Alignment problem, need some ideas.

[Ian Turgeon]

When I installed my coil overs 2 years back I had taken the truck to Sears for an alignment...

The machine's specs were dead on, and it pulled to the right. I didn't have time to deal with it then so I went on my way... however, while at the shop I noticed my rear tires were wearing heavily on the inside shoulders.

I was headed to the 1/4 mile strip in Bradenton, when I realized both rears now show critical wear on the inside shoulders (both tires had globs of rubber much like pencil eraser bits) after a 150 mile drive to the track.

Now, the new tires are showing the same wear pattern - although it seems slower. Having not driven it much and not really knowing how to diagnose the problem Its gone unfixed, but its time to figure it out.

My first suspicion is that the rear tires have magically developed either camber or toe, but even if I can verify this how the hell would you fix it on a solid axle besides replacement?

Mods:
Front: QA1 coil overs & JSM Arms
Rear: 2" blocks, bilstiens, (just added a Belltech sway bar)

Anyone have any ideas? Is there some place I should take it, just another alignment shop or something better? I don't know if theres any options other then wheel and tire shops.

 

[TYTILIDIE]

Re: Alignment problem, need some ideas.

Ild check your alignment nuts/bolts/clamps. Ive had alignment shoopps not tightens things TWICE!!! I would also hold hte wheel straight, drive, then push the ebrake til you stop, get out and see if your wheels are screwed up. This is how I do my alignment. It usually takes me an hour or two but is better than nay alignment shop Ive ever been to. Also make sure you do this test in a flat parking lot or driveway.

 

[SYO237]

Re: Alignment problem, need some ideas.

everything on the rearend is tight as far as bolts go. its quite odd to see the centers of the rear wear out. Tire PSI is also where its supposed to be. driving behind or next to ians truck, there is no apparent or visible wooble motion if it was a bent axle. could put it up on jackstands and try to double check if needed.

would something loose up front actually cause rear tire wear as bad as this?

 

[TYTILIDIE]

Re: Alignment problem, need some ideas.

Wait a second, what tires and wheels is he running? I have Z06 wheels and sumitomo tires on the back and htats how mine wore. I just read the post agian and realized. My wheels are 18x10.5? on the rear and the tire I run is a 285/35/18 HTRZII Sumitomo.

 

[JSM]

Re: Alignment problem, need some ideas.

Get a 4 wheel alignment, odd the rear tires are having problems though.

 

[SYO237]

Re: Alignment problem, need some ideas.

Need more info, and might have some input:

What size rear wheels and tires?
What tire pressure do you run?
What is rear wheel offset?
Are you running wheel spacers on the rear?
What is the "Treadwear Number" on the sidewall? (Lower than about 240 is a pretty 'soft' compound).
Does it 'crab and jump' at 'parking speed' with full front wheel left or right?

Let us know.
DaveP

Hey Dave...

I can answer some of these...

This was happening on the stock rims, stock tire size with Kumho Ecstas.
35psi I believe in the rear

Only since about 3 weeks ago is he now running 17" Z06-Rs all around with 1.25" spacers out in the rear (standard 17x9.5 vette rim) that came off my truck since I got new rims.

 

[JSM]

Re: Alignment problem, need some ideas.

The alignment being "dead on" combined with rear tire wear is telling me something is not right with the rear. Maybe the alignment pins are not lined up, sheared off, not located correctly, bent spring...

A good alignment shop can do a 4 wheel alignment and tell you what is off and where. Sears is not a place I would let do anything to even my lawnmower. I think the techs there are reject dealers guys.

 

[QWERTYphoon]

Re: Alignment problem, need some ideas.

Ya, I would say put it back up on the rack and align it again using the stock wheels. Show us so pictures of how you have your rear sway bar attached. What rear shocks are you using? Does it make any funny noises? When you turn? Loud on highway? Stock leafs? Any missing or taken out? Frame damage? Sounds to me like your axle is not staying centered? You should have uneven tire wear on the outside too, not even air pressure?

 

[Black Knight]

Re: Alignment problem, need some ideas.

Get a 4 wheel alignment, odd the rear tires are having problems though.

It doesn't matter what shop he takes it to, no one can do a tradional 4 wheel alignment because there is no rear adjustment. All he's going to be able to get is a thrust angle (just the front end adjusted). Which isn't going to help the rear at all.

If the alignment pins were off or anything shifted the tech would have seen this. He would have had to compensate caster for the fact the axle had shifted. Which I can't imagine why he would tell you it's perfectly in spec if that had to be done.

Ian if you have a copy or can get another copy of the alignment specs I can tell you if that's your probelem or not. Only a couple things it can be. If the rear axle bearings were bad it could cause inside were, but you should definitely hear it and it probably would be leaking axle fluid. Other then that we just need to know what the rear toe looks like. You don't have a uncommon rear setup to be having a problem from it.

Ild check your alignment nuts/bolts/clamps. Ive had alignment shoopps not tightens things TWICE!!! I would also hold hte wheel straight, drive, then push the ebrake til you stop, get out and see if your wheels are screwed up. This is how I do my alignment. It usually takes me an hour or two but is better than nay alignment shop Ive ever been to. Also make sure you do this test in a flat parking lot or driveway.

I'm sorry Mike, you know I respect you, but that's obserd buddy. You would be way more accurate if you bought one of the tools off Summitt and a tape measure :tup:

 

[TYTILIDIE]

Re: Alignment problem, need some ideas.

I'm sorry Mike, you know I respect you, but that's obserd buddy. You would be way more accurate if you bought one of the tools off Summitt and a tape measure :tup:[/QUOTE]

Laugh all you want, it works and it works well. I also use a level. I knwo it sounds lame but seriously, better than any alignment shop Ive ever been to.

