sdwtchlvr

iTrader: (1)

So I have been noticing a shimmy/bouncing at highway speeds (between 60-80mph) for a couple of months. It started right after I had a local indy tire shop swap my sliver stock wheels for the chrome version of the same wheel I picked up locally.

Funny thing is I did my front brakes last Sunday and after putting the tires back on, the ride felt smoother at highway speeds. I figured perhaps the indy shop didn't torque the wheels properly (which I'm sure they didn't as they didn't ask me the torque spec and didn't look it up, and used an impact gun to tighten bolts). I torqued my front wheels to 103lb by hand after doing front brakes.

This Thursday, I did my rear brakes and torqued the rears to 103lb. On the highway the shaking/bouncing is back and dare I say more noticeable.

Could it be that I did something incorrect when installing the rear wheels? The tires are Michelin Pilot Sport A/S 3 with about 15k miles on them. Look to be wearing evenly.

I have an appt. on Monday to have the tires balanced at Discount Tire. I asked about their machine and he said it's a Hunter which I take to me Hunter Road Force balancing machine. Is there anything particular that I should ask or know prior to going in?

Dave Mac

The Discount Tires I go to have Hunter balancing machine but not Hunter Road Force balancers which are preferred of course so you might ask further.

Also I didn't think 103 ft. lbs. was the Lexus wheel torque spec. - something more like 76 ft. lbs. I thought.

Dave Mac

sdwtchlvr

iTrader: (1)

Ah, Ok. I'll inquire. I figured that since they had the Hunter balancing machine that it was by default a road force machine.

I remember reading that it was 103lb. But I could be wrong. I'm sure other's will chime in.

sdwtchlvr

iTrader: (1)

Just got off the phone with Discount Tire. They use a Hunter Match Force machine, not a road force. The DT employee who answered the phone referred to the Road Force machine as a Ride Match or Ride Force, I can't remember which now. lol But he said they haven't used that machine in approx 6 years. He went on to say that the Ride Force machine was very time consuming and involved dismounting the tires and then matching a specific spot on the tire to a specific spot on the wheel.

He says the Ride Match machine works very well and should be just fine. Seems ok to me. They quoted between $15-$20 per tire.

sdwtchlvr

iTrader: (1)

Just checked tirerack.com and you can search installers that have road force balancing. Called a Firestone location here in town and they have the Road Force 9700 unit. $63 for all four tires. Going there tomorrow morning. Hopefully I'll be riding smooth after that.

Nospinzone

That's the way to go.

caha14

It is 103 ft-lb, "officially" 140 Nm, since Lexus, being Japanese, uses the Metric system.

There is no such thing as a "Lexus wheel spec"... Most sedans have a 113 mm bolt pattern, and many of those (if not all) are 76 ft-lb, but LS 460 has a 120 mm bolt pattern, larger studs, and thus, a higher torque spec.

Dave Mac - time to go tighten up your lug nuts!

Hunter has been in business making balancers for a long time, so indeed, it's always a good idea to ask if they have road force. Even if they do (and I hate to always be the one saying this), there are no guarantees. From machines out of calibration, to worn mounting adapters, to utterly clueless operators (at independent shops and even at my former dealer), I could fill a couple volumes with the stuff I've seen/dealt with over the years. Ultimately, the machine will produce results only as good as the quality of the work that is performed, beginning with properly-centered, repeatable mounting of the wheel and tire to the machine.

Along these lines (I forgot to properly "quote" your last message), there is not much to lose with the people you spoke with, but $63 is very low for a balance job, never mind road force. Some shops will "eat" the cost, but bear in mind that a proper road force balance, under normal circumstances where some tire-to-wheel adjustments are needed, etc., will take time, typically costing at least twice that much. I don't mean to discourage you from trying them out - just trying to be a bit realistic, based - again - on past experience. I hope it goes well, and please keep us posted!

sdwtchlvr

iTrader: (1)

That makes sense. I wasn't too confident in the guy at the last shop I went too. It was a little hole in the wall tire shop that swapped tires/wheels from 2 different sets and balanced them both, then mounted the chromes on my car...all for $80. There is a lot of these types of shops in SD....a ton.

I'll speak to the manager when I go in tomorrow and ask about when the machine was calibrated last and about how it's performed exactly. I don't want to come across as a pr*ck but I'll have to word it as friendly inquisitive. Definitely agree about the tech knowing how to use the machine. He said they have two balancing machines, the road force and another one and he made it seem like the road force was newer and they just got it in.

caha14

That sounds like a plan! I'm hoping for the best. The process is just more nuanced than it used to be in the days of steel wheels.

For instance, there are different kinds of mounting hardware, some of which are considered optional, that do produce a truer, more repeatable mounting: mounting cones, collets, flange plates, etc. As an appetizer, Google 'Haweka Adapter Plate'... Most Lexus dealers own these, and it may be a dealership-required tool from Lexus (as is the GSP9700 at this point).

When a tire is balanced on a well-calibrated machine, taken off the machine, put back on, and the machine reads zero again, that's a thing of beauty.

AznRacer

iTrader: (2)

Everytime I need to get my wheels rebalance I always look for places that do road force balance. It make a big difference. I use hunter website to locate a shop that have their road force balancer.

http://www.gsp9700.com/search/findgsp9700.cfm

NickTee

I've said it in a couple threads, with good reason, but make sure your mating surfaces are clean. Even if it doesn't look like it, taking a wire brush drill attachment to the mating surface on the wheel reveals exactly how much brake dust and oxidation has actually accumulated on the mating surface.

sdwtchlvr

iTrader: (1)

Good point. I cleaned the hubs with a wire brush on a drill and the rotors were new. But I didn't even think to clean the inside of the wheels where it meets the rotor. I'll ask the guys at Firestone to make sure the surfaces are clean.

Dave Mac

Dave Mac - time to go tighten up your lug nuts!

That got my attention since I have used 76 ft. lbs. for at least the last 15 years but the problem was I had drifted over to the LS forum without paying much attention. 76 ft. lbs. is the spec for the ES350 that I have - and will be replacing with a 2016 next week. I haven't had an LS since 2000.

Dave Mac