thread. Hopefully that's behind me **knock on wood**

The Silvertowns where made by Coker using the old BF Goodrich molds. At least that's what we were told. Have the same tire on the '57 Fairlane 500 with no issues. Of course that doesn't really mean much, but we'll see.

[Dobie Gillis]

I've had no luck with Coker tires. I run Diamondback radials on the Merc. Unlike Coker, Diamondback does not make tires, they buy brand name tires from various manufacturers and apply their proprietary whitewall compound to them. Mine are actually Toyo.

[yblock57]

Originally Posted by Dobie Gillis

I've had no luck with Coker tires. I run Diamondback radials on the Merc. Unlike Coker, Diamondback does not make tires, they buy brand name tires from various manufacturers and apply their proprietary whitewall compound to them. Mine are actually Toyo.

I have heard good things about Diamondback. Went through 2 sets of 'Coker Classic' bias-plys and finally went with the Silvertowns as we had good luck with several sets in the past.

Call me stubborn, but I like the pie crust sidewalls on the bias-ply tires vs the more modern radials. Handling isn't a concern (obviously)! These cars only get out for weekend fair-weather cruising.

Will get the car out this weekend for some testing and get it back on stands and report back results.

[miker98038]

I currently have 2 sets of Diamond Backs, one BFG and one Nitto. Both are great, but getting old. I’ve also got a set of the Coker Bias look radials, 6.50 15 and 8.20 15’s and they balanced easily, and drive great. Way better than the previous bias ply’s. Both company’s are pretty proud of their products and your wallet feels it.

To the original topic, replacing the old A arm bushings is a pain, but it made a big difference in my 55 bird.

[KULTULZ]

Mine are actually Toyo.

The side walls on your tires are branded TOYO on a '53 MERC?

Have you no shame?

[Dobie Gillis]

Yup, they're Toyo made in White, GA. You'd only know they're Toyo if you crawled under the car and looked; the process of adding the whitewall obliterates the name.

[KULTULZ]

... well ...

I guess I can save the GIG if the name is hidden ...

[KULTULZ]

I'm having a little difficulty with this thread, so please bear with me ...

... we had a reputable driveshaft shop check it out and install Spicer universal joints.

You sent out the shaft to a driveshaft shop to replace the joints and not ask to check the balance?

[dmsfrr]

Originally Posted by yblock57

I have heard good things about Diamondback. Went through 2 sets of 'Coker Classic' bias-plys and finally went with the Silvertowns as we had good luck with several sets in the past.

Call me stubborn, but I like the pie crust sidewalls on the bias-ply tires vs the more modern radials. ...

yblock57, Diamondback sells a classic style radial with the pie crust edges.

https://dbtires.com/product/auburn-d...l-15-16-sizes/

.

[yblock57]

Originally Posted by KULTULZ

I'm having a little difficulty with this thread, so please bear with me ...

You sent out the shaft to a driveshaft shop to replace the joints and not ask to check the balance?

This is my dad's car. He handled that part. Happened several years ago. He's old. He can't remember what he told them. Can't find receipt. Going on 2nd hand info here. Sorry for the confusion.

[KULTULZ]

Originally Posted by yblock57

This is my dad's car. He handled that part. Happened several years ago. He's old. He can't remember what he told them.

Can't find receipt. Going on 2nd hand info here. Sorry for the confusion.

Not your fault and now I understand. I thought you had it in a shop going through all of this (I am an old fart too).

If switching tires does not solve it, maybe take the shaft and have the balance checked.

Funny things can happen when putting radial tires on an early steel wheel that was not designed for the increased load.

[yblock57]

I ran the car on stands up to 70 and didn’t feel what I feel on the road. Minimal vibration from the drivetrain spinning up that fast. I guess that rules out driveshaft, mounts, etc.

What I do see are very wobbly rear tires and questionable rims. Hard to determine if both are at fault. YouTube video below. FYI they’re turning at about 15 mph… can only imagine what they look like at 70!

https://youtu.be/E2q_aya7AkI

Thoughts?

