Vibration after new Goodyear tires

Did they do a proper a spin balance, or just an old school bubble balance?

 

Sounds like the dealership is the problem. They’re either not balancing the wheels correctly, or they have failed to find a balance problem in the driveshaft/brake rotating assembly.

Try a different shop.

 

My first thought was a bad tire. It happens. Sometimes a tire requires too much weight added to "balance", sometimes its a factory defect. As far as the clicking cv concern, it should repeatable on a sharp turn to the left or right with the windows open. It sometimes helps to add your location to your profile when asking for help so local referrals can be suggested.

 

Dynamic (“spin”) balancing is mandatory for a highway use vehicle. Personally, I would only use a reputable tire and alignment shop with the proper equipment. Dealerships should have this, but may not, or may have techs who do not know how to properly use it.

Echoing rjparker, you may have a tread separation, which can happen, post-manufacturing, which would be a factory defect.

 

How big are the weights on the rims? I've heard the old-school approach is: if there's a really heavy weight spec'd by the balancing machine, the operator would dismount and rotate the tire some, to reduce the weight required?

Also, is there one particular corner the vibration seems to be coming from? Or no?

 

I had a problem with a tire balance/vibration at freeway speeds with a new set of Michelin's. They were installed on our 08 Odyssey at Costco. I returned the car to the store and they rebalanced the tires but the problem persisted.

I wondered if it might be because the tires had taken a set and needed to be driven a few miles to warm them up and round them out. I took the car for a 20 mile drive and then returned to Costco. They rebalanced them again and it fixed the problem.

This Odyssey isn't driven every day now that we have the Prius and when we do drive it, I still notice a bit of the flat spot effect for the first couple miles, especially in cold weather, until the tires round out/warm up and then they are fine for the rest of the day.

 

It’s easy to flat-spot tires, but I’ve honestly never heard of un-flat-spotting them... go figure.

 

Most medium to low quality tires will slightly flat spot after long periods of inactivity (not two days) and they will always recover when run. I doubt the OPs problem is flat spotting when they are Goodyears and the problem occurs over 70 mph. He does mention a cv joint type noise. After three trips to the dealer I would find a Goodyear store. One could take another known good car and find a few miles of smooth highway where that car rides fine at 75 mph. Check the Prius tires for overinflation, somewhat common at some dealers. And then test the Prius on that stretch. Sometimes people expect a car with $800 worth of new tires to ride like a $100k Audi A8L when its just an eco box. However it will ride smooth on a really smooth road.

 

It'd still be interesting to hear from OP, regarding:

1. Is there any particular corner the vibration seems to be coming from?
2. Do any have of the wheels have unusually heavy weight correction?

Just speculating, regarding #2: maybe wheels with heavy weight correction are more prone to vibration at certain speeds? Also, if the operator notes the need the for heavy weights, dismounts and rotates the tire (180 deg?), I believe that should reduce the weight correction needed??

 

If the mounted tires were only bubble balanced and outside clip-weighted, they can still be significantly unbalanced at speed, when rotating. Are there any inside weights? Any evidence of the right rear having thrown a weight? (Witness marks on the rim where there was a clip mounted.)

 

A few thoughts:

1. There should be at least a few inside weights. Maybe there are, just hard to spot?
2. Isn't it traditional with Prius rims, to use hidden weights for the outside? Do the covers ride up at the weights?
3. Not sure what the 30 signifies, but that seems like a long weight. Would rotating the tire on the rim improve things?

 

No weights on the inside means they most likely are not balanced. On the Prius rims, I have had new tires installed and they have always put the weights on the inside. Balancing tires, beleive or not, is an art. Some people just look at the digital read out and as soon as it is within "specs" range, they are done. To really do this, the tech should spin it and take it down to the smallest variation. This almost guarantees a good balance. Most shops assume the driver will not be going over 65mph and set the spin for that. A good shop goes for 95mph with minimal variation. Just my two cents.

 

Most likely it is a "tech" issue. In otherwords, the person who is doing the work. I'm sure the equipment is good. Suggest they check the balance all the way to 95mph.

 

The need for dynamic balancing and the use of inside weights increases with larger backspace, positive offset rims, such as are used on many FWD vehicles. (Or on 'deep dish', small backspacing, large negative negative offset rims as were once popular on RWD vehicles.)