I have a 04.5 GMC 3500 Diesel Dually with 17k miles on it. I have been through 4 sets of front tires. The fronts are cupping severely. I have tried running the fronts at different tire pressures and this is what I have heard....

Run them at 55psi and the tires cup b/c you are not riding on entire tread. (Discount Tire)

Run them at 75-80 and the tires will bounce causing them to cup (GMC Dealer)

Regardless, my front tires are toasted after about 1500 miles.

Anyone have any other ideas on what might be causing this. I have had it aligned 4 times and each time they make a small adjustment but they say it is not off enough to cause this.

Last time, dealer sent it out to be aligned and when I got it back one front had 60 psi, the other had 75psi and they changed alignment again.

Please help, I can't afford front tires every 3 - 4k miles and I don't want to rotate every 1k miles to save them! After about 3k miles the tires are so bad that they shouldn't be rotated to the back, b/c it will cause one rear tire to have excessive pressure on it and risk a blowout towing my trailer.

Have run: stock tires from GMC, 2 sets of Pirelli Scorpion A/T, 1 set of BFG a/t, same deal.:eek:

Don't know what your tire problem is :confuzeld , but I would be looking at the dealer to fix it right because there is no way a tire should be worn in 1,500 miles. You obviously have a problem with the front end that needs some work. And the fact that your tire's had diffrent air pressures when it came back from the alignment shop show's that they don't know what their doing. The first thing to do on a alignment is check the air presure and set it correctlly and the SAME on each tire on the axle.
Try to find a better alignment shop that works on 4x4's and larger truck's.
Don't let the dealer push you around, you have a problem with the front end somewhere that needs work.
8 tires in 17,000 miles is -:t

Good Luck

Diesel Dragon

Try a different dealership if one is close by. If no joy there contact GM directly. Pretty evident that the dealer you went to is having help problems.

Jack up the front end and turn (spin) the wheels to ensure they are "free" and not dragging from something being in a bind (brake calipers dragging, front diff. problems, bad wheel hub, etc.) The mechanics are bound to missing SOMETHING.

Is it 2wd or 4wd?


Gary

Go buy 6 new load E tires. Have balanced and installed. Fill to reccomemded psi.

Replace all 4 shocks with Biilsteines/Ranchos/Edelbrocks

Have 4 wheel alighnment done at new dealer. Do not mention any past problems. Replae all parts reccomemded if any by technician/.

Drive, be happy.

Rotate/balance every 4000 miles.

Inspect tread wear. If low in center, lower air pressure by 10 PSI. If low on outsides raise ari pressure by 10 psi.

Most likely front psi will be higher then rear unless you are a heavy loader/tower.

Drive be happy. Good luck.

I will jack up the front end and give it a try, but I think I would hear that, or feel it on slow roll.....

This truck is awesome except for this problem which has been happening since day 1.

The dealership is being pretty cool, they keep taking it in to try other things, but they just tell me, rotate the tires and then wait to see if it still does it after awhile, and it does. The hard thing is having to take it in every month or so, I have a to go to work everyday!! I am running out of days off to take the truck in!

The tires are load E, probably could use some new shocks, heard a lot about the Bilsteins, maybe I can get the dealership to pay for them, haha.

Go buy 6 new load E tires. Have balanced and installed. Fill to reccomemded psi.

Replace all 4 shocks with Biilsteines/Ranchos/Edelbrocks

Have 4 wheel alighnment done at new dealer. Do not mention any past problems. Replae all parts reccomemded if any by technician/.

Drive, be happy.

Rotate/balance every 4000 miles.

Inspect tread wear. If low in center, lower air pressure by 10 PSI. If low on outsides raise ari pressure by 10 psi.

Most likely front psi will be higher then rear unless you are a heavy loader/tower.

Drive be happy. Good luck.
Bronco,
That would be great for a guy that's out of warranty, but in this case I think the dealer should be doing more to help the fella out...There is no way those tires should be wearing that fast unless he's rounding corners at 90mph....

uhoh...90mph...didn't think about that, haha

Well, I do live on an excessively windy road, but I am usually pretty good about the corners.

I just don't know what to tell the dealer to check any more, they did the alignement soooo many times, they found a bad shock mount once, that took care of a squeek, but the tires wore faster when I got it out after the alignment and fixing of the shock mount.

By the way, going back to my original post, what would cause cupping across the enitre tire, under inflation or over inflation? I have been told both ways, what should the fronts be at for E rated tires? It's like every 4th or 5th tread is way lower than the rest , you certainly can't run your hand over the tire tread with out your hand bouncing all around.

