I know we have talked about this before, and no this isn't about what size, type or brand. This is about the front and rear wear effects and what we need to do about it.
I have 19k miles on my truck, I have already said my rear tires are wearing in the middle and over the weekend I checked the front and they are wearing on the inside. Almost to the point of no tread left. I am calling my service rep today but I think this really needs to be addressed by GM.
How many Miles should we get from these tires?
I was talking to my husband about it last night and his first response was over inflation on the rears, I said no 30lbs. He thinks the dealer will just say I should have gotten the front end alignment. Sure but there has been no noticable pulling.
So anyone buying new or have few miles should do what ?
Get an alignment, wait til the tires wear unevenly and at a very low mileage?
Should the front and rears have the same amount of pressure?
The tires were designed to run 30 psi on this vehicle. The rears sound like over inflation. The front sound like alignment. Have you lowered the vehicle? If you have, then correct alignment is essential.
Hey wildcat I carried mine in for service about the tires and the service rep. said I needed to have an alignment at 15,000 miles. My front tires are worn on the inside also with 22,000 miles. I let the shop do the alingment front and back and asked for a print out of the work. The service rep. said I was going to have to talk to the District service rep. about the tire wear. Because the alingment was not off that bad.
I have 18,400 mi on mine and they are wearing just like Wildcat's. I check tire pressure every week and keep 30psi (cold) in all four tires. I think there is a problem somewhere!! Widcat, keep us informed as to what you find out. Thanks.
No mine has not been lowered and I have kept 30PSI in mine from the beginning!
If there are so many that are having this problem then it needs to addressed when you buy your truck. Don't wait until it is to late!!!! And in the case of the alignment not being off that much why such bad wear! This just doesn't seem right to me!
Buffy, did you get your SSR aligned after replacing your front tires?
I'm not too surprised by the wear on the inside of the front tires. This will be more prevalent on SSRs that are driven easy or mostly on the interstate.
Reason is the front alignment calls for about 1 degree negative camber which will cause that type of wear.. The only thing that masks it is to wear the outside edge of the tire by pushing it around the corners...
My SSR: 06 Pacific Blue 23996, Born 3-13-06 Adopt 5-17-06
Tire wear rule of thumb
[quote=wildcat66]I know we have talked about this before, and no this isn't about what size, type or brand. This is about the front and rear wear effects and what we need to do about it.
I have 19k miles on my truck, I have already said my rear tires are wearing in the middle
In general this is an indication of over-inflated tire pressure. Second, this could be the tire construction? With 20" tires on back of vehicle with wide tread pattern and possibly not using on highway driving most of the time it is a normal wear. Another cold hard fact is that the higer the speed rating less mileage.
Please remember going lower on speed rating can couse handling problems.
over the weekend I checked the front and they are wearing on the inside. Almost to the point of no tread left.
In most case this is caused by excessive toe out wear. With the onset of larger tires diameters and widths and frame construction the old rule of thumb was
put out to pasture. So, IF your the 90% driver and weight less than 175lbs
your service technician should change camber to more positive. Plus set the toe to 1/32" in total.
I am calling my service rep today but I think this really needs to be addressed by GM.
The use tire depth gauages could have eliminated the problem a long time ago if somebody when service your vehicle looked at tire wear problem. Fast lube places are not trained to look at tires because all four are on the ground.
Hope this helps to understand the problem and the cause.
It seems to be a problem with the C6 Corvette as well, I wonder if Goodyear changed the rubber compound or something. People are complaining about badly worn tires at 15K miles
Freezer: This is not an isolated case. My own SSR, and countless others, exhibit this same set of symptoms, even though tire pressure and alignment are well maintained:
1. Rear tires wear in CENTER of tread much more than edges (MUCH more)
2. Front tires wear a LOT on the inside edges
I took mine in for an alignment just 2 weeks ago, and the technician reported that it was off only the tiniest amount.
Freezer: This is not an isolated case. My own SSR, and countless others, exhibit this same set of symptoms, even though tire pressure and alignment are well maintained:
1. Rear tires wear in CENTER of tread much more than edges (MUCH more)
2. Front tires wear a LOT on the inside edges
I took mine in for an alignment just 2 weeks ago, and the technician reported that it was off only the tiniest amount.
There are GM issues here.
Jim G
The front end alignment is, at best, a trade between tire wear and vehicle performance. You want more performance, you'll get more wear. An example would be an autocross car may have about 2 degrees negative camber for the best handling. You wouldn't want this on the street since you'll kill the inside of the tire in short order.
The obvious fix is to go with less negative camber in the front. Of course you'll be sacrificing some handling performance the next time you go around a corner.
In regards to the post that mentions the toe setting (out) causing the wear. Yes, toe out will cause this type of wear but is easily identified by a darty front end. In other words, the truck want to go everywhere but straight. Not by a big amount but you would be constantly making steering adjustments to go straight. It's a neat trick on an autocross course though.
I'm not too surprised by the wear on the inside of the front tires. This will be more prevalent on SSRs that are driven easy or mostly on the interstate.
Reason is the front alignment calls for about 1 degree negative camber which will cause that type of wear.. The only thing that masks it is to wear the outside edge of the tire by pushing it around the corners...
With the 1 degree neg camber.......this will happen on this truck......Look at it at rest.....Front wheels look nocked- kneed...........and as you drive it becomes worse and when any braking occurs....it gets alot worse..........My suggestion would be to stand it straight up...... and try it .........it can't be any worse than what we get now!
I take mine to the dealer for every oil change. It is almost time for another.
This is one area they should have been checking but it has amost been 3000 miles since last oil change and I have no way of knowing how long the tires have been this way.
I'm not too surprised by the wear on the inside of the front tires. This will be more prevalent on SSRs that are driven easy or mostly on the interstate.
