Car ate two front tires in 5000 miles
#1
Car ate two front tires in 5000 miles
2006 GT convertible with 34k original. In March at 28k I installed four new Michelins at the local tire shop. The original tires, although worn, showed no unusual wear One tie rod end was replaced and an alignment was performed--$1000. Last month at 30k my mechanic told me that in order to pass state inspection (Maine) both lower balljoints needed replacement. He showed me the play which didn't look like much to me but I ok'd the work so the car would pass inspection. Another $540 spent. Last week we were on a driving vacation in the Gaspe peninsula in Quebec when the left front went flat. The entire inside of the tread was worn right down to the steel cord, and the right front looked exactlly the same. I called around and had 4 new Coopers installed although an alignment couldn't be done. $700. We limped home, and on the way I noticed the front tires were already beginning to wear on the inside. Upon arrival home, the next day I had another alignment performed by the shop that sold me the Michelins, expecting it to be way out of line--which it wasn't! About half a degree of toe-out on both sides, a very small amount and not enough to cause the accelerated wear. The Coopers were rotated before the alignment so I could "start fresh". I wasn't charged for this alignment. At any rate, I am totally bamboozled as to what has been going on here. The car had 18k on it when I bought it about a year ago and has never been in an accident. The original tires, replaced at 28k, showed no signs of unusual wear. So at this point, I'm in a "let's watch and see what happens" mode. Anyone have any ideas?
#2
You should have the pre/post alignment printout from the shop(s). Post one and lets have a look. At this point it sounds like the alignment is off or something is loose up front. Perhaps something was botched with the ball joint/control arm replacement. It's all just a guess at the moment.
Off the top of my a half degree of toe out (0.5) is way too much and would scrub the inner tires as described. Spec is 0.10 +/- 0.20 so -0.10 to 0.30. with 0 to negative -0.10 (toe-in) preferred for stability or you get that inner tire wear. That's probably your problem right there. And yes, toe-out and excessive toe-out can cause excessive/rapid wear. These cars already have a preference for heavy negative camber, couple that with excessive toe out and you're ruin a set of tires pretty quick.
Again, post up the printout to have a look or better yet, take to a local ford dealer and have the alignment checked and updated.
Off the top of my a half degree of toe out (0.5) is way too much and would scrub the inner tires as described. Spec is 0.10 +/- 0.20 so -0.10 to 0.30. with 0 to negative -0.10 (toe-in) preferred for stability or you get that inner tire wear. That's probably your problem right there. And yes, toe-out and excessive toe-out can cause excessive/rapid wear. These cars already have a preference for heavy negative camber, couple that with excessive toe out and you're ruin a set of tires pretty quick.
Again, post up the printout to have a look or better yet, take to a local ford dealer and have the alignment checked and updated.
#3
OK, I've attached the two alignment sheets. The first one is when the tires were installed in March of this year when the car had 28k on it. The second was performed after the tires were shredded and the Coopers had been installed at 33k, already showing wear after only 800 miles. The lower ball joint replacement was done at around 30k miles in June of this year, before the second alignment.
#4
#5
OP - Looks like when the ball joints were replaced a new alignment wasn't performed so the excess negative toe caused the accelerated wear. Too much negative toe has a greater influence on bad tire wear than too much positive toes because of a few factors, when you accelerate, the front of the tire tends to push outward towards negative toe. These cars are very biased with negative camber and as you increase your negative camber you can get some negative toe (toe out). so that will further negate some excess positive toe.
One thing I find very unusual in your printouts are your camber specs on the right front between your first alignment (after) and your second alignment before and after. Camber is not adjustable on these cars in stock form. You can expect a variation of +/- 0.1 degrees on the camber (like the left side) from measurement-to-measurement error but, not go from -0.1 to -0.7 then back to -0.4 without having caster/camber plates or camber bolts to account for that change, I suspect you have a suspension issue on that side.
They only replaced the ball joints? Your control arm bushing are most likely shot on the passenger side causing that variation and contributing to the tire wear. It's not typical to replace just the ball joints on these cars as it's easier (and typically cheaper) to replace the arm with ball joints since the bushings also need replacing.
Last edited by Derf00; 07-24-2019 at 01:47 PM.
#6
Definitely. I just had the ball joints and bushings replaced on my front control arms earlier this week. The steering has become very responsive and almost go kart like. I love it. The replacement parts were Energy Suspension red bushings & Moog ball joints. A new wheel alignment will be necessary.
#7
Is there a way to tell if the control arm bushing are bad? At this stage we're just watching the front tires for wear, but I I'm not crazy about messing up a second set of front tires--actually, a third because the second set was rotated before the second alignment. Thanks, by the way, for all your input.
#8
Is there a way to tell if the control arm bushing are bad? At this stage we're just watching the front tires for wear, but I I'm not crazy about messing up a second set of front tires--actually, a third because the second set was rotated before the second alignment. Thanks, by the way, for all your input.
You can also jack the car up on that side and get a pry bar in there nearest to that bushing and the sub frame and push against the control arm using the subframe as your fulcrum. There should be no movement/give from the control arm.
Changing the arms out isn't super difficult, there are a couple of tricks to make it easier that I can share if you decide to or need to replace them.
#9
Replacing the front control arms is actually pretty straightforward and can be accomplished in less than two hours. Since the toe alignment may be changed with new control arms (or refurbished original control arms with new bushings/ball joints), it's wise to have it checked and adjusted if necessary.
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BigDinTexas
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