Back seat vibration on a '10?

[dividedsky319]

I've read all the tire/vibration threads to death, and am just wondering if anyone with a 2010 5 has had vibration issues...

I had the dealer look at it once and they checked the balance and said it was fine, the tech took a ride with me and basically said it's normal and it's how they drive. So, I kinda got used to it, but the past few days I've noticed when looking at my daughter in her car seat in the second row, I can actually see her shaking a little bit (at 45mph and above). She's only one so she can't exactly tell me how bad it is, and I personally haven't ridden in the back seat yet.

It only has 1.2k miles on it, I took it into the dealership with only 600 miles or so on it. AFAIK at the dealership they only checked the balance, not the alignment, maybe I should bring it back in and have them check that... but the guy was pretty adamant about nothing being wrong. Of course we were sitting in the first row...

Any suggestions what I should do? And if I do bring it back to the dealership to have them look at it, what I should tell them to do? Check the camber/toe?

 

[Heat]

I was wondering about the shaking when I first bought my Mazda5 in February '09, here is a thread which includes a youtube video of the shaking seat:

http://www.mazdas247.com/forum/showthread.php?t=123734349

It's just one of those things with this vehicle though whenever somebody with weight sits back there it doesn't shake. Try sitting back there while your wife drives, I don't think you'll feel anything.

 

[Mazda5wannabe]

I had the shake too, until I replaced the OEM tires. Hasn't been an issue since.

 

[Robotazky]

Mine does it. I hate it. The steering wheel nibbles, too. I have $800 worth of Michelins, road-force balanced three times, and it still shakes.

 

[theprotege99]

Bad shock absorber would be my next guess.

 

[Robotazky]

I've assumed that the cross brace that mounts under the seats, across the bottom of the car (forgot the maker) would help with that. Not sure though.

 

[mazdadude]

OK,

1. Balance tire - done
2. Examine wheel for warped dented wheel -
3. Examine the mounting faces between wheel and hub/rotor -
4. Examine shock absorbers for possible oil leak -
5. Spin each tire while mounted on the vehicle and observe carefully for any hop or wiggle to the tire.


#5 was what finally isolated my problem, I had a tire that looked 100% ok on outside, and it balanced fine, but when you spun it while on the car, the tread had a hop to it. Took the tire off the rim, and inside carcass of tire was full of ground rubber. Evidentally the tire was ran low on air, this degraded the inner sidewall to the point where there was less reinforcement, and the area that now had less reinforcement and was into the cords was then allowed to expand more, thus creating the tread hop.

 

[Robotazky]

Unfortunately, mine did this even with brand new tires with less than 100 miles on the car. I've written it off after spending way too much time trying to get rid of the problem.

 

[Heat]

Is it noticable when somebody is sitting in the rear seat?

 

[Robotazky]

If you're asking me, yes. I have sat my own ass in the seat to perform that very test. You can't see it shaking any more, but you can feel it. It goes away more and more as you increase the weight in the back. I think it could have something to do with the shock/spring setup being somewhat overly stiff so that it can handle all of the cargo that it's designed to hold. Like I said, I just got tired of thinking about it and gave the car to my fiancee to drive. She doesn't mind it.

 

[Mark787B]

Ha! I'm in the same boat but my fiancee can't drive stick...

 

[rscottg]

I've read all the tire/vibration threads to death, and am just wondering if anyone with a 2010 5 has had vibration issues...

I had the dealer look at it once and they checked the balance and said it was fine, the tech took a ride with me and basically said it's normal and it's how they drive. So, I kinda got used to it, but the past few days I've noticed when looking at my daughter in her car seat in the second row, I can actually see her shaking a little bit (at 45mph and above). She's only one so she can't exactly tell me how bad it is, and I personally haven't ridden in the back seat yet.....