[Anteek29]

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Based on the video I just don't see sufficient variation to be a concern. The rims seem fine. Must look elsewhere.

[dmsfrr]

It's easy to notice the whitewalls aren't centered too well but that shouldn't matter.
One of the wheels (LR?) has a bit more run-out than the other, not sure it's enough to be a problem.
In the video there were a few moments the tires showed a little more wobble than I was expecting to see.

Have you tried swapping those tires & wheels with the ones from the Fairlane?
That should give you something else to compare to the ones currently on the T-Bird.
.

[yblock57]

Originally Posted by dmsfrr

It's easy to notice the whitewalls aren't centered too well but that shouldn't matter.
One of the wheels (LR?) has a bit more run-out than the other, not sure it's enough to be a problem.
In the video there were a few moments the tires showed a little more wobble than I was expecting to see.

Have you tried swapping those tires & wheels with the ones from the Fairlane?
That should give you something else to compare to the ones currently on the T-Bird.
.

I haven't had the chance to swap wheels yet. Fairlane is 3 hours away at Dad's place so logistics will take a while.

In the meantime I'm going to swap fronts to back and see how they act. Also going to verify axle runout.

[yblock57]

Eye-yi-yi … so much for wheels/tires. Upon checking for axle run out, a heck of a noise/vibration started. Does not do this in park. Only in reverse/drive. Double checked U-bolts. Can feel a small amount of slack in the yoke going into tail shaft of transmission. I have just replaced the bushing inside the tail shaft. Looks like it’s already leaking after putting a couple hundred miles on it. Doesn’t make sense that it would make that much noise and vibration at approx 15 mph in the video. Sounds/feels like it’s coming from inside the trans. What the heck?!?

Thoughts?

https://youtu.be/UMRg6J2dwVo

[KULTULZ]

Exactly where is the banging coming from, the front or rear joint or both?

You have checked both trans and rear fluid level? Are the u-joints grease-able or sealed? If that drive-shaft is vibrating it will eat a rear bushing/seal in no time.

[yblock57]

Originally Posted by KULTULZ

Exactly where is the banging coming from, the front or rear joint or both?

You have checked both trans and rear fluid level? Are the u-joints grease-able or sealed? If that drive-shaft is vibrating it will eat a rear bushing/seal in no time.

Trans & rear are both full. Universal joints are the spicer sealed variety.

Sounds like it’s coming from up front. Hard to tell for sure since the shaft makes it reverberate.

When I changed that bushing, it fit nice and snug on the input yoke. I guess it’s worth having it spun and checked for balance before another bushing goes in.

Thanks

[yblock57]

Update — driveshaft balanced with new universal joints and slip-yoke. Wrong yoke had been in there for a long time. New correct yoke for the Fordomatic was over 2" longer than the one that came out. Suspect it was for a 3 speed. Anyway, with that solved a new output shaft bushing & seal got everything wrapped up. No more noise!

Did some crude measuring with a stand and caliper measuring on the outer lip just inside where wheel weights go. Runout is as follows:
LF — .026”
LR — .079”
RF — .027”
RR — .025”

Obviously that left rear is the most concerning. I made a video of the inside of the wheel showing some concerning brake drum movement. If you watch closely, the inside lip of the drum appears to be moving in & out. I checked the axle flanges with the drums removed and didn't notice any runout. Is it possible the drum is tweaked somehow and causing that excessive runout? Thoughts?

Video here

[KULTULZ]

Originally Posted by yblock57

Did some crude measuring with a stand and caliper measuring on the outer lip just inside where wheel weights go. Runout is as follows:
LF — .026”
LR — .079”
RF — .027”
RR — .025”

Obviously that left rear is the most concerning. I made a video of the inside of the wheel showing some concerning brake drum movement. If you watch closely, the inside lip of the drum appears to be moving in & out. I checked the axle flanges with the drums removed and didn't notice any runout. Is it possible the drum is tweaked somehow and causing that excessive runout? Thoughts?

