Need Help w/ Front Tire Wear. Causes? Suggestions? (pics) (1 Viewer)

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I have a bad problem wearing out the outsides of my front tires on my '75 FJ40. When I first bought it a couple years ago, the tires had hardly any tread wear. The tires were older and a little weathered, looking like someone put tires on it and left it sitting for awhile, but the tread depth was 90% or better and evenly worn. After driving it for a couple years they look like this picture below. I can really feel and hear it when making low speed turns (in a parking lot, etc). The tires really bark and chirp when making these turns and it almost feels like there is a locker in the front diff and it's in 4wd, but it's not locked and not in 4wd. The truck has always driven straight, doesn't wander at high speeds, and there doesn't seem to be a lot of play in the steering. I was in an accident a few months ago (girl pulled out in front of me) and had the frame and alignment checked out at a shop afterwards. Frame is straight, and they said the alignment was pretty darn close to spot on. I did just install a 4" sua lift w/ new shocks. The old ones were completely shot. I also have a new tie rod end kit and a new steering stabilizer that has yet to be installed. I know this will help with a little of the steering play, but I don't think that will help with the tire wear... It's hard to tell from the head on pic, but it sometimes looks to me like the camber is out of whack (tops of tires appear to be leaned out a little). From everything I've read, this is not adjustable. Only caster and toe. I put a different set of tires and wheels on after the lift and don't really want to wear them out the same way. Any help would be appreciated. Thanks.

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Looks like too much toe in.

But those are also quite worn out...

Drive forward 20' on flat ground, put a push pin in the tread of both front tires at hub height. Measure between them, drive forward till they're at hub height in the front. The front should be about 1/16"-1/8" closer together... That'll give you an idea of what's going on with your toe in. A search should give you the exact spec, but if you find it's 1/4"+, you'll know why they're wearing.
 
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Drive forward 20' on flat ground, put a push pin in the tread of both front tires at hub height. Measure between them, drive forward till they're at hub height in the front. The front should be about 1/16"-1/8" closer together... That'll give you an idea of what's going on with your toe in. A search should give you the exact spec, but if you find it's 1/4"+, you'll know why they're wearing.

Do you put the push pins in the center of the tires? Inside, outside, or does it matter? The tie rod is bent a little bit (been like that since I bought it) which you can kinda see on the driver's side in the picture. I should try this trick before I put the new tre kit on so I know where I'm at. Was gonna try and straighten out the tie rod as well while I'm at it and then take it to an alignment shop. Should I tell them what to set the toe at or would they know to toe in a little bit?
 
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Is your tie rod bent on the left end? It could cause excess toe in... Or just be a camera distortion.

Yeah, it's bent a little on the driver's side. I ordered a new one from Rock Auto, then got a message that it was on back order and got a refund. Figured I'd just try to straighten mine out as best as possible.
 
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Don't waste your money buying a new tie rod. I would straighten the old one in a press and then roll it along something flat until it's 99% square and your happy. I love the pin idea bikersmurf will keep that in the brain matter
 
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Don't waste your money buying a new tie rod. I would straighten the old one in a press and then roll it along something flat until it's 99% square and your happy. I love the pin idea bikersmurf will keep that in the brain matter

I figured I would try to just straighten it best as possible. Didn't know how hard it would be to straighten out or how much I can bend and hammer on it and not hurt it's integrity. Rock Auto has another one from AC Delco available for $65. The other one that was out of stock was a Raysbestos one. Didn't know if I should save the money or just buy a new one and know it's dead straight. Probably save some time getting the old ends out too...
 
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Its needs to be pressed to get it straight don't even try using a hammer on it. In the bush I would take it off and hold one end and gentley smack it on a log where the bend is eyeing it straight. $65 bucks is cheap for a new tie rod.
 
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If the bent tie rod has always been bent that is probably not causing the tire wear. I suspect it is the 4 inch lift. Did you shim the differential when you installed the springs? With 4 inches you are going to need to either shim it or cut and turn your knuckles.
 
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Usually when they do an alignment, they give you a printout.
The camber looks way out to me and that will cause the kind of wear you are seeing.

Shawn, I think he said that he did the lift after the bad tire wear, if I'm reading it right.
 
