2007 ZX5 Focus
Stock Springs
ZX3B Shocks and stuts

Hey guys,

Just wondering if anybody has ran across this. I just replaced the stock tires with a touch bigger tire, 205/55R-16 Firestone Firehawk Wide Oval AS, since Michigan roads are terrible and destroy lower profile tires. Anyways after installing the tires I had a swaying back and forth when I'm on the highway going 70+ mph and hitting certain stretches of pavement. Imagine the rear of the vehicle is like a dogs tail going back and forth. Thats what it feels like sometimes when you hit uneven pavement.

I took the vehicle to my uncle at Midas and he put the car on the computer alignment machine. The rear was out of spec. The tow was to much in and the camber was off. He ended up using the camber bolts to fix the rear and get the tires almost strait up in the back. I believe he also has almost no tow in in the back. Before that he also installed a new set of ford racing shocks and struts in case it was a issue with those.

After all that the rear still sways, but it does it less often. I drove the car 13 hours down south and every once in awhile it happens, however on Michigan roads it does it alot. Any body have any answers? Maybe the stock swaybar is to stiff I dont know. [dunno] Only thing I can think of is the pattern on the tires is screwy causing it!

Check the wheel bearings my old foci used to do that but on wet roads only, when I change one wheel bearing the car stop doing that

Thanks Ill jack the car up and see if there still in good shape!

http://www.focusfanatics.com/forum/showthread.php?t=80566

Found the above thread seems I'm not the only one, its called bump steer. My 2002 ZX3 never had this and drives great and was lowered too. I believe I still have my old eibach rear shocks from my 2002. Those should be stiffer then the zxb shocks I just put in the car. Possibly that and a stiffer rear bar will fix this...

Any wide and/or stickier tire will tend to follow the grooves in the road. That may be your issue.

Play with tire pressures a little as well. Sometimes as little as a one or two pound adjustment can have a impact on handling (and ride quality). What PSI are you currently using? Some tires have softer sidewalls and tend to sway a little more than others. Tire pressure can reduce this to an extent.

What Geezer posted! oh yeah

2007 ZX5 Focus
Stock Springs
ZX3B Shocks and stuts

Hey guys,

Just wondering if anybody has ran across this. I just replaced the stock tires with a touch bigger tire, 205/55R-16 Firestone Firehawk Wide Oval AS, since Michigan roads are terrible and destroy lower profile tires. Anyways after installing the tires I had a swaying back and forth when I'm on the highway going 70+ mph and hitting certain stretches of pavement. Imagine the rear of the vehicle is like a dogs tail going back and forth. Thats what it feels like sometimes when you hit uneven pavement.

I took the vehicle to my uncle at Midas and he put the car on the computer alignment machine. The rear was out of spec. The tow was to much in and the camber was off. He ended up using the camber bolts to fix the rear and get the tires almost strait up in the back. I believe he also has almost no tow in in the back. Before that he also installed a new set of ford racing shocks and struts in case it was a issue with those.

After all that the rear still sways, but it does it less often. I drove the car 13 hours down south and every once in awhile it happens, however on Michigan roads it does it alot. Any body have any answers? Maybe the stock swaybar is to stiff I dont know. [dunno] Only thing I can think of is the pattern on the tires is screwy causing it!


I found your problem

Edit:
I have had about 4 or 5 cars (late model BMW's) come through my shop with these tires and they all handled the same, like junk

The oem kumho's would follow road crown and abnormalities in the road cruising on the highway from time to time. Going to a H rated 205 Michelin tire made my car ride more luxurious than ever before. You get what you pay for and no one should pay for Firestones

I found your problem

Edit:
I have had about 4 or 5 cars (late model BMW's) come through my shop with these tires and they all handled the same, like junk

The oem kumho's would follow road crown and abnormalities in the road cruising on the highway from time to time. Going to a H rated 205 Michelin tire made my car ride more luxurious than ever before. You get what you pay for and no one should pay for Firestones

I had this exact same issue while on a road trip.. on a completely bone stock 2006 focus st, completely stock including the original tires.

I was in the middle of somewhere i wasn't familiar with and used my gps to find an auto shop...i was worried it was something major....

closest shop was a shop that was a firestone dealer, and it was the only shop for over 20miles (I went against my personal beliefs and went there) and all they did was put on new tires and that was it, Firestone Champion HR http://www.bestusedtires.com/images/additionalimages/26044_2.JPG

not only did it cure my problem but my car had a better overall feel to the handling. only drawback is more road noise than I am used to

I had exactly this same issue when I had a blown rear damper.

You might want to check the rear shocks. It may be coincidence that this happened when you changed tires.

[:)][:)][:)][:)][:)][:)]*edit[:)][:)][:)][:)][:)][:)]*

Never mind. Missed that you already changed the shocks. :banghead: