Vibration in car after new tires and front struts

February 8, 2021 8:52 PM

Last fall for my 2008 Mazda 5, I got a set of four new tires, and shortly afterwards replaced the front struts. I haven't been driving a lot these days, and when I drove on the freeway recently at about 60mph/100kph I noticed a vibration that can be felt both by the driver and the passenger. It's not excessive, but it's noticeable. Is it likely a tire issue, or a struts issue?

I'd like to know whether I should go to the tire shop or where I had the struts replaced to have it looked at.

The tires were replaced because not only was it their time, but also sped along by jumping a curb and hitting a rock and tearing a hole in a sidewall. The struts got replaced as the rock caused alignment issues, and the shop that did the alignment suggested I replace the front struts (which wasn't an unreasonable thing to do in a 12-year-old car).

Given how little (that is, next to none) freeway driving I've done, I didn't notice the vibration immediately after the work was done.

posted by ShooBoo to Travel & Transportation (11 answers total)

Well, I have a Mazda3 that I bought new in 2007. A couple of years ago, I had the dealer put my snow tires on. After that, when I drove on the freeway there was a very distinct vibration. Turns out a lug nut was missing! Apparently, the technician had cross-threaded a lug-nut, rendering it useless, and didn't want to fess up to his supervisor about it, so he just left the lug nut off (not a safe thing to do). I demanded a refund, and got it, and then took my car elsewhere to have a new lug nut installed, which cured the vibration.

A more recent issue that caused my car to shimmy only on the freeway was that it needed new tie rods. From the internet: "A tie rod is a device that links your car's steering knuckle to the steering rack on the front wheel." Tie rods replaced, and car drives smoothly as a dream now.

Don't know if these things are what is happening with your car, but they could be two possibilities.

If it were me, I'd take it to a reputable shop that can look for any issues in general.
posted by SageTrail at 9:49 PM on February 8, 2021 [1 favorite]

Edit: It needed new tie rod ends.
posted by SageTrail at 9:57 PM on February 8, 2021 [1 favorite]

Vibrations at a resonant speed might just mean a wheel needs balancing. That's a cheap thing to get done at most places.

If it doesn't work you'll know, and if there's a problem they spot while they're doing it they will tell you, especially if you ask them to keep their eyes open.
posted by How much is that froggie in the window at 10:06 PM on February 8, 2021 [2 favorites]

First guess is that you may have lost a wheel weight. A rebalance should do it. A lot of times, wheel balance issues will have a sort of resonant speed where, for example if you drive exactly 63mph, the vibration builds and builds, but if you drive 60 or 66, it is far less noticeable.
posted by xedrik at 10:08 PM on February 8, 2021 [3 favorites]

I agree that this is likely to be a wheel balancing issue. Lost wheel weights are one cause of these, and it's easy to fix if that's what it is, but the same rock that tore up your sidewall and shifted your alignment might also have put a ding in your rim and made that wheel a bit less round.

This can cause vibration when the wheel's rotation rate matches the suspension's resonant frequency, even when the affected wheel is well balanced enough not to vibrate on a balancing jig, and the only real fix is to replace the dented rim. The workaround is to switch that wheel with the spare.
posted by flabdablet at 10:46 PM on February 8, 2021 [1 favorite]

Agree with the above - first thing first is to get the tyres inspected and rebalanced. If the vibration is still there, then look at more serious things like ball joints or tie rod ends. It is unlikely to be a strut.
posted by Brockles at 5:11 AM on February 9, 2021 [1 favorite]

Adding support for the suggestions of a wheel balance issue . . . if the tires have been balanced already, they might need high speed balancing or road force balancing too. If your shop can't detect it, ask them to have the guy accompany you while you drive and the tech sit in the passenger seat with you. You might have to pay for the guy's time while he rides with you.
posted by dlwr300 at 5:35 AM on February 9, 2021

It's a balance issue, likely in the wheels and tires. The strut replacement would have almost no bearing on a resonant vibration.

When they replaced your tires, they had to re-balance each wheel/tire combination. Either one of the wheels wasn't balanced correctly, or one of the weights didn't stay put.

Go back to the tire shop. Explain that you've driven very few miles since the new tires were put on (they'll be able to see the elapsed mileage) and that you've not been on the highway enough since then to notice the problem. Demand that they re-balance the wheels.
posted by notsnot at 5:41 AM on February 9, 2021

I repeat that a tire balancing may be in order. I would also have the alignment checked again. Was it done after the suspension work was done?

Get it done soon as the vibration could cause your new tire to quickly wear unevenly.
posted by tman99 at 8:16 AM on February 9, 2021

I agree it that it is likely a tire balance problem. Do you feel the vibration through the steering wheel? That might help determine if it is front or rear wheels. But you may as well have all four rebalanced. The tire shop may do this for free.

Also have the tire shop carefully inspect the tire for possible belt or tread separation.
posted by JackFlash at 9:37 AM on February 9, 2021

Depends on whether the vibration is speed dependent, i.e. do they speed up or slow down along with your car. I know, captain obvious comment. But really, that's the first thing to check. As that will narrow down the possibilities. I would have thought they had balanced the wheels after putting on the new tires, but it would not be unreasonable to balance them again, as they need to take the tires off to check for other stuff, such as tie-rod ends and such.
posted by kschang at 12:57 PM on February 9, 2021