Front tire wear = worn suspension?

[nutshell]

Hi guys. Here's a puzzle.

Further to my recent post made under "AWS - myth or miracle"

Recently discovered my outside front tire was badly worn on the inside edge-after only 35,000 kms - images are attached of the wear.

A laser align checked out A-OK. Everything within tolerance according to the machine. Replaced the tire.

The vehicle is a R/hand steer '91 CXD AWS with 198,000km on the clock.

Has anyone got info on how to check for wear in the lower control arm bushes?

Thanks,
Ian

[viking64]

looks like the tyre has been rubbing - more wear in one spot than even accross the surface. Is it both sides on front or just one side?

[wannarace928]

I have not had control arm bushing problems on my subaru but on another car I have, I did have a problem similar. It would eat up tires like no other, unusually within 5k-10k miles the belts would be showing on the edges. Once it started to eat away at the tires it would make the front end wobbly like it needed balanced. It would also make cracking noises when stopping suddenly do to the weight shifting.

[gsodonis]

I have experienced the exact same wear - and on two sets of tires. When I first bought the car, the PO had put 18's on it, but with a good camber correction kit. The two fronts were gone at 25K miles of use, but only because the cord wore through on the inner most edge; the rest of the tire had a good 10K miles left on it. I wrote it off as running the tire possibly too low on air and misalignment. I bought a lifetime alignment from Firestone and they showed me that front toe was out on both sides. I replaced the worn tires with a set of new Firestone Wideovals - great tires by the way. At 25K miles, I noticed that the inner edge was wearing thin again. I took it to Firestone and they did an alignment again for free - gotta love that lifetime alignment - and said that the toe was out again. Not as bad as the first time, but enough to prematurely wear the fronts. Because they had performed the last alignment less than a year earlier, they prorated the two worst ones and replaced them with new. The manager recommended that I come and get it aligned every 6 months from now on. The rears by the way looked perfect and have at least another 10K left on them - not bad for 18" rubber. According to the manager, the alignment checks out to spec, but his analysis is that the suspension bushings have lost some of their strength and elasticity. If I have him check and tweak the alignment every 6 months, I can get the most out of my tires without doing a suspension rebuild. Outside of that, If I want to make it right, I probably need to replace a bunch of bushings. If I could get them in urethane, I would. By the way, I have a 92 with 140K miles, so it's a plausible explanation. Rubber bushings don't last forever. I hope this helps - you are not alone!

[SSSVX]

Originally Posted by gsodonis

I bought a lifetime alignment from Firestone ...

How much is your lifetime alignment? It's nice.

Lifetime as of what? As that set of tires? As per car? Or as of your life?

[gsodonis]

Originally Posted by SSSVX

How much is your lifetime alignment? It's nice.

Lifetime as of what? As that set of tires? As per car? Or as of your life?

At the time I got my alignment, Firestone's one time deal was around $40 and like $100 for a lifetime - as long as you own your car. When I bring it in and they lift the car, I get to crawl all over it and do my own visual inspections of the undercarriage and thing you normally can't see without a shop lift. Worth the price for a older car IMHO.

[Trevor]

Originally Posted by viking64

looks like the tyre has been rubbing - more wear in one spot than even accross the surface. Is it both sides on front or just one side?

I agree. The damage appears to be so specific. Something narrow has been in contact with the tyre as it has rotated.

[oab_au]

Worn lower A arm bushings, allow the wheel to move forward, under drive. As the rack is in front the ball joint, it steers the wheel out, as it moves forward, to wear the inside edge.

Harvey.

[Trevor]

Originally Posted by oab_au

Worn lower A arm bushings, allow the wheel to move forward, under drive. As the rack is in front the ball joint, it steers the wheel out, as it moves forward, to wear the inside edge.

Harvey.

The extraordinary tyre wear illustrated, would require extreme ball joint play, such that the car would not have been granted a warrant of fitness.

[nutshell]

Originally Posted by oab_au

Worn lower A arm bushings, allow the wheel to move forward, under drive. As the rack is in front the ball joint, it steers the wheel out, as it moves forward, to wear the inside edge.

Harvey.

Harv, that's my thought too. But is there an "easy" way of establishing if there is wear in the lower control arm bushes? i.e. a leverage point to apply a pry bar to view any movement perhaps? Are replacement bushes available?

Trev , the wear is pretty constant around the circumference. The vehicle has been religiously maintained by Winger - the local agent - for the last 7 years.

Ian

[Trevor]

I gather winger have been issuing a warrant of fitness. If so and they have not detected the sort of play in a bushing required to cause the damage pictured, they should have their license suspended. VTNZ who I go to, always apply a pry bar as you suggest, if they have any doubts concerning a soft bushing.

[SURTEESS]

Hey Nutshell (Ian) & Trevor since you are in Auckland, you are both more than welcome to paw through the service manuals that I got from USA (ok so LHD) approx 8" wide across spine!!! - I'm based at Torbay, on the North Shore.

Shows most things - but being from USA does not show AWS, front headlight wipers & sprays & light levelers (remote switch by gear selector), rear window ioniser (remote switch by gear selector) + couple of other things that I cannot remember about......

phone me on (09) 473-7199 or mob 027 290-2361

Steve
(red 1995 with moonroof, full leathers & 125,000 on the clock)

[Trevor]

Originally Posted by SURTEESS

Hey Nutshell (Ian) & Trevor since you are in Auckland, you are both more than welcome to paw through the service manuals that I got from USA (ok so LHD) approx 8" wide across spine!!! - I'm based at Torbay, on the North Shore.

Shows most things - but being from USA does not show AWS, front headlight wipers & sprays & light levelers (remote switch by gear selector), rear window ioniser (remote switch by gear selector) + couple of other things that I cannot remember about......

phone me on (09) 473-7199 or mob 027 290-2361

Steve
(red 1995 with moonroof, full leathers & 125,000 on the clock)

Thanks a lot Steve,

I have a full set of JDM RHD manuals in English and likewise call me at any time. I am in Waterview. (09) 820 8553

[nutshell]

Originally Posted by Trevor

Thanks a lot Steve,

I have a full set of JDM RHD manuals in English and likewise call me at any time. I am in Waterview. (09) 820 8553

Thanks Trevor...much appreciated

[SVX10]

Also worth checking are the inner tie rods (the ball joint that connects the rack to the tie rod). Those wore out on my '92 @ about 150k. Tire wear symptoms were identical to yours, except not as extreme because I got annoyed by tire noise and fixed it before the tires completely wore out.

To check the inner tie rods, I jacked the front of the car up off the ground and removed the tires. Then, I would "hug" the rotor and apply torque about the steering axis. What would happen is that the rotor/knuckle assembly would turn a few degrees before engaging the rack. You have to be gentle, slow, and precise w/turning the knuckle because the slop is very small and easy to miss if you turn it too fast/forcefully. When I took the protective boot off of the inner tie rod, I could see that the ball joint had a small amount of slop allowing the tie rod and the wheel to move independent of the rack. My assumption is that the tires were being pushed to a slight toe out condition under road load conditions causing the specific inner shoulder wear.