Tire rotation makes ride worse

[DavidPeab]

While trying yet another test to fix my Relentless steering wheel shimmy - Part II I had my tires rotated front to back today. My steering wheel shimmy got much worse (nearly constant instead of 20% of the time). The tires are fairly new and have been rotated once by me at about 3k miles and again today at about another 3k.

My question is: Is there a "break in" period for tires after they are rotated? Does the tread have to adjust to its new road position? Or should I just have them rotated back to the position which gave me the least shimmy? NOTE: This only concerns the tire rotation issue. The shimmy issue is covered extensively (nearly obsessively) in the link above.

David

[cerbomark]

no , they should be fine right away... make sure they are balanced correctly too.

[DavidPeab]

I'll swap them back tomorrow. I imagine at least one of the back rims is worse than the front. They were balanced about a month ago and I had the alignment checked at the same time. I watched the guys rotate them and I didn't see any lead hit the floor. When I got home I re-torqued them to 75 lbs and inflated the front to 32 psi and the back to 31 psi. The specs call for 30 and 29 but I add a bit more in the winter because of the cold.

[lavarock]

When steel belt radial tires first came out my father who did front end alignments had problems with radials if they were cross rotated. It seamed the steel belts would take a set and did not like to rotate in the reverse direction. He fixed many shimmy problems by just replacing the tires. Were the tires balanced? Another cause of shimmy.
I know it is expensive but new quality tires may fix the problem. May try to find someone with a Subaru that will let you exchange tires to a test first.

[DavidPeab]

May try to find someone with a Subaru that will let you exchange tires to a test first.

I live in Pasadena, MD near Baltimore and Washington DC. Anyone?

Balanced, road force balanced and mid to upper range tires. Not Michelin but not Wal Mart either. Mr. Tire house brand.

[DavidPeab]

So, I had them re-balanced today and none were off by more than .25 oz. They are all at 0.00 now. Rotating them back to front again restored my shimmy to its usual intermittent annoyance and not the full-out arm vibrating state it was in at the beginning of this thread.

[subiesailor]

Originally Posted by DavidPeab

So, I had them re-balanced today and none were off by more than .25 oz. They are all at 0.00 now. Rotating them back to front again restored my shimmy to its usual intermittent annoyance and not the full-out arm vibrating state it was in at the beginning of this thread.

I had one tire going egg shape around 25K it was too far gone to put on the front end. Replaced all of them with BFG touring tires about a month ago the originals were bald at 40,000 miles

The continentals are just terrible tires suffer with them till they are done and get a better tire!!!

[subaruman49]

Sorry to hear about your " shimmy" ugh...... I have ben driving for over 35 years and have NEVER rotated my tires. I always get at least 60,000 on them and they wear even. No bald spots, cupping, uneven wear.
Tire pressure should be checked once a week. It could be that one of the tires is " out of round" or has a " blob" area throwing off the balance. I used to work for a tire shop and saw all kinds of things. Check your rims as well. Good luck

[cardoc]

So is the shimmy still at the same wheel or is it moving with the wheel?

Did you buy tires that are "directional", meaning they are designed to rotate in only one specific direction in forward motion? The reason I ask: If one of the tires is mounted "backward" on the rim, it could cause a shimmy/shake at speed since the tread pattern is running opposite from its design. Look at the tire and see if there is an arrow indicating its rotation direction or an imprint stating "this side out". You could have, and don't laugh its happened, a tire on the wrong side of the car or mounted backward on the rim. If its mounted backward, switching sides won't cure it. It will need to be dismounted and remounted correctly. And if this ends up being the issue or part of the issue, you could refer to the guys at Mr Tire as Mr Learn How to Mount a Tire Properly.

[DavidPeab]

So is the shimmy still at the same wheel or is it moving with the wheel?

Not sure which of the two rear ones caused the worse shimmy. The tires and rims look true. I asked Mrs. Santa for a floor jack for Christmas (after 23 years we are cool with less romantic presents). Assuming it comes through, I will swap the wheels around in patterns that will allow me to determine the worst result. Running the dial-gauge on them is what prompted me to swap front to rear the first time. So I think it is more than the rims. The process of elimination will narrow it down.

Did you buy tires that are "directional", meaning they are designed to rotate in only one specific direction in forward motion?

They are Runway Enduro 816, 225 60 R16, 98H rated A for M+S and traction. I did not see any arrows or this side out indicators, so non-directional. I was reminded by the mark on one of them that I took them to Goodyear to have them road force balanced by their resident guru after I lost any confidence in Mr. Tire. Goodyear would have remounted them the correct way anyway. The guru thought one of them could be bad, but when I went back to Mr. Tire they "assured me" that it was rare and this batch were just fine. So, even if they are crap, Mr. Tire is not going to help.