tire balance issues?

[rh71]

After getting new tires/rims, I had a problem when accelerating on a highway between 60-65mph where the front seats vibrate. Since it's not in the steering wheel I'm guessing it's the rear wheels not properly balanced. Had them do it again and this time it happens at 70-75mph. One thing I noticed is that the longer I drive that session, the more likely it goes away at the problem-speed, but of course it's no guarantee. Next time on the highway it acts up again.

Shouldn't a balancing issue be constantly problematic instead of intermittent? When they do a balance, do they ever remove the rubber from the rims and re-do it or do they just mess with the counterweights? Would an out-of-round rim pose only intermittent issues like this?

 

[Vette73]

Might be a bad tire. Could be a belt is shifting/broken in the belt. It is not that common but I have seen it.
Does any tire have high/low spots on the sidewall?

 

[ayabe]

I'm facing the same issue strangely enough.

Got 4 new tires 3 weeks ago, get vibration when accelerating from 70mph.

I lost a tire on Monday due to some road debris, had to order a new tire, went to have it put on and asked to have them check the balancing on the other 3 tires. They checked and didn't find anything abnormal.

This morning driving to work....the vibration is a little less noticeable but still there. Do these people just not know how to balance tires properly or should I be looking elsewhere for the answer?

 

[AMCRambler]

Marlin makes a good point. Although the shop should notice that when they balance the tire as it will take them a couple tries and still won't be exactly right.

I'm thinking maybe a bad wheel bearing in the back? Is there any audible noise associated with it? It may be difficult to hear at that speed though. You could try riding in the back seat with someone else driving and listen to both sides at that speed.

 

[rh71]

Would road-force balancing rule out the tires/rims completely or would there still be a chance they are the culprits?

The sidewalls look fine.

A wheel bearing would be associated with the vehicle warranty and not possible damage done by a tire installer, correct?

 

[ayabe]

I found a local shop that has one of the gsp9700 road force machines. I think I'll take it to them after work today and see what they can do.

 

[Zenmervolt]

Wheel bearings will make noise, so you should notice that in addition to a vibration.

Brand-new tires have a tendency to cause vibrations, etc for the first 500 miles or so as they wear in. It may be as simple as that.

ZV

 

[slag]

I've been having the same problem. Got 4 new tires installed and vibrations from 60-75 mph. Called the shop and they said they balanced them already and want to charge me again to rebalance. At this point, i'm not feeling too positive about their methods so I might take them somewhere else to rebalance. I generally have to have shops balance my tires a couple times before they get it right without vibration issues, but this is ridiculous

 

[overst33r]

Find yourself a 9700GSP, if that can't balance it, the tires are out of round.

 

[ayabe]

Just wanted to give an update.

I ended up paying for another balance at another shop using a gsp9700 machine and the Subie is smooth as silk on the highway now.

Ended up costing me $15 per tire, so $60 in total.

Anyways if all else fails give this a try.