Just wanted to let you all know that for those of us who have had the slight steering wheel shake/shimmy at highway speeds, that Toyota released a TSB this December. If this isn't news to anyone, let me know, I'll delete this one to not clog up the forums. My searches didn't net any results.
Service Bulletin 368419 for Toyota STEERING | AutoMD
I have had a slight shimmy at 55-70 felt only in the steering wheel since about the 1st mile I put on the FJ. I did have AT's immediately put onto my FJ when I bought it, and I assumed from day one that the issue was with the tires.
I went into discount tire at 500 miles, and they found all tires were well balanced. The Discount Tire guys up here in MN have always treated me well, and this time was no different: they went the extra mile by road-force balancing them just to be sure nothing was off. The tire/wheel combo was in sync, and everything seemed great. I was thrilled until the shimmy returned 200 miles later, but it wasn't noticeable, and I easily ignored it. After a few thousand miles it went away. I figured it was, again, the tires - coupled with a very sensitive FJ cruiser, and chalked it up to the tread wearing down a bit. It would come and go, and any time the tires were rotated it would come back pretty heavily but fade away after another thousand miles or so.
I just went in to Toyota for a tire rotation, and mentioned the issue to the technicians (I bring it up in passing every time I'm in to see if a different person has thoughts on it). The service manager dug around and came up with the TSB released a few months after my last tire rotation. We went out for a test drive, and the vibrations I dealt with the whole way to the dealership had vanished. I was disappointed to not be able to show them what was going on, but we decided to rotate the tires and then test it again. Sure enough, after the rotation the vibes were back and the service manager ordered the parts for the TSB.
They had it for a few days, and while I would have been hesitant to drop the FJ off knowing the scope of the labor and dis-assembly it would be going through, I am really happy to know that the issue was recognized and that these steps may correct it. The technicians, advisors, and managers at this dealership are phenomenal, and I have (and will) continue making the longer drive to use them.
UPDATE: This job sounds like it was a hell of a lot of work. The service adviser, and the manager there both stated it was a PITA for the technicians involved, but that they got it taken care of. With the FJ back I can say that the shimmy seems to be mostly gone at speeds under 60mph.
: I did have a chance to drive it at, or over 60 mph today for quite awhile, and low and behold, I still have a shimmy. I noticed CBNG also had a slight vibe which he states he left it to the dealer to correct. I'm going to be bringing mine back in next week for another appraisal.
: The FJ went back to dealership. They confirmed the exact same vibration felt before the TSB was performed still exists. They are trying wheels/tires from another FJ, and are going road force balance again to see if it responds differently.
: Dealership road-force balanced the tires again. They did a very good job, but there was a slight shimmy still felt. RFB showed one tire with a value at around 20. After researching the Michelin LTX's and what other people are running them at, as well as comparing the specs on them to the TT's BFG's, I found that running them at the stock 32 PSI cold was just too low. I bumped them up to approximately 37PSI all around and the vibration is almost completely absent.
: I've been running the FJ about 1200 miles since the final RFB and have found a happy medium of 37PSI front 34 PSI rear with the Michelin's listed in my signature.
Lessons learned: Ask whoever is balancing your tires the last time their RFB machine was calibrated. FJ's are sensitive - so ask them if you can see the RFB numbers. Tires that aren't usually considered out of round, might actually be causing an issue for your vehicle. Try slightly bumping up tire pressure - look up "chalk testing", and use it to ensure you aren't over-inflating and causing incorrect wear. The door-jam recommended pressure is ONLY proven to work for the stock dunlops the FJ comes from the factory on. Don't assume it works for your FJ or new tires.