Shakes from 35-70 mph
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,035
Likes: 0
From: Atlanta Ga
Shakes from 35-70 mph
OK, so this is on my 1989 coupe that is only driven about 2K miles a year around town. Car is in good shape at 82K miles but it just shakes too much, a lot of movement in the steering wheel and I'd like to get this solved to make the cruises more enjoyable.
The tires and wheels are reproduction ZR-1 polished rims with Sumitomo ZRII tires. QA-1 adjustable shocks are on but set at one of the softest settings, these have less that 6-7 K miles on them.
Now of course this does sit for weeks at a time but even on back to back days after driving it for 25 miles it still feels the same so I don't see this as flat spots. I don't suspect the balance on the wheel and I can swap front to rear very quickly for a test to rule that out but it was been this way for some time.
What are some other areas to begin looking at??? Steering connections? Ball joints? Tie rod ends? Steering rack? other?
The tires and wheels are reproduction ZR-1 polished rims with Sumitomo ZRII tires. QA-1 adjustable shocks are on but set at one of the softest settings, these have less that 6-7 K miles on them.
Now of course this does sit for weeks at a time but even on back to back days after driving it for 25 miles it still feels the same so I don't see this as flat spots. I don't suspect the balance on the wheel and I can swap front to rear very quickly for a test to rule that out but it was been this way for some time.
What are some other areas to begin looking at??? Steering connections? Ball joints? Tie rod ends? Steering rack? other?
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
It could be some of the other areas you mentioned, however, most of those will have a presence across a wider MPH range.
I have experienced this in my car a couple of times, vibration and shaking at certain mph ranges. Both times it was fixed with new tires, oddly enough both times were when the car was wearing Sumitomo's. However, it never sat for weeks at a time. I calculate that if driven around 2K a year, then these are about 3-4 years old. If they sit for a long period, yes the steel belts inside the tire can warp and cause this.
Before springing for a new set of tires, try taking it in to get the tires rebalanced. If they have a hard time balancing, I would say it's new tire time.
If it were steering related, I would think it would be more present during turns at lower speeds. If it were suspension related, it would be more present at turns curves during higher speeds. If it were brakes, rotors obviously during braking. But vibrations at specific speeds in a straight line are almost always tire/alignment related.
The one exception to the above might be if the drive shaft were off balance, the u-joints/half shaft joints were going out. But you'll get the tell tale clicking and clunking with these as well.
I have experienced this in my car a couple of times, vibration and shaking at certain mph ranges. Both times it was fixed with new tires, oddly enough both times were when the car was wearing Sumitomo's. However, it never sat for weeks at a time. I calculate that if driven around 2K a year, then these are about 3-4 years old. If they sit for a long period, yes the steel belts inside the tire can warp and cause this.
Before springing for a new set of tires, try taking it in to get the tires rebalanced. If they have a hard time balancing, I would say it's new tire time.
If it were steering related, I would think it would be more present during turns at lower speeds. If it were suspension related, it would be more present at turns curves during higher speeds. If it were brakes, rotors obviously during braking. But vibrations at specific speeds in a straight line are almost always tire/alignment related.
The one exception to the above might be if the drive shaft were off balance, the u-joints/half shaft joints were going out. But you'll get the tell tale clicking and clunking with these as well.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
Tires have a "use by" date just like ground beef. If they are rarely used, then FLAT SPOTS will appear whether you believe it or not.
Its often referred to as "out of round", but its the same basic thing....the tire has been ruined from sitting for too long AND as the rubber ages it hardens and becomes less pliable and able to conform to the road surface...."use by date" is there to protect against dry rot and other structural damages that comes from age.
Its often referred to as "out of round", but its the same basic thing....the tire has been ruined from sitting for too long AND as the rubber ages it hardens and becomes less pliable and able to conform to the road surface...."use by date" is there to protect against dry rot and other structural damages that comes from age.
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 113
From: Michigan
If it is flat spots http://flatstoppers.com/ Or just move your car every once in awhile, just be sure to let the engine warm up.
Instructor
Joined: Aug 2013
Posts: 121
Likes: 3
OK, so this is on my 1989 coupe that is only driven about 2K miles a year around town. Car is in good shape at 82K miles but it just shakes too much, a lot of movement in the steering wheel and I'd like to get this solved to make the cruises more enjoyable.
