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Shaky front end repair

This is a bit of a long post, but stick with me. Recently my wife and I took a weekend trip to PA. We drove my Malibu Maxx with about 130K miles on it and with no obvious driving issues of any sort. After our first day I noticed there was a slow leak in one tire. The next day I took the car to a national auto/tire repair shop. They diagnosed my leak as needing a new valve stem which they repaired for twenty bucks and sent me on my way. Now the story gets interesting.

As soon as I got on the interstate and got the car up to 45 mph the front end start shaking violently. I pulled over thinking the tire had gone flat, not so. I called the shop and drove it back in to them. They look at it further and said the wheel they repaired was bent and this was causing the shaking. Now I had taken a hard it on a trip about three years ago, but had not had any wheel trouble. When I asked why the car would start shaking so bad now when it never did before they had no good answer, but said they would examine the suspension for other issues.

They look at the suspension and come back and tell me the bushing on the lower control arms are bad. They have the car up on a lift running and I can see the wheel wobbling. They give me a @$300 quote to do the bushing and tell me to come back the next day since they could not get parts on a Sunday.

I return the next morning and now I am told that they cannot replace the bushing because the control arms are aluminum, they have to replace the whole control arm and the cost will be $800. While I am feeling skeptical at this point, I am out of town and need to get the car fixed. So they do the repair. (FYI, I find out later that the bushing are replaceable)

I get in the car and get on the interstate. When the car gets up to 60 mph the front end starts shaking, not as bad as before but enough to have to back off the speed. I drive back home and take it to another branch of this national chain. They say the shaking is coming from this bent wheel. I have them move the wheel from front to back and it seems the shaking does move with it. Here are my questions, remember that I drove into the shop with only a leaky tire:

  1. Is it possible that the bushing would fail so suddenly that I would have no warning, so that it was just a coincidence that they failed after getting the tire fixed?

  2. The shop claims that it may be the dealer best practice to not replace the bushings but rather the whole control arm, I am going to verify, but does anyone know?

  3. If the bushings did indeed go bad and led to the first shaking, why is the bent wheel now showing a shaking when it did not before?

  4. One theory the shop gave me for question 3 was that the failing bushings were absorbing the wobble from the bent wheel so it masked the problem until the bushings completely failed. Is even remotely possible?

As you can imagine, I am very frustrated that I drove into get a simple tire repair and drove out with an $800, a shaking at high speed and a ruined vacation.

Wow. These guys shure can shovel it.

The reason your wheel was wobbling was because they popped the bead, changed the valve and didn’t rebalance the wheel. I can tell by the price they charged you.

Everything else from there on out was pure, unadultrated, BS.

Im sorry to hear you had this experience. It’s an embarassment to the industry. It gives all shops a bad name.

I am having that independently checked out. I admit I did not asked if it was balanced after the repair, although I seem to remember them saying they did. I do know they did not do a front alignment after the control arm work - even the second shop said that would be standard to do that.

While I fully agree with TSMB that it was not balanced, it is quite possible that the rim is bent, the tire shop might have bent the rim when they broke the bead. You need to jack up the car, or put the car on a lift and rotate the tire at LOW speed to see if it wobbles. You usually need a dial indicator mounted on a magnetic base to detect the wobble.

Control arm bushings do not go out on a car this new. The rubber “checks” and it looks bad, but it is not. Mechanics like to show this checking and use it to scare customers into unneeded repairs. It is true that in many cars, you replace the whole control arm, whether it is aluminum or steel instead of just the bushing.

Digging a bushing out of a control arm can be very labor intensive so it can be cheaper to just replace the whole control arm, much the way mechanics often replace the front axles when the CV boot gets torn.

I vote with the same mountainbike. Your vehicle wasn’t vibrating before you had the valve stem repair. If the tire was installed in a different position in relation to the wheel after the valve stem was replaced, then the wheel needs to be rebalanced.
I had a similar vibration with my 1978 Oldsmobile when it was 28 years old. When I got up to 40 mph I had a terrible vibration. When I investigated, I found that the weights on the right front tire were sliding around on the rim. I removed the weights and that reduced the vibration considerably. I was going to go to my independent tire shop, but found a receipt in the glove compartment from WalMart where I had purchased the tires ten years earlier. On the receipt was a guarantee for lifetime balancing. I took the car to WalMart’s service department. The service manager asked what problem I was having. I described the situation, and then added that I was coming back to town on the interstate and a Ferrari came abreast of me. I didn’t want him to get ahead of me, so I floored the accelerator. I said that it vibrated so badly at 110 mph that I had to drop back and was really embarrassed by the Ferrari. The service manager looked at my old Oldsmobile 4-4-2, looked at me, shook his head and said, “Maybe I had better rebalance both front tires”. He honored the warranty.

