Wheel balancing: word to the wise

[Ciaopec]

When purchasing tires at COSTCO or having your wheels balanced, remind the technicians to use gram weights as opposed to ounce weights. The gram weights are thinner. I heard a knocking noise when making turns so I took the car to Tesla thinking I had a bearing going bad. After investigating Tesla replace the ounce weights with gram weights and the problem was solved. I just replaced my tires today (after 57000 miles; they had just reached the wear bar) and as I drove away the knocking sound happened again. I immediately took the car back and the guys rebalanced the wheels with gram weights; problem solved!

Edit: As I think about it, I suppose it is good advice wherever you have your work done. The thick weights will scrape on one of the suspension nuts in front.

 

[alehbaba]

which tires did you go with?

 

[JHWJR]

That's pretty good mileage for 1 set of tires on these cars!

 

[Ciaopec]

which tires did you go with?

Michelin Pilot Sport A/S 3+. I have always had good luck with Michelins; not so much with other brands. Everyone will have a different opinion. These had the highest speed rating (y) for what it is worth and they were the least expensive and they were on sale. Fortunately, I am lucky enough not to worry about the price (but maybe only because I have always paid attention to the price).

That's pretty good mileage for 1 set of tires on these cars!

Yes. I can no longer find the document that showed I was supposed to get Michelin MXV or something delivered with the car. It actually came with Goodyear tires and I was so giddy to receive the car after what seemed an interminable wait that I never protested. On my first road trip I hit a broke wooden pallet in the middle of the road. There were others alongside the road who had done the same and were checking their tires. I should have but instead only looked to see that mine were holding pressure. It wasn't until the next day and some 450 miles later that I realized I now had large blisters in the sidewalls. Replaced those with 2 Michelin tires. But two of the original Goodyear's stayed on through 57000+ miles. They were almost at the tread wear bars. That and I broke the rear end away on a wet road for the first time ever made me think it was time to replace. I think AWD helps and proper pressure and rotations. Surprisingly, I don't think I baby the car and am pretty aggressive in curves.

 

[scottm]

So this thread isn't really about costco.. or costco tires.

It's about balancing weights and rims... I get it.

This can happen at any tire shop balancing your new rubber.

Tesla front lower suspension arms are bolted to the knuckle with the bolts pointing downward and two of them just come short of hitting the rims. Less than about 1/4 inch clearance there. So when balancing and putting a chunk of lead there ... if it's too thick of whatever style they use ... WHACK those bolts will knock the too-tall weights off in one wheel revolution, if they were unlucky enough to be in-line with those bolts. Which mine were.


A quick shop might take the car off the lift and drive it away without checking their work, and the car will be out of balance before it gets out of the garage.

A good tire shop (who is also mounting the wheels on the car) will give a wheel a spin while still in the air and check for clearance between the weights and suspension bolts. I watched as they did this for me.

The rear suspension is not a concern. Tons of clearance. BUT when you rotate wheels (like I do at home) you'll want to know the rears will be able to move forward with not hits.

I didn't want a bunch more thinner weights and have to do a re-balance... so I opted to grind the suspension bolt down by about 1/8" ... done. Why? Because I change over wheels between seasons at home and I will typically get new rubber mounted on rims without car present from now on... and making more clearance improves my odds in future on new sets of rubber.

BOTTOM LINE: check every new wheel when it has been freshly balanced, that it rotates and weights clears suspension bolts on the FRONT of the car... even if the wheel belongs to the rear. Because one day you will rotate it.