The tires and wheels are reproduction ZR-1 polished rims with Sumitomo ZRII tires. QA-1 adjustable shocks are on but set at one of the softest settings, these have less that 6-7 K miles on them.
Now of course this does sit for weeks at a time but even on back to back days after driving it for 25 miles it still feels the same so I don't see this as flat spots. I don't suspect the balance on the wheel and I can swap front to rear very quickly for a test to rule that out but it was been this way for some time.
What are some other areas to begin looking at??? Steering connections? Ball joints? Tie rod ends? Steering rack? other?
The tires and wheels are reproduction ZR-1 polished rims with Sumitomo ZRII tires. QA-1 adjustable shocks are on but set at one of the softest settings, these have less that 6-7 K miles on them.
Now of course this does sit for weeks at a time but even on back to back days after driving it for 25 miles it still feels the same so I don't see this as flat spots. I don't suspect the balance on the wheel and I can swap front to rear very quickly for a test to rule that out but it was been this way for some time.
What are some other areas to begin looking at??? Steering connections? Ball joints? Tie rod ends? Steering rack? other?
When I equalized them the shimmy went away.
CVT
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
You may also have a tire with internal cord separation. Those speeds you mention are typical for feeling that type of problem.
Age of the tire isn't always a reason for cord separation. It can happen on new tires, cheap tires, and expensive tires.
It wouldn't hurt to have the alignment checked along with the suspension components to make sure everything is tight. The tires can easily be check for an out of round condition or for any bulges in the tread.
Age of the tire isn't always a reason for cord separation. It can happen on new tires, cheap tires, and expensive tires.
It wouldn't hurt to have the alignment checked along with the suspension components to make sure everything is tight. The tires can easily be check for an out of round condition or for any bulges in the tread.
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,035
Likes: 0
From: Atlanta Ga
I've had these Sumitomos for at least 3-4 years or so and very little driving, but I'm certain I had this problem before when I had a set of Firestone Firehawk tires. I really don't think it is any different from when I put these Sumitomos on new.
I think I need to start with some basic things to see what's up, I'll check the pressures, I might benefit from a test of rotation just to see if anything changes and see what I have then.
I think I need to start with some basic things to see what's up, I'll check the pressures, I might benefit from a test of rotation just to see if anything changes and see what I have then.
Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
You need to have your tires balanced and checked for round. Check that the rims are true ect. Contray to popular belief a shimmy in the steering wheel or vibration can only be caused by rotational things tires rims axles ect. Syspension parts cannot cause a shimmy or viberation, Now lets say you have a bad tie rod end and a out of balanced tire the bad tie rod will make the shimmy feel worse. So you need to concentrate on rotational parts
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Safety Car
Joined: Aug 2009
Posts: 3,752
Likes: 276
From: Melbourne, Victoria, Australia
As others have already mentioned the tires can develop problems, bad manufacturing with tread starting to seperate. Flat spots from long periods of hibernation during winter, always increase tire pressure if not using the vehicle for quite some time.
Wheel alignment is another one, if the wheels toe in too far the tires tend to scrub and even skip if it is bad enough.
Check your suspension and do a wheel alignment and get the wheels ballanced again. Maybe get a new set of tires.
Jack the car up and rotate the wheels, look for any woble and look for high spots
on the tread. they should not have any change at all over the tread.
Wheel alignment is another one, if the wheels toe in too far the tires tend to scrub and even skip if it is bad enough.
Check your suspension and do a wheel alignment and get the wheels ballanced again. Maybe get a new set of tires.
Jack the car up and rotate the wheels, look for any woble and look for high spots
on the tread. they should not have any change at all over the tread.
Burning Brakes
Joined: Mar 2007
Posts: 901
Likes: 1
From: Jackson Michigan
I don't know if you are running the same width wheel on all 4 corners or not, but my last tire shop experience had the wheels in the wrong locations. One front wheel was in the back and vice versa.
Instructor
Joined: Nov 2001
Posts: 182
Likes: 4
From: Gardena CA
I can confirm the problems with Sumitomo. I had 2 sets of Sumis and had the same problems with the vibrations at 65-75 mph. After having the tires balanced and alignment check, I finally found out that tires were out-of-round. I replaced them with Goodyears F1. Besides looking good, they solved the problem.
