Hello All,

Last week I replaced the front tires on my 2005 STR. The tires that were on there previously were Continental 245/40R18 ZR rated. They had plenty of tread left but because the front end got out of line around 10,000 miles ago (I had the front end re-aligned about 6,000 miles ago), they started to wear on the inside, causing horrible road noise.

I replaced my tires with Dunlop 245/40R18 ZR rated-All season tires. As soon as I left the tire shop, I notice my steering wheel had a slight shake in it that wasn't there before. I was on my way to an appointment and so I couldn't turn around and go back so today I went back and had the shop re-balance my tires but my steering wheel still has the shakes.

The door jam recommends the tire pressure to be set at 40psi front and back. The shop had the new fronts at 35psi and I changed it to 40psi as recommended.

Does anyone have any suggestions about tire pressure or could the old tires have been hiding a problem that was brought out by the new ones?

 

Honestly, tire pressure for the most part is preference (within range 32ish-42ish). People for the most part set the fronts and backs differently. I do a 37/41 on mine, but it also depends on the season.

Anyways seeing as your pressure is matched, it wont matter if they are at 37 or 40, you will still have the shimmy. If you brought your car in with no shimmy, now have a shimmy it clearly has to do with balancing. The only other thing since you have already had an alignment would be that you have unmatching fronts and rears, but I doubt it.

In some instances with my STR and Porsche, I have had to bring it back upwards of 3-4 times before they got it right. Also make sure you are getting it done on a Hunter road force machine, if they dont have one there, take it elsewhere.

Hope this helps, and balancing CAN and usually is a PITA!!!!

 

I agree 99% its wheel balance.

How bad is the shake? Is it through the entire speed range, or does it tend to find a "resonant" speed where it's most pronounced, and then go away after that.

I had major issues with my 19" wheels, and steering shake, which got worse when Dunlop SP Sport 01's went on.

George

 

Thanks for the input Bull. I'm thinking about going ahead and getting the car re-aligned again. From what I've been told, just the wrong pot hole or rough railroad track can mess things up.

The tire shop spent about 45 minutes trying to perfect the balance but if they don’t have the right equipment, it won’t do any good.

 

The shake starts around 45 mph and is consistent through 75 mph. The road surface has a lot to do with it. On Concrete type roads here in NC, it doesn't show up at all, but on newer Asphalt, it's very pronounced.

 

Find the closest shop to you with a Hunter GSP9700 road force balancer:

http://www.gsp9700.com/pub/search/findgsp9700.cfm

Go get the two fronts road forced balanced. If the tires wont come into round, go straight to the tire shop and have them replaced.

A shake in the steering wheel is the front tire, a shake or vibration in the seat is the rear ones.

George

 

110% agreed. I remember after many a balancing issues going on that website, using their search engine and finding a place with the newest Hunter balancer.

Also remember, if you are not satisfied, bring it back. 10 times if you have to until its right. Most tire shops have some kind of policy that allows you to bring it back and have it re-done within a certain amount of days. I would imagine with the staggered wheels, low profile tires, and stiff suspension that the STR is more challenging to get everything flowing smoothly and makes for easy detection if a balancing or alignment is even slightly off (SHIMMY).

 

Thanks George for the great website. I went on it and found 45 shops near my house. Unfortunately, the shop where I got the tires wasn't on it. The local Nissan place 5 miles from my house has one and I called and they said it would be $45 for the front tires. I hate to spend anymore $ after just getting new tires, but the shake is going to drive me crazy if I don't get it fixed.

 

I have a similar problem with the front RHS standard wheel on my STR.
When the old original tyres came off, the new Dunlops highlighted the problem of the alloy wheel being out of balance.
And I mean really out of balance, nothing that weights could fix.
The wheel has to be sent out to be repaired. I could see the wheel being 'out' as it was rotating on the balancing machine.

And as for the modern style low profile tyres, I would definately not go under 42psi unless you want to cook them which would lead to extreme premature wear.