 

[SY2455]

Re: Alignment problem, need some ideas.

Another area to check is the center section where the axle tubes join the carrier. Not sure how to type it, but make sure they are parallel. I had one that was starting to come apart, but not leaking yet. When I unbolted the rearend the driver side tube was being held in place by the C-clip. I don't know if this will help, but I would look. There not alot that can go wrong with a rearend of the type we have to cause this.

 

[Ian Turgeon]

Re: Alignment problem, need some ideas.

Ok, let me try to answer the questions.

Rear Suspension: Stock Wheels, Kuhmo Escas ~320 treadwear, (~30 psi to even rolling diameter with fronts) stock springs, stock axle, 70k original Bilstiens, 2" lowering blocks. The problem was present before the sway bar, so it should be removed from the equation for now.

I don't think the fronts are aligned right, I have to get them done anyway, but just wondering where the hell to take the thing. Sears is pretty much on par with everything else I've been to (Tire Kingdom, Sears, Goodyear (they used strings)).

The truck does scrub and jump on hard turns sometimes.

The perplexing thing is every theory I have is disproved or shouldn't exhibit these problems.

Any mis-alignment of the rear axle SHOULD result in equal and opposite wear on the rear tires (inside on one, outside on other), this would cover lazy springs, broken pins, loose bolts, etc. Axle bearings should leak and or make noise, but I have neither issue.

Back of the mind ideas:
Rear diff screwed, causing scrubbing on turns on the insides only.
Bent Axle so that the axle is either bent downward or forward/back.
Domed roads everywhere that cause more wear on the insides of the tires.
Tire biting gnomes that enjoy the inner shoulders more?

I guess its just gonna have to go to a good shop and tell them about the issues i'm having, have them measure the rear wheels and double check the fronts. I'm just so distrusting of these guys being able to diagnose it correctly.

As mentioned, has 4 matching Z06R's now with new front Kumhos and nearly dead used rears showing lots of wear on the shoulders from their former life.

 

[TYTILIDIE]

Re: Alignment problem, need some ideas.

I have one more question for you. When you had your tire on there new, and youre looking at it from the tire view(cant see the rim) did the tire look like it sagged toward the middle? This is how mine is and oddly enough, the center of the tread is what wore down even thgouh it barely touched the ground.

 

[canadian]

Re: Alignment problem, need some ideas.

are you sure the rear isn't cocked at all? one side closer to the front of the truck versus the rear? measure from the center of the axle to the front spring perch on both sides and see what you get, or diagonally to the opposite rear frame rail and see what happens. just a thought.

 

[Ian Turgeon]

Re: Alignment problem, need some ideas.

These guys sound promising... I'll probly do some measuring and head down there this weekend.

I'll be sure to report in.

http://www.tirerack.com/installer/I...nstallermiles=5&zipCode=32725&x=0&y=0&place=0

 

[Loeryder]

Re: Alignment problem, need some ideas.

I talked to the local lowrider truck guys and took my truck to the guy that aligned their airbagged trucks.
While they did do a fine job I didn't particularly like their attitude.

I brought in my own specs and asked for the -.2* "enhanced" specs and they didn't want to do anything but 0* factory settings, which I had to argue that my truck was not the same spec as a 4x4 jimmy (what it came up as in their computer).
All I asked was that I be able to see my truck at all times and that only the manager road tested it with me in the truck.
They refused to let me ride with them b/c of insurance accountability so I told them to not road test it and they wrote on my receipt that I refused to let them "verify" the alignment was performed correctly so I couldn't go back and make them tweak it.

I told them if they couldn't get it right off the laser alignment machine that road testing it wasn't gonna tell them squat.
So we parted ways on a bitter note, but they do the areas lowest trucks supposedly.

The local lowrider guys will have a preferred alignment shop.

 

[Black Knight]

Re: Alignment problem, need some ideas.

Could be a bent axle, not so common on our trucks, but your symptoms are the same as say a boat tralier with a bent axle. Extreme inside wear, scrubbing, but they should have seen that the camber was screwed up when they did the alignment. Unless they didn't even bother to look at the rear camber becasue the person doing the alignment knew there is no adjustment. Depending on the machine it doesn't require you to look at the rear specs, it can just shoot you straight the front, becasue it also knows there's no adjustment.

 

[dgoodhue]

Re: Alignment problem, need some ideas.

If the measurement are made right and someone take they time to make sure both sides are equal (not just in spec) it should go straight.

My only thoughts on this truck is something funky going in the rear end (Mounting location, warped/bent axle) or maybe the front some how is messed up that its causing odd thing to happen in the rear.

 

[canadian]

Re: Alignment problem, need some ideas.

so whassa word?

 

[Ian Turgeon]

Re: Alignment problem, need some ideas.

Took it in Tuesday and the guys advised me to get the front solid before they even bother trying to measure anything.

Front wheels move side to side and a little bit up/down. They recommended upper ball joints and pitman/idler arms. They were also baffled at what could cause the rear tire symptoms besides axle problems.

My only concern is that I don't know if it will ever really be solid side to side, I mean theres 6 ball joints in the steering... if I do one whats to say I shouldn't do them all (inner/outer tie rods, pitman, idler, center link) They offered to place a spreader (like they do for Mercedes apparently) between the fronts and do it that way, but the driving dynamics would change all the time with the wheels having play in them. They tried to show me the movement... The wheel moves side to side a bit, but looking at the joints I didn't see all that much movement in any particular joing (talking 1-2mm).

I'll be doing a steering box in Miami at the end of the month, so I guess I'll tackle the rest of this down there.