New Member...and A Question

Info is spread around the web - but I haven't run across a comprehensive list - at least one that is regularly maintained. Best places to grab that information is directly from their forums - corolla9.com for the 9th gen Corollas and newcelica.org for the 7th gen Celicas.

That said - the Corolla XRS/Matrix XRS 16" "dimpled" 5-spoke and the Celica GT-S both are 16" x 6.5" wheels with a 39mm offset, 5x100 bolt circle, 54.1mm center bore. The OEM Corolla/Matrix one weighs about 21lbs. The Celica one is about 15lbs.

The 9th gen Corolla can have a wheel as wide as 7" and offsets in the range running 35mm-45mm without clearance issues on stock suspension/alignment settings.

Shouldn't be the wheels - assuming they run straight and don't have an physical damage. Installing 7th gen Celica and/or Scion tC wheels are a popular upgrade to the 9th gen Corolla. The car itself is pretty for giving on wheel offsets, unless you purposely are running too wide or running excessively thick spacers (ie, stanced or hellaflush look).

You can try swapping the front and rear wheels and see if the shimmy is still there or if it follows the wheels. That will let you know if it is a steering/suspension related issue or a bent/damaged wheel.

Some 9th gens also ate through wheel bearings for some reason - many with bearing failing in the rear axle. This is thought to be do to the beam-style rear suspension setup and shims/crash bolts required to move it to a reasonable alignment and/or bent wheel hubs from the factory.

Could be how they balanced the wheel. Most of the spin balancing machines only get the tire up between 35-55 MPH - so call "high speed" balancers. The problem is, a tire that might dynamically balance out at one speed may not be balanced at another. Since you noticed the shimmy temporarily and I'm assuming it was fine when you slowed down - my money is on the balance.

See if the shop has a Hunter Road Force Touch GSP9700 tire balancer. The machine basically runs itself, so almost goof-proof. Plus it does a road force variation test to see how the tire reacts under a load. Only one of the few tire balance machines that can do this. Also checks for tire runout (bent wheels, tire pull issues), damaged tires (changes in density, high or low spots), and tire conicity (some tires can wear down into a cone instead of evenly as a cylinder)

This will eliminate a lot of the vibrations that people have seen. Sometimes, it is the technician skill that is paramount. I've seen tires that cannot be balanced, unless you spin then 180degrees. Generally not preferred, as the tire is marked where it is heaviest and lightest - but sometimes it helps with vibration/uneven tire wear.

Playing around with tire pressures can also help - some tires do between to more or less tire pressure. General rule of thumb - use the placard PSI (inside glovebox, on driver's door jam) to find out the OEM tire pressures, usually it is 30-32PSI. Look at the tires and note their max cold inflation - that usually runs from 44-51PSI. Those will give you the range of acceptable tire pressures. Personally - I start out within a couple PSI of max cold inflation and bleed the tires down until I find a speed spot. Don't worry - the tire won't "blow up" at the max cold inflation. In fact - some people run some incredibly high tire pressures as part of hypermiling. Just note that not all tires can run overpressure - as long as you stay at or under the cold tire inflation (tire manufacturers have already factored in a safety margin and temperature variations - ie, they know that pressures will be higher with a hot tire.

Ideally, you want to run a tire contact pyrometer and measure temperatures across the face of the tread after drive the car hard (high speed, hard corning, braking ,accelerating, etc). If the pressure is right, the temperature would be even across the face. Problem with that - hard to take accurate measurements of temperatures and the ideal pressure may not be the right pressure for your driving situations.

Correct, the closer you get it to actual driving conditions, the better the balance will be. Hence the Hunter Road-Force variants - they have a "roller" that actually presses down on the tire to load it with some weight.

A shop is supposed to road test it after a balance job, but there generally not a highway close by + owners get pissed off if a shop adds too many miles on the car. Another thing to ask, is when was the last time they calibrated the machine. There is a start-up self calibration, but some go out and get a balancing standard (basically a perfectly balance metal disc) - and run with that to verify balance. I'd be willing to bet that the shop only does the power on self test.

Might try a different shop or see if there is an older tech working. There are some neat tricks you can do to get a perfect balance, but usually it is the old school technicians that know this. The newer technicians never had to deal with those issues, so they won't be looking for it. Ex. tire and wheel has to be perfectly centered on the spindle for proper testing - the new machines used a laser sighter and smooth conical tapered mounting hub. Old machines were centered by "feel", as tolerances were pretty low, lots of slop in the system. You spin the tire as you tighten up the mount hub, by shifting the moment of inertia, you can center the tire dynamically. Sure laser sighting, touch screen computing, automated weight application makes it goof-proof, but doesn't always makes it right.

Wheel bearings usually make a bunch of noise before they get bad enough to cause the symptoms you are seeing. That it is happening with another set of tires would eliminate a tire issue. I'm assuming the shop checked the wheels for straightness (bent wheels).

You definitely have a dynamic issue here - makes it super tough to diagnose. Suspension and steering might checkout statically, but something could be happening at speed.

Interesting - you had the struts replaced. Did the symptoms you had the first time around happen before or after the strut replacement? What brand of struts did you use for replacement? Did you change anything else at the time - end links, spring isolator, strut mount/pillowball mount?

Did the alignment shop check for static ride height? If the height is different than spec, then alignment against that spec would be off. Some shops also align the car assuming just the driver - if you carry a lot of weight in the car or usually have passengers - need to have them adjust for that.

If the tire was showing some unusual wear - then I'd suspect the struts. With just vibration - hard to say, could be any number of issues. Might have to expand the scope of the diagnostic - could be a bad power steering pump or bad pulley, could something related to the serpentine belt tensioner, excessive body motion, etc.

Hub runout issues were pretty common is some models. Sometimes, they have to balance the tire on the car - though not many shops carry that kind of equipment.

Ouch - blued rotor, must have gotten pretty hot. Hopefully that fixes your vibration at speed - as the other possibilities are much more time consuming, diagnostic-wise.

Well, a stuck caliper can cause all sorts of issues. If the rotor is badly blued and physically scored, it could have cause the vibration at speed - pad sticking to the rotor, rotor is warped enough that it is actually making strong contact with the now stuck caliper. Can cause a wicked shaking at the steering wheel, vibrations can be felt through the floorboards pretty easily.

Sometimes, you can drive a car at low speeds without seeing any issues with a sticking caliper. Some stick then release - so all seems fine. Some stick and cause heavy pulling to one side or another.

The tire shop should have caught that - as they pulled the tires off the car. But then again, depends on the experience of the tech - some don't want to bring up any issues because they are afraid that customers think they are trying to up-sell them on services or plain just don't care.

Sweet! Thanks for the updated post - good to hear it was just the stuck caliper, easy - inexpensive fix compared to the other stuff.