The old tires were Michelin MXV4-Energy, or some such, and with enough treadwear that I am sure they applied some preload to the bushings. There was no shimmy through the steering wheel.

The old tires were a non-stock 195/65HR15 size, and the new I had installed friday are Kumho Ecsta HP4 716 in 195/60HR15, stock rims. With the new tires, steering is lighter and the car doesn't wander on crowned roads, but some vibration/shimmy sets in above 50 mph, and starts lessening above 70 - gone by 80 mph.

My hope is that the tires were not well-balanced, and rebalancing will solve the issue. I know, though, that some seem to solve the problem by replacing the steering damper. Would this be recommended by 105k mi? The idler bushings were replaced, and no looseness noted in the front suspension/steering. Any thoughts?

Steve

I would get the tire balance re-checked, before you go on a wild goose chase.
Sometimes, the installer gets carried away with lubricant on the beads & the tire could actually shift a little on the wheel, throwing off the balance.

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2007 C 230 Sport.

It's very easy to remove the steering damper and check it by stroking. It should offer near uniform resistance throughout its range of movement. For sure it there is any evidence of leaking, it should be replaced. They cost about forty bucks at the dealer.

Unbalanced tires generally cause a mild to moderate "shaking" at the steering wheel. A "shimmy" is a sometimes violent wiggling back and forth of the entire front end, and a bad steering damper combined with poor wheel balance or a tire out of round situation can cause a rather violent shimmy on 201s. Happened to me a couple of years ago - bad damper and out of round tires (had the tires analysed on a Hunter 9700) - replaced both the damper and got an adjustment from Dunlop on a new set of tires.

Duke

Manny, rebalancing will be my first step - I'm a little suspicious because one front wheel has no balance weight on the outside. That's scheduled for wednesday.

Duke, this is mild shimmy - but unpleasant. Just a vibration felt at the steering wheel, where there was none with the old tires. Nothing suggesting it might get worse, but I don't want to ruin brand-new tires. Maybe I'll slip off the damper tonite and check it.

Steve

Hopefully you'll find the problem in the tire itself. If normal dynamic balancing does not solve the problem you may try a Hunter GSP 9700 wheel balancer. Ask the shop to give you the "roadforce score". I've had tirerack replace tires because this score out of range for an acceptable tire.

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Brian Toscano

All I had time to do last night was swap the left front and rear tires. The front had a small weight on the inside - none on the outside. The rear had a larger weight on the outside - none on the inside. Maybe the shop was running low on weights?

Anyway, the car still had the vibration - it's only slight, but compared to none at all before, unacceptable. My appt for rebalance is tomorrow night, and I'm going to insist they let me see what the machine says about weight placement. Even a static balance would be better than improper axial weight placement.

If this doesn't solve it, I'll have to shell out more bucks on a Hunter balancing elsewhere, I guess.

Steve

Steve,

There is another possiblity, I'm not sure how common it is. Lifting the car off the ground and setting it back down again to change the tires may have jarred a weark or loose part in the suspension. But overall it takes moving parts to cause a vibration and the rest of the suspension will transmit it to some degree.

Good luck,

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Brian Toscano

Update. I hovered and hounded at the tire place, and made them redo the rears, too, which they hadn't wanted to. The rebalance seemed to do the trick, as I didn't note any problem driving to work this morning, with a brief burst up to 75 or so. The Kumhos are sure grippier than the old MXV4s, though probably not a fair comparison at this point. Quiet and smooth riding too, and much better directional precision.

One question - when originally putting on the new tires, the store lost one of the plastic trim caps on a lugnut. Are these available from any source?

Steve

Update and question - after a little more freeway driving now, I have decided the problem is not gone, but it is better. The shimmy in the steering wheel is very slight from about 60-75 mph, but still noticeble. You do not feel anything seat-of-the-pants.

I also have noted more response to crowned roads than I would like - the car drifts to the right. It does not pull on perfectly level surfaces. The recent (<20k mi) alignment was farmed out from the shop where some other work was being done, and was with the old tires. Does it sound like it needs to be redone with the new tires, and could this also affect the slight vibration I feel? Thanks.

