marlinspike

So I got new tires today. I watched the guy balance them on the Hunter machine, apply the weights, and then double check them. I saw him do this for every wheel. He put the ones that needed the least correction on the front. Somehow, I now have a steering wheel shimmy at 55-65mph and imbalance on the rear wheels is perceptible in the 80-85mph range. How can they be imbalanced when I watched him balance them?

bumada

its possible that the weights didnt stick to the wheels and they just fell off. it happened to my dad 3 times with the same set of wheels. the guys werent cleaning the wheel properly so the weights werent sticking.

marlinspike

No, I checked that, weights are all on there (they're the Wurth 2 piece weights anyways, don't really come off unintentionally.

ShawnD

Their calibration is fucked?

marlinspike

Is that a thing that happens? What a royal pain. Won't be able to go back at any time this upcoming week, will have to wait until the week after. Son of a...

ShawnD

I dont know, but its always a possibility, Fabrik8/anyone else in enginerring or car shops would know more than I. Or maybe the work is showing weaknesses in the rest of the car?

Spindrift

depending on the machine, its possible the incorrect wheel measurements were put in. I know ive seen tires get balanced on the previous wheels size, like they forget to put in the new measurements.

Also yes, a balancing machines calibration can be off and isnt very common but not out of the norm either.

edit: what kind of vehicle/tire size?

marlinspike

That's another thing I'm thinking about - I did go from a 50 series profile to a 45 series profile, so maybe it's exacerbating some other issue, but then it was done at an MB shop and the tech didn't find anything out of the ordinary. Plus, it was perfectly smooth before.

marlinspike

Vehicle is a 1985 MB 380SE (well, that's what the suspension and chassis are from anyways, most things related to making the car move are something else). Wheels are 16x8 ET 11 wearing 245/45-16. I did notice for some reason the size the machine showed was 16" diameter and 8.2" width, not sure why the 0.2" extra.

You have a shop in Norfolk? I work downtown, but the shop I used was in Yorktown (live in Williamsburg) which is why I can't get to it during the week. Would you charge me to put one of the wheels on your balancer (I figure that would reveal a calibration issue) if I jack up the car and take the wheel off myself (or just bring a wheel in loose)?

Spindrift

Id have them double check the balance, and verify yourself the measurements are correct. If it was perfectly smooth before, going down in tire size wont make that dramatic of a difference.