Video here

A steel wheel rim is stamped then formed into a circle and welded at that joining seam. Depending on the age of the wheel, it was not an exact science. The plate will have varying thickness.

The drum may be warped. It needs to go on a brake lathe to confirm concentric/out of round.

Has this been mentioned, the tire may be out of spec.

[yblock57]

Originally Posted by KULTULZ

A steel wheel rim is stamped then formed into a circle and welded at that joining seam. Depending on the age of the wheel, it was not an exact science. The plate will have varying thickness.

The drum may be warped. It needs to go on a brake lathe to confirm concentric/out of round.

Has this been mentioned, the tire may be out of spec.

Thanks, Kultulz. I’ll be talking a close look at all the above. Brake lathe is a great idea. Appreciate it [emoji1303]

[Gene F]

I used to work for a professional drag racer. (super stock). He once found a rear brake drum that threw a weight. confirmed it when he put it on a bubble balancer. You know, like you'd balance a tire with. The thing flopped completly over....

[Pete]

This would be a long shot for you since you have checked so many things already. This is fairly easy to check.
I have had two 9 inch rear end cars in the shop in the last 20 years that had the same symptoms as you and I went through many of the checks you have already done.
In both cases here it was the flange yoke on the rear end that was hammered out and would not hold the cups tight side to side.

[yblock57]

Originally Posted by Gene F

I used to work for a professional drag racer. (super stock). He once found a rear brake drum that threw a weight. confirmed it when he put it on a bubble balancer. You know, like you'd balance a tire with. The thing flopped completly over....

Neither of the rear drums have weights on them. Don't see any evidence they ever had any attached. I need to go have them turned and give them a close look on the lathe.

Thanks for the tip.

[yblock57]

Originally Posted by Pete

This would be a long shot for you since you have checked so many things already. This is fairly easy to check.
I have had two 9 inch rear end cars in the shop in the last 20 years that had the same symptoms as you and I went through many of the checks you have already done.
In both cases here it was the flange yoke on the rear end that was hammered out and would not hold the cups tight side to side.

The cups seem to be ice and tight in the yoke. I replaced the nuts & lock washers on the u-bolts. I'll give it another close look just to be sure.

When running the car in gear on jack stands, there isn't any vibration anymore, so it's making me lean towards rims/tires.

Appreciate it!

[yblock57]

Drums were put on a lathe and checked. Both are fine. Looks more and more like rims/tires are the issue here. Can see a slight up/down on the tread when spinning. Need to see what discount tire can do for me. Hopefully can replace as these have less than 500 miles on them.

[KULTULZ]

Are the wheels original to the car or a mis-match? Are the tires quality or EL CHEAPO's? The 57 BIRD used special KH wheels ($$$).

Tire run-out can be measured.

- https://evanstire.com/understanding-tire-runout/

Also SEARCH bent wheels and tire run-out.

What shape are the shocks in? Are the springs still springy? Bushings still bushy?

Is the car a driver or a restoration?

[yblock57]

Originally Posted by KULTULZ

Are the wheels original to the car or a mis-match? Are the tires quality or EL CHEAPO's? The 57 BIRD used special KH wheels ($$$).

Tire run-out can be measured.

- https://evanstire.com/understanding-tire-runout/

Also SEARCH bent wheels and tire run-out.

What shape are the shocks in? Are the springs still springy? Bushings still bushy?

Is the car a driver or a restoration?

Hey, Kultulz.

The car is just a driver. Wheels are all ‘57 thunderbird KH steel wheels. I bought an extra set from another local club member who put the KH wires on his car. A couple of the wheels in the original set to the car had bent outer lips. Made 1 set out of 2 by spinning them on the front hub and ‘eyeballing’. Not the best system, but all I had at the time.

Tires are BF Goodrich Silver Town 7.50x14 bias ply repopped by Coker. Bought in 2017 but not run right away as the Fordomatic went out on the first trip. Didn’t notice any vibration on the highway when they were fresh. We have run several of these on other cars with no issues. I can spin the tires and see radial run out. All 4 definitely have that issue. Tires have less than 500 miles on them.