Steve

Aside from technical issues, I find it hard to believe people take a Mercedes and put Hundai tires on them.

Tires are probably more important than the state of your suspension. Real hard to improve a suspension enough to overcome even the slightest tire irregularities. They are black and they are round but they aren't all Mercedes quality tires. No matter what the salesman says.

I find it interesting the way sales people promote the cheap tires. The buyer might see this as honesty. The buyer just doesn't know that Michelin has not been "Home Depoted" yet. This is a tern I apply to the marketing systems used by Home Depot/Walmart/etc. They have so much influence over suppliers that they turn quality manufacturers into junk merchants; lowering the quality of everything that is available.

A tire saleman probably makes more money off that 50 dollar tire than a hundred dollar Michelin. That is the basis for most tire store recommendations. That and invntory costs.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Steve

Your right on the money with that comment "Home Depoted" I find so many products quality falling by the wayside in favor of increased sales.

Actually, although the Kumhos are cheaper than the Michelins, the principal reason I chose them is because they were reviewed to be superior in snow - and superior in that regard than the rest of the all-season designs. In addition, purchasers preferred them to the MXV4's in all the reviews I read, as far as I could tell. In this regard my experience with the Michelins is unimpressive. Here our excursions in the winter require driving steep, icy mountain roads with no room for sloppiness, and deep snow on the roadways.

Having owned MXVs or MXV4s on almost every vehicle I have owned since the late '70s, I am very familiar with them. I have directly compared them to Pirelli, Yokohama, Bridgestone, Remington, and now Kumhos. They are great tires, but in whole have not in my experience lasted any longer nor had any fewer balance/alignment problems than these others (Pirelli being the bad apple, so far).

As far as the current situation, the Kumho's definitely are outperforming the Michelins in all respects, pleasantly, and I am not prepared to attribute that to anything more than that they are new and a lower profile. However, tire vibration problem I also had with the Michelins, until I swapped those front/rear.

Perhaps it is different in FL, but most of the Michelins sold in SoCal seem to be made in Brazil or France, which also seems to have more to do with quality than manufacturing method. I have rejected Michelins in favor of other brands in the past because of poor quality appearance on casual inspection. I used to buy exclusively Michelin due to presumed higher quality. Now I expect them to prove themselves against the competition.

Steve

The attributes that promote good all weather handling and those that permit endless smooth driving are at opposites with one another. So if you need an all weather tire M+S, michelin may not be for you.

Drawing conclusions on tire performance is real hard if your experience is wear one set out and then buy another. You always wind up comparing the worse state of the previous set with the best state of the current set. Align 2-5 cars a day for 30 years and comparisons have meaning.

I wouldn't consider a poll taken on tire performance from individual owners for these reasons. I also wouldn't consider a poll unless the tires were free to start with. The publics ability to judge the money in their pockets is definitely better than their ability to judge the quality of rubber they are riding on. Take a poll of alignment techs and I might listen.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

"Drawing conclusions on tire performance is real hard if your experience is wear one set out and then buy another. You always wind up comparing the worse state of the previous set with the best state of the current set. Align 2-5 cars a day for 30 years and comparisons have meaning."

I agree - so I have to go with what I've got - consumer reviews. The last car I owned was my Integra, and I had a greater variety of tires on that in 180k+ miles than the rest of the cars combined. It handled well, but neither it nor the route I travel were kind to tires. The Michelins were a very good overall balance, but not the best in any particular category except comfort.

Anyway, back to my basic question - is it reasonable that the alignment I had with the old, worn tires could be incorrect for the new ones? I.e., if the old tires had a tendency to pull or wander due to uneven treadwear, would the alignment have been adjusted to make the car track better?

Please note too that ALL the effects I have noted are slight, and all the suspension bushings front and rear are original in this '91. Thanks.

Steve

Anyone?

Steve