Reason is the front alignment calls for about 1 degree negative camber which will cause that type of wear.. The only thing that masks it is to wear the outside edge of the tire by pushing it around the corners...
Inside tire wear isn't a result of an improper alignment, but the fallout for an alignment optimized for handling vice tire wear.
To really discuss this issue, can someone with a service manual look up the actual alignment specs. As an example, here are the specs for my 2002 Corvette Z06:
Z06 Specs:
Front Individual Toe: +0.04 degree +/- 0.10 degree
Front Sum Toe: +0.08 degree +/- 0.20 degree
Front Individual Caster: +6.9 degree +/- 0.50 degree
Front Cross Caster: within +/- 0.25 degree
Front Individual Camber: -0.70 degree +/-0.50 degree
Front Cross Camber: within +/-0.25 degree
Rear Individual Toe: -0.01 degree +/- 0.10 degree
Rear Sum Toe: -0.02 degree +/- 0.20 degree
Rear Individual Camber: -0.68 degree +/- 0.50 degree
Rear Cross Camber: within +/- 0.50 degree
As can be seen from these specs, the nominal front camber of the Z06 is -0.7 but the tolerance is large, such that anything from -0.2 to -1.2 is "in spec". Vette owners desiring better tire wear at the cost of handling can skew the alignment but still be within factory specs. To minimize front inside edge wear for a daily driver, set the front camber to the least possible, e.g. -0.2 for the Vette, and front toe to zero.
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My SSR: 2003 Redline Red #0733 Born on 10/20/2003 Arrived home 11/26/2003
Tire Wear
I found tire wear at around 10,000 miles to be abnormal, centers of rears were wore in center and front tires were wore on inside only. Dropped all four tires pressure too 28 psi and had front end aligment. Checked tire wear about every 2000 mi. after that. Lowered the truck at 14,500 mi. and had realigment done. Have over 17,000 miles and all tire wear has held steady with no more abnormal wear of fornt or rears.
Inside tire wear isn't a result of an improper alignment, but the fallout for an alignment optimized for handling vice tire wear.
To minimize front inside edge wear for a daily driver, set the front camber to the least possible, e.g. -0.2 for the Vette, and front toe to zero.
Yup. He's on target here.
Marauder owners experience exactly the same problem. Abnormal wear on the centers of the rears, abnormal inner tire wear on the fronts. And these are on cars based on the Ford Panther platform (Crown Vic, Grand Marquis) that routinely run 40-50K miles on a set of tires with even wear.
The Marauder's front alignment specs are set to improve handling, and because of this, the car rides on the inner part of the tires more than a "stock" Panther. Also, 18" wheels and wide tires don't help. The rears are also wide and on 18"s. Front and rears are BF Goodrich KDWS or KDW2.
These tires have soft rubber compounds, and I assume the Goodyears on our trucks have a similar compound. Goorich says 15-18 K on rears and 20K on the fronts is normal wear. There's even a Volvo VR-40 ad that says right in the ad you can only expect about 18K wear on the tires. I will be very, very happy if I can get over 20 K on the rears and 25 K on the fronts.
On the BF Goodrich forum a tire enginger suggested that >increasing< tire pressure in the rears was the answer...
"However, take it from me as a Tire Designer (6 years) and Ex-Test Driver for BFG (6 years), rear wheel drive, high horsepower, and high torque applications that exhibit accelerated center rib wear usually benefit from INCREASING cold inflation pressures. Now I know absolutely everyone in the public domain will tell you accelerated center rib wear is caused by over inflation, but believe me it's also caused by under inflation on the 'driven axle' "
Some Marauder owners reported that inflating the rear tires 6-7 psi above the door psi spec did result in better rear tire wear.
My SSR: '03 Redline Red #1377, cooled by Simple Engineering
Quote:
Originally Posted by hdflstf
I'm not too surprised by the wear on the inside of the front tires. This will be more prevalent on SSRs that are driven easy or mostly on the interstate.
Reason is the front alignment calls for about 1 degree negative camber which will cause that type of wear.. The only thing that masks it is to wear the outside edge of the tire by pushing it around the corners...
That explains why I have even wear. I use ALL of the tire.
Seriously, though, I'm at 14,000 miles and I don't see any uneven wear on the front tires, but I may very well be "masking" the wear by pushing the SSR a bit in cornering. There's a hint of center wear on the rear tires, so I'll boost my rear tire pressure to 35 PSI and keep an eye on it.
mcvett2 was kind enough to PM me these specs for the 2003 SSR (and I assume they haven't changed much through the model years):
Base settings; Caster left & right 4.25 +/- 0.50
Cross Caster ( L - R ) 0.00 +/- 0.30
Camber -0.50 +/- 0.50
Toe +0.10 +/- 0.20
Caster should be set max positive and matched side to side, but will have little impact on the discussion here.
Camber spec is for a nominal of -0.5, but anything from 0.0 to -1.0 is "in spec". Those desiring better wear should request camber be set nearer to zero than to -1.0 for the front.
Nominal toe is slightly out (positive), but anything from -0.10 (slightly in) to +0.30 (toe out) is "in spec." When combined with negative camber, toe out (or in) will increase inner edge wear. A slight toe out will improve turn in and reduce understeer, which is why the nominal spec is slightly out, but 0.0 is in the allowed range. Those desiring to improve tire wear should request front toe of 0.0.
A good alignment shop should be able to hit the desired mark within a tenth.
Me... I'm on the other side of the spectrum. As soon as I got my Z06 I set front camber to -1.75. I wore out my stock front tires in 3,000 miles.
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Widcat, keep us informed as to what you find out. Thanks.
GM has screwed up....!
Tire Wear
