Front tires bald after 4000 miles

[rollandburn]

Hi, I’m just on my way back from a trip out east (4500 kms total) and am noticing the car is tracking over highway grooves, dodging left and right. Before leaving on the trip the car had 2000kms on the following work...

: last fall I put in all new polybronze ER bushings, sport bilsteins w/ raised spindles, turbo tie rods, tarrett sway bars, rebuilt steering rack, new bridgestones summer rubber on 16 x 6/7’s. Brought the car to a ‘reputable’ 911 shop who buttoned everything up and had the alignment done. Everything seemed great, felt tight buzzing around the city.... felt ready to head out to the coast on a long trip.

During the final legs of the return trip I was pretty sure something was amiss with the front on account of the steering feel so I inspected the tires and am unhappy to report the inside of both front tires are burnt right off... no tread. Looks almost new on the outside of each tire. It’s almost like she was snow plowing all the way down the highway. With the naked eye it sure looks like there is camber on both front wheels with the top of the wheels noticeably inboard from the bottom. Rear tires are fine.

I’m curious, do all of the suspension mods mentioned above also come with alignment compromises where one should expect to wear through fronts this fast? I thought with the raised spindles alignment should not require compromise at euro height. Add to that the lack of any significant camber required for 6” Fuchs (as far as I’m aware).

On the bright side I just got new 16x 8” and 9” Fuchs and will need new rubber anyway... but I suppose I am, again, second guessing even bothering to take my car back to this ‘reputable’ 911 specialist. Just not sure if this is normal, or something the shop just didn’t get right (ie. with alignment).

If it isn’t normal, what’s the best approach if I do take it back to the shop? Any advice appreciated.

Ps. I just looked at the invoice and there is no alignment listed... however it had to have been done, they knew all suspension was new.

Pps. Tire pressures were/are 2.5 bar in the rear, 2.0 in the front.

[jpnovak]

NO, suspension mods do not specifically induce tire wear. What are your alignment settings?

Typically camber doesn't wear out tires like you describe. Incorrect toe settings will. You are right, its a snow plow effect.

If you don't see it on the invoice along with numbers then it wasn't done.

[freeform911]

Camber and toe #'s.
Maybe a toe issue?
Isn't darting an effect of to much toe out?

[rollandburn]

Some pics... probably hard to see the wheel angle.

I don’t have alignment numbers unfortunately, no paperwork. Invoice shows all other work though. Grrrr.

Anyone know of a REALLY reputable shop in Toronto?


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[emcon5]

My guess, toe.

[old man neri]

Sometimes all it takes is one pothole to throw the alignment way off. It may have nothing to do with your suspension work.

[86 911 Targa]

^^^^
Off topic, but what is this?

Gerry

[rollandburn]

Originally Posted by 86 911 Targa

^^^^

Off topic, but what is this?



Gerry

Por-15


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[rollandburn]

Originally Posted by old man neri

Sometimes all it takes is one pothole to throw the alignment way off. It may have nothing to do with your suspension work.

I was thinking the same... the roads between Toronto and Halifax aren’t exactly baby bottoms and the Cabot Trail is absolutely brutal in places. Maybe a good jarring knocked it out of alignment. What made me dismiss this possibility, or not give it much weight, is the fact both front tires are equally burnt on the insides... I’m envisioning a pothole on one side though. Do you think the toe could get knocked outwards equally with a good smack over a raised bump perpendicular to the direction of travel? Not like a speed bump at 120... but the same idea. (Point I’m making is I didn’t hit one side hard, but many times both wheels would hit raised areas going across the Road with an uncomfortable thump at speed).


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[porsche930dude]

you can do a quick check of toe simply with a tape measure just measure to that center tread line on the tire in the front and back as high off the ground as you can get. It will give you a pretty accurate idea of whats going on. Alignment machines can be real finicky and often put out false readings.

[rollandburn]

Originally Posted by porsche930dude

you can do a quick check of toe simply with a tape measure just measure to that center tread line on the tire in the front and back as high off the ground as you can get. It will give you a pretty accurate idea of whats going on. Alignment machines can be real finicky and often put out false readings.

I think I know what you mean... the widths between fl/fr tires and rl/rr tires should be the same. If a measurable difference is found that would mean a toe in/our issue. Not sure why but I just assumed the rear was wider and didn’t consider that measurement... thanks.