I would have the tires balanced by a tire shop that has a road-force style balancer.....I would think that if this is an alignment issue, you would have wear on either the inside or outside of the tire, not all the way across.....
Balancing and air pressure sound like the key here, but I've been wrong before....

road force tire balancer? Who would have such a thing and what is it? What do you think my pressure should be? thx partsguy

road force tire balancer? Who would have such a thing and what is it? What do you think my pressure should be? thx partsguyMost good tire shops have them...If you're in a large area...(the machine costs somewhere around $10,500 :eek: In other words, a mom & pop tire shop in a town of 2000 people probably isn't going to have one.... Basically, it's a balancer with large wheel that goes against the tire being balanced.....
I would ask the tire shop what they recommend for tire pressure too...If you deal with a tire shop that deals with 3/4 ton and 1 ton trucks often, they should know what works for tire longevity....

I wouldn't think tire pressure or balance would have anything to do it, as far as that goes the alignment either. It sounds to me its a shock problem. If you're cupping all the way across the tire.... definately a shock problem. If you want to check it out just buy an inexpensive set of shocks to try... if it helps then upgrade to Edelbrock, Rancho, or even Monroe Reflex shocks.

Have the dealer look at the steering, cupping is usually caused IMO by odd geometry during turning. Seen it in my 4X4's for years. If you drive at low speeds (parking lots) and not much straight driving you will eat tires fast. Not much that you could do there. :(

Oh yeah, stock shocks are only good for the tail light warranty. (that's when they can't see your tail lights anymore.

Thnx guys,

I will have them check the steering and alignment again on Wednesday. Probably will upgrade shocks as well. I have heard many many people going with the bilsteins. I guess i will have to give it a try, wifey poo isn't going to be happy about the extra dollars...just spent a bunch of money on other things like the edge, intake and exhaust, oh ya and DVD system and navigation, etc. etc. I have been promising her all year that I would get her windows tinted on her car. haha should probably do that first, otherwise I may be sleeping in the bed of my truck.

Sounds like a caster/camber problem. Could be a bent spindle, had that problem on a 98. Have the frame checked for straightness.

Try to spin balance just the wheels to check for them being out of round. Cupping is from the tire osolating,sp?, bushings and or shocks being bad or something out of round.
How smooth is the truck when your driving? Any shaking or anything? Drive a new truck just like yours to see if you notice anything off or odd about the way it handles. I am a corner carver and that only wears the outside edge of the tires faster so I doubt thats it.

The truck seems to drive just fine, maybe it is bouncy on the front, but I wouldn't know since my last truck was lifted 10" with 38" tires. This truck is stock, but it seems to drive just as smooth as my Tahoe. The back is stiff because it is a 3500. The steering wheel does not shake or anything, i would think that it would with the front tires being as bad as they are.


At least I am getting some great ideas to tell the dealer when it goes back in for the 6th time on Wednesday. I am going to have them buy me new tires then have them look at everything again and wait to see what happens. The tough thing about this is that you have to wait 1000 miles to see if the fix actually fixed it.

Get a true 4 wheel alignment (six wheel???):)

The scalloping is caused by the front and rear axles not being totally square to each other, combined with the positve toe settings. If your dealer can't do it, have them find and pay someone reputable who will. (My Dodge dealer still can't align my Cab & a half Rams., the rack is too short.) If the dealer is stubborn, try a medium duty dealer (even though they are harder to find.)

Don't let any one BS you. 10Ply rated tires in my overworked, extra abused fleet of trucks still last at least 18,000mi (that was OEM bridgestone R4S 10plies, they wore out in the center because the dealer said 32 psi in 10 plies.:mad: )

Tires cup because they are bouncing up and down uncontrollably. Since you have had several sets balanced by different places that leaves the shocks or lower ball joints. The joints are tough but the shocks are junk. You haven't by chance screwed the torsion bars up too far? Shocks alone cannot hold the tires on the road. Caster/camber/toe has nothing to do with cupping. Later! Frank

No, I have not upped the torsion bars just because of this potential problem. One this is unclear to me though...when i first got the truck, the screws for the torsion bars were equally set. Now, after numerous alignments, the driver side is much farther in than the passenger side. Any ideas why they would do that?

The technician did that. There is an alignment spec for ride height. So he is just trying to make things right.

So it sounds like it is probably the shocks, has anyone HAD to replace shocks this quickly. The truck only has 17k miles on it. I would think that GMC would place shocks on the truck that work. Maybe I can get GMC to spring for an upgrade to heavier duty shocks, but I doubt it. Just seems a shame that I have to pay to replace inferior stock equipment.

