Hello, Gents. I purchased a car that was tubbed and features 375/60/15 Pro-Trac bias-ply tires. I've tried different air pressures. At around 55-60 MPH, the rear end wobbles and shakes the car. Any ideas of how I can solve the issue? The front has skinnies -- 165/85/15 radials. What is the proper tire combination? All radials? It's a street car set up like a drag car. 406 tunnel ram with heads. Thanks!
Not sure how it works bias/radial combo, ive only driven with one type at a time. But wobble and shake, to me its a balancing problem, check the rims, and how old are the tires, are they egg shaped after sitting too long? the questions are many
have you watched the tires as they rotate, to see if the treads are concentric? or if they move in and out as the tires turn? I thought Pro Tracs were from Coker? who has a bad reputation lately for making out of round tires. I had a pair of Coker brand bias ply tires a few years ago that did that, I wound up taking them to California to get shaved, they were better after.
I have driven lots of cars with radial skinnies and bias rear tires although not quite that wide with good luck other than some walking in the rear on roads with ruts worn in them. As mentioned, sounds like your tires are either not round or not in balance.
This is the last version of my old T bucket, big and littles, bias and radials. After correcting the ackerman, this thing rode pretty nicely. On the interstate at speed, around town, it didn't matter. Find a old school tire shop, maybe a truck shop, they may be able to help if they are out of round. Don't over inflate, had N50's (several sets) on my GTO, probably 20psi max. If all else fails a couple smoky burn outs might help! Oh, pics..,,,,show us what ya got!!
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