[darrin]

a bit off topic, but aren't you going to run into a similar issue when you try putting 16x8 wheels up front -- seems the general advice to minimize rubbing the fender rim when running wider front wheels is to increase camber (bring the top of the tire closer to center), which will put more weight on the inside edge of the front tires . . . .

[old man neri]

Originally Posted by rollandburn

I was thinking the same... the roads between Toronto and Halifax aren’t exactly baby bottoms and the Cabot Trail is absolutely brutal in places. Maybe a good jarring knocked it out of alignment. What made me dismiss this possibility, or not give it much weight, is the fact both front tires are equally burnt on the insides... I’m envisioning a pothole on one side though. Do you think the toe could get knocked outwards equally with a good smack over a raised bump perpendicular to the direction of travel? Not like a speed bump at 120... but the same idea. (Point I’m making is I didn’t hit one side hard, but many times both wheels would hit raised areas going across the Road with an uncomfortable thump at speed).


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Doesn't matter which toe is out and by how much. Doesn't have to be equal. You will center the toes with the steering wheel to go in a straight line. Does that make sense?

Ah yes, NS roads. I know all about them. Maybe a good bump settle something in your suspension that just hadn't seated quite right.

Anyways, my advice would be to go to an alignment shop and see what the toe is. I'm not a suspension expert though.

I hope you enjoyed the Cabot Trail.

[Trackrash]

Originally Posted by porsche930dude

you can do a quick check of toe simply with a tape measure just measure to that center tread line on the tire in the front and back as high off the ground as you can get. It will give you a pretty accurate idea of whats going on. Alignment machines can be real finicky and often put out false readings.

+1 Tape measures don't lie.

Then grab each wheel at the top and see if they can be moved, any play. Then grab the front and rear of the tire, wiggle back and forth. Should be no play.

Then jack up the car and repeat. Lots of things can come loose, so do a through check.

[DRACO A5OG]

+1 Tape Measure it.

Get a wheel chock, use duct tape, place it about 4" from the ground, tape hook upside down and place in a tread groove that is deep enough then measure the opposing tread groove. Do front and back, you will see.

Definitely too much toe in, man those tyres are not cheap either :-(

[RDM]

Originally Posted by rollandburn

I think I know what you mean... the widths between fl/fr tires and rl/rr tires should be the same. If a measurable difference is found that would mean a toe in/our issue. Not sure why but I just assumed the rear was wider and didn’t consider that measurement... thanks.

I think what he means (and what I would mean) when checking front toe would be to measure front of front left tire to front of front right tire, then back of front left tire to back of the front right tire. The difference of those two measurements would be your front toe.

This measurement is not affected by different wheel widths front/back. You can repeat this measurement for the rear wheels to find rear toe, but that doesn't sound like where the problem is.

[da Vinci Dan]

How far are you from the shop that did the work? I would get them to look at it and the tires.

[LJ851]

Originally Posted by DRACO A5OG

Definitely too much toe in, man those tyres are not cheap either :-(

Too much toe out is the problem here.

If it were too much toe in it would wear the outside edge of the tires and would track reasonably well.

[rollandburn]

Originally Posted by darrin

a bit off topic, but aren't you going to run into a similar issue when you try putting 16x8 wheels up front -- seems the general advice to minimize rubbing the fender rim when running wider front wheels is to increase camber (bring the top of the tire closer to center), which will put more weight on the inside edge of the front tires . . . .

If I understand correctly 951 16x8 Fuchs fit well under Carrera fenders with a roll of the lip, and around -1 camber (something you want). It sounds like the current issue has to do with toe misalignment which is much harder on tires (something you don’t want). Wear from neg camber would be less, expected, and intentional, whereas the current toe wear is unexpected, definitely due to a problem, and happening ridiculously fast. That’s how I’m looking at it, but suppose you could see them as similar issues.

[rollandburn]

Thanks for all the feed back. After arriving home last night I noticed the drivers side front skirt was nearly touching the ground where I was parked to unload. That side was much lower than the passenger side, could barely get my hand on top of the tire between the wheel well. I used two hands in the arch of the wheel well and pulled up gently... the car rose. Push down on the fender, it dropped back to the low position. Tried the same on the passenger side, didn’t budge. Today I’ll go for a drive back to the shop and see what he says.