As soon as I put my winter tires on, all that shaking goes away. Very smooth, but that is with 16" tires instead of the factory 17's. When I replace the 17's, I'm going to try and make sure I found the smoothest/quietest tire for GT tire size and hope something is better than the factory tires.

 

[flcruising]

I've ridden in the back several times and never noticed any vibration. This was fully loaded with 6 passengers on stock Toyos. One of my kids rides back there often and has never complained or noticed vibration.

 

[flcruising]

I've ridden in the back several times and never noticed any vibration. This was fully loaded with 6 passengers on stock Toyos. One of my kids rides back there often and has never complained or noticed vibration.

 

[wmzda5]

I've assumed that the cross brace that mounts under the seats, across the bottom of the car (forgot the maker) would help with that. Not sure though.

+1 I thinkso too

 

[wmzda5]

If you're asking me, yes. I have sat my own ass in the seat to perform that very test. You can't see it shaking any more, but you can feel it. It goes away more and more as you increase the weight in the back. I think it could have something to do with the shock/spring setup being somewhat overly stiff so that it can handle all of the cargo that it's designed to hold. Like I said, I just got tired of thinking about it and gave the car to my fiancee to drive. She doesn't mind it.

The car basically has a huge open space and the body tends to flex as the car turns and twists. Eventually the frame will find its resonant frequency and the vibration will increase. You can minimize this by altering the resonant frquency by using stiffer springs or stiffer shocks. But for those of you who does not want to lower or change shocks there are under body braces available that might help.

Having researched alot of aftermarket parts - I've stumbled upon some suspension upgrades that I was curious anyone have seen / experienced. Obviously lowering / sport springs are popular around here, but there are some other items to minimize body roll, cornering, etc.

For example:
Coilovers - anyone have them? (pricey!)

Autoexec Floor Cross Bar http://www.protegegarage.com/product_info.php?cPath=23_386&products_id=860 At Protege Garage & Cork sport. - anyone know where this mounts exactly? Have much effect? Fairly cheap for suspension parts

Autoexec Lower Front Bar http://www.protegegarage.com/product_info.php?cPath=23_386&products_id=862

Of course there is also a strut bar, Autoexec & others.

Then there is some weirder stuff, like:

Under Body ("mid-ladder") brace: http://www.andysautosport.com/mazda/2006_9999_mazda_5/suspension/arm_bars/gt_spec/gtsc00166601.html No pics - no ideas?

Chasis Under Brace (mazda5 down a bit on page) http://www.motorexonline.com/ChassisUnderBrace.html Pics - but still no ideas!

Love to hear your thoughts on any / all / something not listed.

 

[southpawboston]

we have carseats in the 2nd row, and they shake when our kids aren't in them. i don't think the kids feel it when they're strapped in, and their extra weight pretty much stops the shaking.

i'm also experiencing a very mild (yet annoying) shake in the steering wheel between 65-75mph... i wouldn't expect this on a brand new car with under 1000 miles. i guess i'll mention it at the first service.

 

[Robotazky]

we have carseats in the 2nd row, and they shake when our kids aren't in them. i don't think the kids feel it when they're strapped in, and their extra weight pretty much stops the shaking.

i'm also experiencing a very mild (yet annoying) shake in the steering wheel between 65-75mph... i wouldn't expect this on a brand new car with under 1000 miles. i guess i'll mention it at the first service.

You should give today's tires at least 3,000 miles to break in before you start balancing and all that. First, every time people touch your wheels they get chipped/scratched, or something. Not once have my wheels or car interior come back the way they went in the shop. Maybe I just pay very close attention. I don't know. That said, tires have so much plastic in them now to increase mileage that they have to drive thousands of miles in order to break in if the car sat on them very long. The plastic also makes them louder and harder, but hell, nobody cares anymore if the ride is good because people are so cheap now. It's all about mileage and spending nothing on tires so that the car payment can be higher. *end rant*

I suggest waiting. I've been through this. The more they break in the longer your new balance job will last.