Highway speed vibration ('57 Thunderbird)

[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.