I've had these Sumitomos for at least 3-4 years or so and very little driving, but I'm certain I had this problem before when I had a set of Firestone Firehawk tires. I really don't think it is any different from when I put these Sumitomos on new.
I think I need to start with some basic things to see what's up, I'll check the pressures, I might benefit from a test of rotation just to see if anything changes and see what I have then.
I think I need to start with some basic things to see what's up, I'll check the pressures, I might benefit from a test of rotation just to see if anything changes and see what I have then.
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,035
Likes: 0
From: Atlanta Ga
Well based on this info it sounds like while the Sumitomo is an inexpensive tire, it's not a good choice for a car that is driven sporadically. I was considering a set to go on my C5 Z06 but I think I'll go with something else given that car sees about 2500-3000 miles a year.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
when storing a car or just "resting" a performance car (or any other) its advisable to jack it up and take some of the weight off the tires. If the body is lifted so the suspension is no longer under compression, that's usually enough to prevent flat spots and tires hardness.
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Well based on this info it sounds like while the Sumitomo is an inexpensive tire, it's not a good choice for a car that is driven sporadically. I was considering a set to go on my C5 Z06 but I think I'll go with something else given that car sees about 2500-3000 miles a year.
Now, the Sumitomos are about the least expensive tire out there. They're not a bad option for the money, but yes, there is reason they are the least expensive. For your purpose, however, they're not a bad option.
Now, I understand wanting to keep the miles down, and the car and showroom condition. Unfortunately this to comes at a price. These are cars that are designed to be driven. Now, i'm not suggesting to go out and drive the snot out if it. I might suggest, however, to move them perhaps a bit more frequently, or to take them out for a bit of a longer run. Ten miles is not going to do a whole lot to losen up bushings, lubricate joints and the like. Leesvet also has a great suggestion in terms of relieving some of the pressure of standing still when in storage.
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,035
Likes: 0
From: Atlanta Ga
Well I rotated the tires front to back and went on a test drive and it did feel better, not perfect but better than before. I was about to cruise up to about 63mph on the street in the area but I need a trip on the highway for a verdict. They needed to be rotated anyway so nothing lost by doing that.
Most everything else seems in order so I'm going to drive it a few times over the next week or two like my 11 mile trip to work each way to see how it feels. Then I might look at a re-balance to see if we can get it better.
Yes, I agree I need to be better about running the car more, but something always gets some time on the top of the 4 post and often times it is the C4, right now it is the race car but for a week or so the C4 will be accessible. I know I can't complain but the storage makes things a bit more complicated.
Most everything else seems in order so I'm going to drive it a few times over the next week or two like my 11 mile trip to work each way to see how it feels. Then I might look at a re-balance to see if we can get it better.
Yes, I agree I need to be better about running the car more, but something always gets some time on the top of the 4 post and often times it is the C4, right now it is the race car but for a week or so the C4 will be accessible. I know I can't complain but the storage makes things a bit more complicated.
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,035
Likes: 0
From: Atlanta Ga
Well, driving the interstate today the shaking is lessened but not really where I want it so we might need to see about a re-balance but I'm just not in for new tires right now, these things look brand new.
During the swap the other night I did use a little burnout to type to adjust the rears a bit! :-)
During the swap the other night I did use a little burnout to type to adjust the rears a bit! :-)
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Dolfan has asked about front tie rod ends and such.
So can we assume the vibration is felt in the steering wheel?
Or are all four corners giving you issues?
FWIW
Not properly torquing the front lug nuts can cause for the rotors to warp.
Stiff or failing half shaft u-joints can shake the rear end.
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,035
Likes: 0
From: Atlanta Ga
I'm going to get a friend who is an Audi tech to give it a drive and look. Sometimes you need another set of eyes on the problem.
The shake is definitely through the steering wheel though. The other quick test is to pul the front wheels of my C5 Z06 just for a trial, they are 265/40/17 but maybe a slightly wider wheel, but that would rule out the wheel and tire.
The shake is definitely through the steering wheel though. The other quick test is to pul the front wheels of my C5 Z06 just for a trial, they are 265/40/17 but maybe a slightly wider wheel, but that would rule out the wheel and tire.