My 71 F-100 4x4 has always had a problem on the left front tire, it seems that I can never get it to balance. I have had the tire shop rebalance and rotate the tires to try and get it to stop bouncing on the freeway but nothing I have done will stop it.The last time I had the hub off the front I checked it for roundness, it has a slight out of round situation in the casting but the wheel studs are all perfectly centered in the hub.I recently put new brake drums on but the problem was there before that. All the bushings,bearings and suspension parts are all new and tight.I asked the tire shop if the out of center casting could be causing the bounce and he said the hub is too close to the center of the wheel to cause it to shake.Anybody ever have this problem or any ideas? Thanks.
"bowties in the rearview mirror"

 

Check the tire for warpage or a broken bead of types. Our 88' Taurus had a similar problem with the back left tire. the tire had the metal bead that runs around the outer center of the tire break, and you could feel it hop. Look on the part of the tire that meets the pavement and look for any bulges or out of alignment treads. that might be your problem.

 

I have a similar problem with my 79 f150. I think my hub is out of round. At slow speed (5 mph or less) I can see the front of my truck move up and down. I think if you have a slight out of round at the hub, by the time you get to the edge of the tire it gets bigger. And the bigger the tire the more noticable it will be. Something to think about.

Chad

 

[updated:LAST EDITED ON 21-Mar-02 AT 09:40 PM (EST)]After 20+ years, the balancing weights rusted off of the front brake drums of my '69 F100 2WD. I never thought anything about them until I noticed the front tires' life was short - they would develop "tumors" and bulges where the tread would come apart. After checking many places (both industrial and automotive) that did balancing, nobody wanted to touch them. Several people even said that brake drums are too small of a diameter to worry about vibration... So I cleaned all of the grease from the wheel bearings and set them loose with only thin oil. The out-of-balance condition would cause the tires to rotate (front end jacked up) until the heavy spot was at the bottom. I removed the front tires (that I balanced several times) and the brake drums alone would do the same thing as before. I used a magnet and some scrap metal to determine the weight needed to regain balance, and then made and arc-welded steel weights to the brake drums. Make sure you repack the wheel bearings with grease. No more vibrations, and no more front tire problems.

A dial indicator is the best tool for checking the hubs' diameters and flat surfaces for runout.

Raise the front wheels and use a big wooden or cement block near the tread to check for bent rims/tire runout.

Art
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