littlebob said:
It pulled with a lot of vibration till I got the tires warmed up, about a hundred miles.If the tires were mounted and sat underinflated they may have developed the same type of flat spot. littlebob
Flat spotting was a common problem with nylon corded bias ply tires, but I've never heard of it on polyester or steel corded radial tires. I doubt the missing outer front rear duals would create the problem either, but I've been wrong at least once.
My guesses as to the problem you describe would be (in order of likelihood) flat spots on the tires if they are surplus tires; improper tire pressure (may be either too high or too low depending on the dynamics of your particular vehicle); or tires out of balance.
Ain't much you can do about flat spots unless you can identify the flat spots and mount your flat spotted tires on the same hub with the flat spots 180 degrees from each other to cancel out the condition. Tire pressures you can play with until all the air on Planet Earth is gone.
Out of balance tires is not a real common problem with bias ply tires and even less of a problem with radials, but it does happen. My Deuce's rear axles hopped around like a green bareback bronco at the Rodeo. Unfortunately, the fix is not easy unless you live in a metro area with lots of HD truck tire centers. There are a few places which spin balance the front tires while mounted on the vehicle, which works very well. There are far fewer places which will balance HD truck tires OFF the vehicle, i.e.your rear tires. After several days of searching I did find a place quite a distance from me which could balance Deuce sized tires off the vehicle, at $25 per tire, $250 for the entire vehicle set.
If you have more time than money, you could check your tires by yourself and then mount on the vehicle them so the out of balance condition is offset for each dual pair. Try this, it is a lot of work though! Take all 10 (or 11) tires off the vehicle. Mount them one at a time on the same front hub, the one which spins most easily. Spin them by hand. They will rotate for a time and then come to a stop, generally with the heaviest part of the tire on the bottom. Mark the heavy spot on each tire. Do this a couple times for each tire to make sure you have the true heavy spot. Try to approximate the relative amount of out of balance by rotating the heavy spot of each tire to the 12 o'clock position and timing how long it take for the heavy spot to rotate on its own to 6 o'clock.
Take the two least out of balance tires (least time for the heavy spot to rotate to 6 o'clock) and mount them on the front. Then match up 8 tires in pairs by the amount of out of balance - the two tires which were the quickest to rotate from 12 o'clock to 6 o'clock as one pair, then the next two quickest, etc. Mount each pair on the same hub with the heavy spots 180 degrees apart. This will allow each tire on a hub to counter balance the other tire on the same hub, effectively balancing each pair of tires on the same hub.
Not perfect, but a way to achieve a reasonable tire balance at no/low cost, albeit at a lot of operator effort!