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Instability on the Freeway by RilesOfSmiles
Started on: 07-13-2013 06:26 PM
Replies: 7 (223 views)
Last post by: fierosound on 07-14-2013 10:19 AM
RilesOfSmiles
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From: Issaquah, Washington
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Report this Post07-13-2013 06:26 PM Click Here to See the Profile for RilesOfSmilesClick Here to Email RilesOfSmilesSend a Private Message to RilesOfSmilesEdit/Delete MessageReply w/QuoteDirect Link to This Post
When I drive on the freeway at 65+ mph I'm all over the road in the middle lanes. My suspension is in good shape and my alignment is great so I know it's not that. In fact on a smooth road it's quite easy to control at 100+ mph. It's just these stupid grooves in the road on the freeway I'm pretty sure are throwing me around. I think they are from wear. Anyone else have this issue? Is there something I can do to make it more stable in these lanes? Changing lanes is extremely frightening as it will lurch in and out of the grooves.
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Fierobsessed
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Report this Post07-13-2013 06:34 PM Click Here to See the Profile for FierobsessedClick Here to Email FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sounds like the toe in the rear is out, or you have a worn component, possibly wheel bearings or bushings or loose bolts. Try checking for play in the wheel with the car jacked up. But it will most likely be an issue with rear toe.
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BlackEmrald
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Report this Post07-13-2013 08:43 PM Click Here to See the Profile for BlackEmraldClick Here to Email BlackEmraldSend a Private Message to BlackEmraldEdit/Delete MessageReply w/QuoteDirect Link to This Post
X2 for rear suspension problems. Check your tie rods.
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BV MotorSports
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Report this Post07-13-2013 10:07 PM Click Here to See the Profile for BV MotorSportsClick Here to Email BV MotorSportsSend a Private Message to BV MotorSportsEdit/Delete MessageReply w/QuoteDirect Link to This Post
First time I drove to Florida the back of my 87GT started wagging. Scared the hell out of me. Turns out I had too much toe in the rear and the grooves in the road only compounded the problem. I'd also suggest you do a nut and bolt check including the cradle bolts. Also, tire width can be an issue. My 2005 Evo was fine with the stock tires but when I put on my wide rubber, it would bounce from groove edge to groove edge on some roads.

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RilesOfSmiles
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Report this Post07-13-2013 10:15 PM Click Here to See the Profile for RilesOfSmilesClick Here to Email RilesOfSmilesSend a Private Message to RilesOfSmilesEdit/Delete MessageReply w/QuoteDirect Link to This Post
The tires are wider than stock but I just noticed it sitting on the flatbed the rears look like they have more camber than the fronts. I always just assumed it was because the grooves were farther apart than the tires. The best way I can describe it is like trying to stay in the middle of the wake when a boat is towing you. When the boat turns and you slip outside the wake all hell breaks loose
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lateFormula
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Report this Post07-14-2013 12:10 AM Click Here to See the Profile for lateFormulaSend a Private Message to lateFormulaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Check the toe and the thrust angle.
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DIY_Stu
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Report this Post07-14-2013 01:35 AM Click Here to See the Profile for DIY_StuClick Here to visit DIY_Stu's HomePageSend a Private Message to DIY_StuEdit/Delete MessageReply w/QuoteDirect Link to This Post
Have the rear checked again.
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fierosound
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Report this Post07-14-2013 10:19 AM Click Here to See the Profile for fierosoundClick Here to visit fierosound's HomePageClick Here to Email fierosoundSend a Private Message to fierosoundEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by DIY_Stu:

Have the rear checked again.


Yup. Rear toe should be 0 - Zero degrees
http://home.comcast.net/~fi...e/FieroAlignment.pdf

I had an alignment done on my 87 GT a couple of weeks ago. NEW alignment machines still have the WRONG specs for rear toe.
They have never corrected them to the specs in the Technical Service Bulletin - TSB 87-3-10 dated March/1987

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[This message has been edited by fierosound (edited 07-14-2013).]

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