Bad Vibration - Help needed

This is kind of long, but I'm hoping a few of you will go through the whole thing and help me figure out what to do/look at next. In summary, this car has been on the road 15 years - I swapped out the front disks for drums and changed the wheels and now have a vibration problem.

What I had:
- 1940 Ford, CE dropped axle, Ford spindles up front with Volare disk brakes, Currie 9” out back with 11” drums, radial tires all around, IH steel centers in modern rims built by Stockton 6 or 7 years ago. No vibration issues until now.
- The tires are 10+ years old and visually in good shape – no funny wear, etc… The new F100 wheels would be the 3<SUP>rd</SUP> set these tires have been on.
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What changed:
- Removed Volare disk brakes, installed 56 F-100 drums and hubs
- Hubs came from a pretty good cast-off front end – not a driver but a roller anyway
- Drums came from a friend’s ’39 Ford – running driving car for many years
- Had the rear axles redrilled by a toolmaker friend and installed new studs
- Built new wheels – F100 centers in 15x5 and 15x7 rims from Rally <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-comffice:smarttags" /><st1:country-region w:st="on"><st1lace w:st="on">America</st1lace></st1:country-region>
- Bought new rears from Rally <st1lace w:st="on"><st1:country-region w:st="on">America</st1:country-region></st1lace>
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What stayed the same:
- Spindles, both axles, all 4 tires, rear brakes, springs, shocks, etc…
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History:
- Had 4 tires mounted and balanced on 4 new wheels at Tire Shop A
- They put 12oz on one of my homebuilt rear wheels and said the other needed more that 16oz to balance so they didn’t do anything with it. Rear end vibration showed up at around 50mph and I never pushed it much farther than that.
- I knew the one rear wasn’t that good to start with and the lugs holes in both were useable, but a little big so I ordered replacements from Jimmy (2 weeks to get centers, weld and ship J)
- Didn’t feel great about Tire Shop A, so I took the new rears to Tire Shop B for mount and balance. Rear vibration gone.
- At this point I was getting a front end vibration at closer to 60mph in the left front corner. I don’t feel the vibration in the steering wheel or brake pedal – the whole car shakes. The vibration is dependent on road speed – not engine speed.
- I looked at static balance using a spindle/hub setup I used to build the wheels.
- Seemed OK but not great so I took the fronts and spare to Tire Shop B for a rebalance (not a remount).
- Things changed a little – one had .25oz from TSA and no weight from TSB. The other had the same weight but they moved them over ½” or so. Same story with the spare.
- Tire Shop B showed me one wheel on the balancer and said it balanced but looked bent.
- Mounted the wheels on the car – vibration on LF corner same as before, wheels in same location as before.
- Swapped front wheels side-for-side and vibration seemed to move to the RF corner.
- Tried the same thing with the spare with the same results.
- Put all 3 wheels on the bench mounted spindle/hub to measure both lateral and radial runout. My wheels are at least as good as the old ones from <st1:City w:st="on">Stockton</st1:City> (and the rears from Rally <st1:country-region w:st="on"><st1lace w:st="on">America</st1lace></st1:country-region>).
- Checked lateral runout on the hubs (<.010”).
- The drums were pretty clean but I had them turned anyway – radial runout better than .010” on both
- Looked at static balance on the drums. Didn’t look that great but neither did my spare drums. Don’t know what’s normal.
- I’ve never been real conscious about which tire goes on which side of the car. I ***ume they’ve all been run on both sides before.
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Questions:
- Do the drums need to be balanced?
- Could Tire Shop A have somehow screwed up when they mounted the tires?
- Could I have messed up the tires somehow when I took them off the Stockton wheels? I did all of them manually with an HF tire changer and did one on the floor with various implements of destruction.
- Is there some catastrophic limit to the number of times you can mount a tire?
- What next?

Thanks for reading this far. I really don't know what to do next and am hoping for some good suggestions.

Chris

 

put the disk back on.....my a did the same thing...about 60 to 65...and it was all over.....6 pairs of tires and wheels...drums , hubs , i couldn't get the shake out....steering dampners, i tried a lot of stuff...shocks, added a leaf , took out 2 leaves...finally gave up and put the disk back on and the car was good past 95 mph....brandon

 

I'd find a tire shop that can spin balance the Tires on the car. It used to be a common thing but not so much any more. I've seen drums with weights welded on them. It sounds like a balance issue and this would eliminate that question.
The Wizzard

 

This right here sounds like your problem is in one definite tire/wheel ***embly. Have the wheels balanced without the tires mounted to determine the "goodness" of each. Mount a different tire on the suspect wheel and see if it changes, if it does, then the original suspect tire is most likely the culprit.

 

Thanks for the comments so far.

I should mention that all 5 wheel/tire ***emblies are now considered to be balanced by the tire shop - even the one they thought looked wobbly (it isn't actually any more wobbly than the others per my dial indicator measurements).

I checked the rear drums on the hub/spindle and they seem to be balanced pretty well. They are the newer style with weights on them.

Time** - where about in the middle of MN are you?

 

At our shop we have a raod force wheel balancer from Hunter, it will actually put a load on the wheel and tire ***embly as if it were really on the road. It will let you match mount the wheel and tire so you put a minimal amount of weight on it, theoretically minimalizing vibration. Also will tell you if you have excessive wheel run-out or exvessive road force variation, etc. What I'm getting at is that I think if you go to the Hunter Engineering?/ wheel alignment web page and enter you ZIP code it will tell you the shop closest to your location with this machine. Ok www.hunter.com ,click on wheel balancing, then click on locate a GSP9700 give it a shot.