Shocks are brand new Monroe gas units.

Bushings all appear original (ish)… definitely needs upper/lower A-arms as they look very crusty. Car doesn’t wander & tracks straight. Feels as tight as the ‘57 Fairlane and ‘56 Crown Vic dad has — except those are manual steering cars and the bird is power.

Springs are also likely original. Rears sag a little. You can bounce the car, so they still seem ‘springy’

I guess what should be done before any other parts are thrown at it is to swap the 14’s off dad’s 57 fairlane onto this ‘bird and see what happens. I’m pretty confident it’s going to come down to tires. Don’t feel the vibration when the car is run up to speed on jack stands.

Car is not pleasant to drive at speeds over 50 mph.

[yblock57]

Just to update this; the tires were the issue. New ones completely solved the vibration. Got the car up to 80 mph and feels great.

Appreciate everyone's help. So glad this is fixed. Now on to the next thing!

[Patrick brophy]

Yblock57,private message sent.

[Daves55Sedan]

Oooookaaaay. That is very disappointing that we are spending $300 plus for tires that are good for nothing more than 4th of July parades (5mph).
I'm all about HIGHWAY baby !
So another pair of tires costed you what, over $600.00 ? And the barely used ones go in the trash? Totally unacceptable to me.
I'd send a letter with a receipt for the ones you got from them that their tires are garbage and that you will never being spending a dime with them again.

[yblock57]

Originally Posted by Daves55Sedan

Oooookaaaay. That is very disappointing that we are spending $300 plus for tires that are good for nothing more than 4th of July parades (5mph).
I'm all about HIGHWAY baby !
So another pair of tires costed you what, over $600.00 ? And the barely used ones go in the trash? Totally unacceptable to me.
I'd send a letter with a receipt for the ones you got from them that their tires are garbage and that you will never being spending a dime with them again.

Nope. Tires are being warranted out. They’re out of stock (like everything else), so discount tire gave us a regular set of radials to run for now. Not about to leave $700+ on the table.

[wellcraft17]

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Out of curiosity I would have checked the balance of the brake drums as they have no weights and the factory didn’t balance them. Had a similar problem on my 56 f100, balancing the drums solved the problem. Used an old school bubble balancer, worst drum was 4ozs out.

[dmsfrr]

Originally Posted by yblock57

.....
Tires are BF Goodrich Silver Town 7.50x14 bias ply repopped by Coker. Bought in 2017 but not run right away as the Fordomatic went out on the first trip. Didn’t notice any vibration on the highway when they were fresh. We have run several of these on other cars with no issues. I can spin the tires and see radial run out. All 4 definitely have that issue. ...

This is apparently a fairly common problem from that tire manufacturer. Even when they're new, poor quality control and their customer service can be lacking as well.

[yblock57]

Originally Posted by dmsfrr

This is apparently a fairly common problem from that tire manufacturer. Even when they're new, poor quality control and their customer service can be lacking as well.

You can say that again! This will be the last set we run from them.

[yblock57]

Originally Posted by wellcraft17

Out of curiosity I would have checked the balance of the brake drums as they have no weights and the factory didn’t balance them. Had a similar problem on my 56 f100, balancing the drums solved the problem. Used an old school bubble balancer, worst drum was 4ozs out.

That is a good point. Same with this 'bird. No weights. Didn't have a way to check balance on them. Did you use an old style tire/wheel balancer to check yours?

[wellcraft17]

Yup, got an old school Bada M-60 bubble balancer, circa 1960s, and balanced all four drums, all of them were out of balance. One thing about a bubble balancer is gravity don’t lie.

[yblock57]

Originally Posted by wellcraft17

Yup, got an old school Bada M-60 bubble balancer, circa 1960s, and balanced all four drums, all of them were out of balance. One thing about a bubble balancer is gravity don’t lie.

Very handy thing to have. I'd like one of those along with one of those Hunter wheel balancers where you can do them on the car.