I am going to have them check the spindles, 4 wheel alignment and balancing again this week. It's always a wait and see game as it takes about 1000 miles to see if the fix worked.

replaced my shocks at 5k

I did not change mine until 37K. I should have done them a lot sooner. One shock was actually seized up in mid travel. That side tire was cupped a little and the alignment was screwed up too short to hang up. Doesn't say much for an ex-front end mechanic does it? My last truck was a 99 Silverado. I had one front and one rear leaking at 15K. Later! Frank

i had the same problem and i fixed it.
im not saying i did it the right way, or by any means the best way, but i did stop the tire chop.
1. new shocks Bilstein
2. Adjust front end up, almost bottomed the bolts out, leveled side to side as well truck never bottoms out anymore over hard bumps.
3. wider tires. i went with 265/75 up front and 235/85 in the rear. same size tires for the 4x4 and the front end rides alot better.
if i broke all the rules of truck maintence so be it, it worked for me.

Guys with bad shocks, help me out a little here. Why did you replace them???

I have seventeen trucks in the fleet (2500's and 3500's 4x4's) and have never replaced but 9 shocks in 1.7 million fleet miles on my GM trucks. When each truck gets new tires, the old tire are inspected for wear patterns, and most have very little any cupping. ( I do see some more than others with shoulder wear and/or over/under inflation wear.) What am I missing here???

And, YES, I do drive all of them to evaluate their condition twice a year and also, as a construction company, we are obligated to romp, smash, overload, and generally abuse the trucks. We also keep them til 180,000 miles or so, and I just sold a '99 1500 with 264,000miles and the shocks were changed at 202k because the bushings in eyes on each end went south but the valving and still functioned.

I'm not saying your shocks weren't bad, I'm just curious how they were determined to be bad? Maybe I'm missing something (wouldn't be the first time.)

drive your 2500 hd and then put on some bilsteins and then drive it again and get back with us, I think you will find out why we change them!!!

Why did i replace them? cause them bilsteins look darn good on the truck! what i found after removing the stockers was all 4 worn to the point where if pushed it would only resist for 1 - 1 1/2" then push completly in with just my forearms.

heymccall,

I don't know if the shocks are bad, maybe they are maybe they aren't...we haven't determined that yet. We are trying to figure out why my tires are cupping so bad, within 1500 miles. I have been through 4 sets of front tires in 17k miles.

nrgreen, have you taken a good look at the body lines of the truck to see that the bed lines up with the body? I would also take it to a frame shop and have the frame checked.

I build these trucks and I can tell you that there has been several times we have had difficult times putting the suspension parts on the frame due to a misaligned frame. What I mean by that is frames that were not welded together correctly. But GM has standards. If they get through roll test and toe-in (alignment), they get shipped to the dealer for sale.

So my biggest recommendation is get that frame checked.

hey Crazydaze, now that makes sense, i will have that checked as well, maybe I can go for lemon law?

I don't understand, you got a truck under warrenty and your having all this stuff done? Drop it off at a dealer and tell them to fix the damn thing!!! I hope you did not pay for all these tires?

That is going to happen this week, I am so glad everybody here has given me ideas, so that when I take it in next time, I am going to give them the list of things to check.

4 times they have changed the alignment and said, ok, we have to wait and see if that helps. So I have to wait about 1500 miles before it becomes evident that what they did, did not fix the problem. Once they replaced the shock mount, haha, ya that'll fix it.

I just picked my 05 2500 4x4 from the dealer yesterday for an air leak around the extended cab doors. They replaced both side glass in the doors. I was inspecting the truck before I left the dealer (heard too many horror stories i guess) and I noticed the right front tire was cupped all the way across the tread. I only have 2800 miles on the truck and have not used the 4x4 yet. All miles are freeway and street only.
I showed the service writer and on the way out to the truck he said< "yeah I seen this before on the 2500 and 3500's not sure what the problem is. In fact I have a cusotmer with a 3500 4x4 dually that has the same problem and the poor guy has been in several times. So far he has been a sport about it. But we need to get it fixed."
Now hows that for building confidence in a dealership?
I have made an appointment for next week to have the service manager "take a look"!
I guess he will wave his hands over it and pronounce it cured!
Now I read Crazy Daze write about bad frames from the factory! great I gotta stop reading here so much LOL

Hey Bruce, are you in North San Diego, maybe Esco? That sounds like me! Also, I couldn't make it in for my appointment, waiting until next week, let me know what happens with yours. I have been in about 5 times. Maybe the both of us can work the problem! I am sure we are at the same dealer.

yep Nrgreen

the same dealer and same service writer. I too didn't make it this week. Thinking about a frame shop. I'll let you konw

well bruce, you inspired me to call again, i too think I will have the dealer pay for a frame shop to check the frame. That is strange that yours is doing it on only one side, mine is both, love the truck but hate this problem! We'll keep each other posted!

Hey guys I'm in North County I have a suspension and frame shop that can handle C/C L/B's maybe I could take a look at your trucks I'm 1 mile from Quality :banghead: Chevy. P/M me but, early next week would be the soonest I could fit you in. I feel your pain you have to hold their hand every step of the way. I just wrote a (detailed) fix it list for my local dealer. Let me know if I can help.