 

Huh - the napa replacement drum for the '56 F100 appears to have a weight on it.

 

Litterally in the middle, town of Isanti. About 60 miles N of the cities.
I work in Bloomington, a few blocks from the MOA.

 

you could have just your hubs/drums balanced...i had that done on some ford hubs/buick drums and they were off quite a bit. if i recall correctly cost me about $25

are you sure your redrill of the bolt patterns was done right? could be they are off center and they are going around in a ellipse

 

The new bolt pattern is rear only and yes I'm confident that it's accurate. The drums would never fit (and certainly not in more than one orientation) if it was off much. The fronts are a Ford factory 5.5" pattern.

What type of shop does drum/hub balancing? I was wondering if that was possible. The replacement drums are not especially cheap.

 

it was a place that balanced stuff for industries . found them in the yellow pages and they were local to me. they claimed they could balance anything..the guy kinda showed off a bit , got the balance within 1/100 of a gram .i needed to do it because the factory weights on the drums were gone

midwest balancing 507-455-9036....i'm sure if you check the yellow pages you could find someone close to you


the idea of balancing it on the car may be good advice too

 

Up once for day shift. Any other suggestions? Comments on what's been said so far?

I hope to get on a Hunter road force machine today or tomorrow and I'll keep you posted on my progress.

Chris

 

i have found some old drums that were really really bad before..
i still have one on my 53 that if i spin it and let it settle..it will always stop in the same place. out of balance.
i would also start to look at your spinning ***emblies to see what could be out of balance.

 

Got a lathe?

I'd put the drum only on a chuck, spin it up and see if you can feel the lathe vibrate.
If it does, take the drum to a shop that balances engines and see if they can balance the drums for you.

Seems too, a static balancer could indicate a drum out of balance.

I'd try a different pair of wheels & tires if you could.
Borrow a pair from a friend?
A pair of junkyard specials that still have balance weights and a reasonably good tire doesn't cost too much at Pic a Part here.

 

You can balance the hub /drum your self,here's how;
When regreasing wheel bearings is a good time to do this,and replace seals after[one time deal.
First is check that the drum fits hub same spot[center and lug]every time[mark if needed],that all lug nuts are same. With axle jacked up and tire/rim off,take hub/drum off,remove seal ,clean grease out,clean bearings very good,[be sure there good],back adjustment of brakes,to free spin.Now to balance;
Temp,Put a lite oil[WD40 works]on bearings and replace hub/drum on axle with out seal,spin to be sure it is turning very free,let it come to a stop,put a mark at bottom outer edge,then spin again,to check if you really found heavy spot,make sure it retuns to same spot each time after spin.
OK, now just move marked spot up to, like from 6:00 at bottom to 3:00 or 9:00 if a clock] and let it go,see and note how fast it moves back to 6:00= tells you how bad off it is, now you can drill off steel at that mark or add some to 12:00 spot,tell you can move your heavy mark up to the 3:00 or 9:00 and it stays there.
After thats done,replace the tire/rim and you can then do the same thing to tire/rim to balance them also,but with tire lead WT. or sticky lead by adding it across from heavy spot.

 

I took the two front wheels and spare in for road force balancing today. The one with no weights on it came in at 13 lb and still has no weights. The other two were at 26lb and 31lb respectively. I didn't get to talk to the tech but will stop in tomorrow for his evaluation. Is there some practical limit to the number of times you can mount/demount a tire?

I haven't tried the spare yet, but put the two fronts on and still have some vibration, although it's better (less amplitude, narrower range of speeds and didn't seem to move when I swapped wheels side-to-side). Next step is to balance the drums, I suppose.

Dana - that's pretty much the setup I used to build the wheels - just mounted on a workbench. Do you have any feel for acceptable size/depth of hole that might be safe? I wonder weather stick-on wheel weights might be better.

C9 - No luck yet on borrowing wheels - I'll keep asking around. All this time at work is really chewing into my hot rod time.

 

on mountig/removing tires...Yes, there is a limit.

problem is, it's gonna be different on every tire. The belts around the bead are the tightest ones, and the ones that take the abuse. removing and installing the tire is really the only thing that beats them up real bad, sooo, while the tire will balance out fine, and look right, the end result is a tire that behaves weird under a load- much like a seperated tire.

easy way to check it out.

with the tires on the front, at very low speed, (less than 20) take both hands off the wheel and see what it does. a pull or slight movement in the spinnaker means bad tire.

I wouldn't reccomend this test during rush hour or on a busy street.

 

Bias ply tires go out of round sitting for a long time.
give your wheels a spin holdig a pointer close to the tread
and see if the gap stays the same.

 

Whoops radial tires

 

Update - according to tire shop dude (who seems pretty good by the way) the wheels are good and if there's a problem its the tires. He says anything over 20lb RF is no good.

I did a static balance on the drums (3oz on one and 2oz on the other). This improved things drastically. Vibration is much better and back to moving with the wheels. Looks like some tires might be in order.

 

Take all the weights off, and go drive it. See if it gets better
Jimmy

 

2 questions
1. Was anything wrong with the disc brakes?
and
2. Are you running fenders?

cause if you have fenders and the discs worked well, the problem is solved.

 

53s - the front track was too wide with the disks. It's a 40 Ford - of course it has fenders ;-)

New tires and balanced drums seems to have solved to problem. Balancing the drums made a huge difference. Tires got me the rest of the way there.

Thanks for all the help and suggestions!