Great story!!

It’s also possible for a tire to become unbalanced just from the sheer act of breaking the bead and inflating it again even if both rim and tire are marked beforehand and kept in the same orientation.

As to the wheel wobble I might suggest this. You state the car took a hit a few years back and this could have bent the wheel rim and wheel hub. Maybe what more than likely happened here is that the wheel was installed in a different position on the lugs from the way it came off of the car.
The different orientation of the wheel on the hub could have caused a previously unnoticed problem to suddenly appear and become more noticeable than it was.

If the car were mine I’d put a dial indicator on both hub and wheel and find out for sure. Hope that helps in some way.

All of these responses help a lot. I am trying to put together a logical scenario of why I was told I had two new problems that I never had when I drove in the place.

I have taken the car to an independent mechanic who now says I have a mis-shaped tire. I am going to try a couple of new tires to see if the problem goes away. At least I can give the tires back if it does not. He is also checking the balance on the suspect wheel.

Rely on the advice of the guy ooking at it jands-on, but if he suggests “indexing” the tire, which basically places the tires heavy spot (they aren’t perfect) opposite the wheel’s heavy spot, be aware that this is a common way of addressing this type of symptom and is perfectly acceptable. It makes balancing the wheel much more successful.

Good luck.

Sorry, mountainbike, but indexing refers to the uniformity high point of the tire being matched to the uniformity low point of the rim. (Unifomity? Think run out and you will be close). The net effect is a more “round” assembly. This is totally different than balance.

Besides, once you balance a tire, it is balanced. It doesn’t matter where you start - the end result is the same - a balanced assembly.

But I was going to suggest that the tire might be separated - and that the OP should look for a bulge. The clue was the valve stem repair. Why do that if it wasn’t leaking - and if it was leaking, the tire would have been under-inflated.

But I am surprised no one suggest rotating the tires to see if it changes. That would eliminated either the tires or the vehicle as the souirce of the problem.

Thanks to everyone for you comments. They have helped me to put together a reasonable scenario of what happened.

First of all, my independent mechanic said the dent in the wheel is not enough to cause the second case of shaking. He examined the tires and discovered two of them were mis-shaped; they were not flat across the service but angled in. The tread is still about 50% and I rotate regularly, but I guess this happens. So we put two new tires on the front, keeping the dented wheel in the back and voila, the car drives as smooth as ever. Like a good CSI show, here is now what I think happened.

I go into the shop with a leaking tire, which they fix, but do not balance the tire. I get on the highway and have violent shaking because of it. I go back to the shop, they probably realize that the tire was not balanced, but someone does not want to admit that. In the meantime they balance the tire. Because someone is covering up the failure to balance they have to give me a reason for the shaking. The dent in the tire is a good place to start. So they tell me I have a bad wheel.

When I question that I have been driving on that wheel for years that way, they need to come up with another reason for the shaking other than the out of balance. They put the car on the lift and show me the with a wobble and the control arm bushings checking. The bushing were not bad, worn but not failed. I bought into their ruse and said fix the bushing, which morphed into a control arm replacement.

Now, why did I have a second case of shaking at a bit higher speed that was not there before? When the suspension was tightened up with the new control arms, the vibration from the mis-shaped tires showed itself. The vibration was being masked by a looser suspension. The car was perfectly driveable under the conditions with worn but not failed bushing and the tires. Those would have eventually been needed repairs.

The key points you guys help with was that it had to be an out of balance tire that started the whole thing, along with the tip that mechanics like to show of checking in the bushing as something in dire need of repair. Thanks for the help.

Now I move on with the battle with the shop to get my money back.

I stand corrected. Thank you Capriracer. It’s good to have a tire expert looking over my shoulder.

Dent in the wheel? It is true that a small dent in the rim of a wheel is not going to cause vibration, but that dent can be an indicator of a larger problem. How did the dent get there, did the tire shop put it there when they dismounted the tire to install the valve stem? If so, the dent is not the problem.

The wheel is being held in place at the center by a cone of some type. The breaker bar comes up and hits the edge of the wheel (the rim or lip). It pushes up ward on the wheel, not just putting a dent in the wheel, but also throwing the plane of the wheel off center. This is why the wheel has to be mounted and the tire rotated slowly by hand with a dial indicator checking for runout of the wheel.

Maybe all this didn’t happen, it’s just one theory, but until you or your mechanic uses a magnetically mounted dial indicator on the wheel to measure runout, you will not know.