Vibration when driving

[loubob]

Over this past Winter I:

1--installed a new 5.5 head, gasket, and plugs
2--installed a Mitchell o.d. unit
3--did a complete brake job: linings,cast iron drums, wheel bearings,Flathead Ted kit(fronts), rebuilt rear backing plates

Took car for test drive.
I now get a thumping-type noise with every complete rotation of the tires and I feel it thru the steering wheel.

A friend said it could be a bad tire(s) but have not checked that out yet.

ANY thoughts, ideas, suggestions would be greatly appreciated.

Car is a '30 standard coupe w/rs.

Thanks.....loubob

[SeaSlugs]

has it been setting on the tires all winter? If so can be normal.

does it pull or does it just thump?

Does it do it with the front axle in midair and you spin the wheels?

Does it change in loudness/force as you speed up or does it stay with RPM of the engine?

Does it get better/worse/no change when your cruising and let off the throttle?

Punch the throttle?

While semi hard braking is it better/worse/no change?

[Marshall V. Daut]

To test, move the front wheels and tires to the rear, and the rear tires to the front. See if that makes any difference. If so, one or both of the previous front tires is bad. Be sure to check the tire pressure, too.
Marshall

[BILL WILLIAMSON]

IF they're NYLON tires, they get HORRIBLE flat spots from sitting a long time. If you drive it until the tires get quite hot, it may improve. Spin each wheel & look for flat spots. When I drove D. J.'s Mom's '26 Studebaker, it felt like a clown car, with SQUARE wheels!!!!!
Bill W.

[loubob]

I did rotate tires f>r/r>f---no difference
Car on jacks all Winter
I keep tire pressure @ 35psi
Will test SeaSlugs questions on Sat. and advise
Thanks

[Tom Wesenberg]

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If any spray paint got inside the drum on the braking surface, that can give a pulsing feel to the brakes.

[Marshall V. Daut]

'Sorry for the extra work rotating tires on my recommendation, loubob. But doing that solved my vibrating and front wheel shaking problem on Tuesday, even after replacing the king pins & bushings and checking all the usual suspects. The wheels were balanced with no improvement. Out of frustration and desperation, I moved the wheels and tires front to rear and the problem went away. Apparently one or both of the former front tires has a problem and was causing the front end to shake and vibrate. It's probably still there in the rear, but not as noticeable. I'll have to next find which tire is bad. When I saw your posting, I was sure you were experiencing the same thing.
Well, keep looking. There IS a definite cause. These cars didn't come from the factory vibrating and shaking. Something is loose or needs replacing. Follow the excellent suggestions posted so far, plus future advice, and you'll find the cause.
Marshall

[Brentwood Bob]

I am thinking the spinning of each front tire might indicate a problem.
Did you replace the front grease seals with the new bearings and races?
Bob

[FL&WVMIKE]

Do you know if the wheels and tires are balanced ?
MIKE (mikeburch)

[Larry Jenkins]

Are the rims straight?

Larry Jenkins

[loubob]

No on the front dust seals. Are the grease seals different???
Tires/wheels never balanced by me and probably not by previous owner.
Unknown if rims are straight.
Will have to ask around to find someone to check them out.
Have the engine running great and now this.
You have no idea how "bummed out" I am over this.

Bob

[Brentwood Bob]

When you go back to the fix it mode spin each tire and let us know if that turns up anything.
Bob

[loubob]

Spun each tire-nothing
Tried spare on lf-no difference. Now on rf and will test it tomorrow
Vibration in steering wheel is very noticeable when I put car in o.d.
Also seems to 'come on' when I hit 40, & above
No change when cruising/letting off throttle
The car is running great. I plan to continue to drive it with/w.o. the vibration
I placed jack stands on rear axle and took car up to 40mph. Did not feel any vibration.
Heard nothing unusual either.
Thanks

[Dick So. Cal.]

Out of balance is one thing, but out of round is another.

Even a square wheel can be balanced. Just a thought.

Dick

[RandyinUtah]

I don't have any experience with Flathead Teds brake floaters but I would try backing off the brake adjusters on the front drums and just use the rear brakes during a test drive and see if the thumping noise changes. Then do the same on the rear.

[Brentwood Bob]

since you replaced the steel drums with cast iron drums I wonder if the hubs were trued up before the new drums were swedged on.
I would take off each front drum and look for unusual wear. something hitting a high point. Are the grease seals the correct size to get the inner bearing to ride correctly.
I also remember that the early rear drums did not acceept new emergency brake linings.

[P.S.]

Based on the latest info (running it while up on jack stands, etc.), and not having the vibration in the drivetrain... I wonder if it's the lug nut holes on one or both of the rims being wallered out and maybe the front wheel(s) are wobbling under certain conditions.

If that is the case, some of those cupped washers might solve it. If not, let's keep trying.

[loubob]

I'll call the place that installed the c.i. drums to ask if they trued the hubs.
I will try the brake adjuster suggestion.
I will check around to see if anyone close by can check out my wheels.
I thought about the cupped washers and will get them this week.
I thank everyone for their suggestions and will keep trying to get to the problem and advise.

[Brentwood Bob]

I would take off each front drum and look for unusual wear. something hitting a high point. Are the grease seals the correct size to get the inner bearing to ride correctly.

[loubob]

I backed off the front brake adjusters.
Weather permitting will test it tomorrow

[heneste]

If you're noticing it more when the overdrive is engaged, would it be a driveshaft balance issue or some other obstruction with the gearing in the overdrive unit itself? Is the fluid level up in the overdrive unit?

[loubob]

I filled it to the amount stated in the instruction sheet.
Bob