On my Citroen C5 I only got 15,000 miles on a brand new set of Hankook tyres that I ran at around 32psi. They were the top of the range.

 

From my understanding the tires designated "all season" are made from different compounds, that is why you can drive them in below freezing temperatures, wheraes the performance summer tires you cannot. Or its not recommended. The "all seasons" also have a higher wear milaege than the summers, around 30-40k. That being said, i would assume running around 40 or slightly below on an all season tire would be just fine. Maybe Im wrong.

 

Bull, were you able to get the wheels balanced after having them "road forced balanced"? Did it get fixed the 1st time?

 

Yes they eventually balanced out. Unfortunately, even with the road force balancing I had to bring it back a second time. I would just have them do the roadforce, tell them your going to go test drive it, find the nearest highway and get it up to 85ish and see if its ok. I have always found that any shimmy I've had always tends to be at my highway cruising speed of 70-75. Quite convienient.

 

I'm not a "tyre man" so I'm not a specialist, but try swapping front and rear wheels. Also, have they fitted balance weights to the INSIDE of the wheel? Are you sure the pothole damage has not "twisted" a wheel ever so slightly? You can test this your self by jacking up the wheel under the spring pan so its clear of the ground. Using something like a laborotary stand, have its clamp arm just clear of the rim then spin the wheel. Any eccentricity/twist will show at once. Just my four penn'orth.
Leedsman.

 

What would swapping front and rear achieve? (It can't be done on an STR, of course.)

 

It would allow for you to isolate the issue to a wheel or the hub/brakes. I've done it many times in trying to diagnose a vibration. I didn't post that suggestion because of the second part of your post..That wouldn't help the OP since they have an R that has staggered wheels.

 

On my STR I have 245/40/18's on the front and 275/35/18's on the back so I can't move them front to back. Also, the car was perfectly smooth (even at 100 mph+ it felt like 30 mph) before I got the new front tires.

I called all the local shops with the "road forced balance" machines and the cheapest quoted $49 for all four tires, so it looks like I'm going to have it done asap and see if that fixes it.

 

That seems very reasonable, and like I said let them know you are going on a test drive and will be right back if there is any shimmy. Get her up to highspeed and cross your fingers! Good luck man

 

I also recommend "Road Force" balancing. I did find the car dealers are not very good at it. And when I brought it back because it was not right they would not recheck them!!! Try to find a high performance shop or tire dealer. Yes I know you already paid for a balance but the STR is a bit different with the staggered rims.
I am NOT a fan of Dunlop tires but maybe that's just me? I have had good luck with the so called inexpensive high performance tires. Brands such as Nexen, Khumo, Nitto. Usually made in Korea. Seems like with cars the Korean products have also really improved. I am very impressed with the Hyundai Genesis!!
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Just another 2 cents...... I personally have never had Dunlaps, but the cuz with the 3 did. He used to complain that even in the summer it took forever for his tires to heat up and smooth out.... So, after the balance be sure to heat the tires up and see if it gets better..

 

I have had a set of Dunlop Radial Rover A/T tires on my 1999 Ram pickup since November 2002. They're just now pushing 30,000 miles and have been good tires, especially given the big 5.9-litre V8 in my truck. It can really chew up some rear tires if you're not careful. These Dunlops still hold their air today just as long as they did when they were new....

All through the 1990s I ran multiple sets of Dunlop D60 A2 tires on our 1989 Acura Legend L 5-speed manual sedan. They were always great tires, very reasonably priced, and I never had a problem with any of them. They delivered right at 40,000 miles per set which was just about what they were warrantied for (45,000-mile treadwear warranty if I remember correctly)....

On my wife's 1996 Jeep Grand Cherokee AWD, I ran multiple sets of Dunlop SP40 tires. Again, great tires that were very reasonably priced and never had a problem with them. Even with AWD and the 5.2-litre V8 in that Jeep, those tires would do 45,000 miles per set....

So unlike some others here, I've had good success with Dunlop over the decades. That's one reason why the Dunlop SP Sport Signature tops my list for our S-Type replacement tires when that time rolls around....