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If the bent tie rod has always been bent that is probably not causing the tire wear. I suspect it is the 4 inch lift. Did you shim the differential when you installed the springs? With 4 inches you are going to need to either shim it or cut and turn your knuckles.

I just put the lift on 2 weeks ago, and this has been wearing like this for 2 years. I did a lot of research before I did the lift and from what I've found the only reason to do a cut and turn is with a spring over lift because of the extreme pinion angle which is corrected by welding the perches at a better angle which would then throw off the caster. Knuckles must then be cut and turned to correct the steering geometry. The only reason to shim it with a SUA lift is if you've added longer shackles which would push the front of the axle down causing incorrect caster angle. Since I kept the stock shackle length and the stock spring perch locations, then there should be no change in the caster angle. I've gone over and over this in my head and it makes total sense to me and still drives great after the lift. Someone correct me if I'm wrong...

Usually when they do an alignment, they give you a printout.
The camber looks way out to me and that will cause the kind of wear you are seeing.

This is what I thought too, but from all the research I've done there isn't any adjustment in the camber on a solid axle. I even asked a friend that works at an alignment shop and he said you can't really adjust the camber, only the caster and toe in or out. I thought possibly bad wheel bearings were letting the tires lean out and wear like that, but I can jack the wheel up and there doesn't seem to be any play in the bearings. Seems tight. ????

What's your time worth? I'd replace it and know it's done right. Nice truck.

Thanks, but it looks prettier from the front than the back! I've cleaned up the front and did a rattle can paint job on it. Still have some rust repair and sheet metal replacement to get to on the back half...


Actually took the tires and wheels off my Tacoma. I went back to the stock rims when I bought new tires for it and went down a tire size to try to improve the gas mileage a little. Don't really care about gas mileage on the LC.
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My point is you need to measure the camber. If it's out (it looks it) and you know how much, then you know what the problem is and what it would take to fix it. If you don't measure it because "it can't be adjusted" then you're doomed to living with it.
If the camber is the problem then there may be ways to deal with it. If the axle shaft is bent, then that can be replaced.
There are a few other ways people have reported on Pirate to do some minor adjustments.
http://www.pirate4x4.com/forum/newb...ion/1070332-solid-axle-camber-adjustment.html

If you find out that the camber is correct, then you can move on to looking at other things.

Oh, and you're right. Your truck does look better from the front. :D
 
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from all the research I've done there isn't any adjustment in the camber on a solid axle. I even asked a friend that works at an alignment shop and he said you can't really adjust the camber, only the caster and toe in or out. I thought possibly bad wheel bearings were letting the tires lean out and wear like that, but I can jack the wheel up and there doesn't seem to be any play in the bearings. Seems tight. ????

Yea, your alignment guy can't do anything about it. The bearings would have to be trashed more than I've seen to cause that kind of wear.

My point is you need to measure the camber. If it's out (it looks it) and you know how much, then you know what the problem is and what it would take to fix it. If you don't measure it because "it can't be adjusted" then you're doomed to living with it. If the camber is the problem then there may be ways to deal with it. If the axle shaft is bent, then that can be replaced.

True. If the axle is bent it will cause bad camber that could be measured. The axle tube (not shaft) could be repaired with a big press. It's unlikely the shaft on the inside is bent. There's plenty of room in there for it to move around even if the tube was bent.
 
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I thought about the axle housing being bent, but I don't know if you can tell just by looking at it. Looks straight to me. I did just find this link of someone with a similar problem. https://forum.ih8mud.com/threads/positive-camber-correction-q.239461/
His camber looks REALLY bad and said he adjusted the toe and it looks way better. The before and after pics show a big difference. I think I'm gonna start with installing the new tie rod end kit, straightening the tie rod, and taking it to the alignment shop. Hopefully that will help, if not I might have to look into a new axle housing. I've been looking for an excuse to switch to a disc brake front axle anyways! :D

I changed my avatar pic since you said it looks better from the front edwjmcgrath
 
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With stock bearings it's not adjustable... But I've been told there are offset bearings available. The alignment shop said that they're a pain, and expensive to install... They said unless its impacting the drive ability, don't waste your money, it won't significantly affect tire wear.

Since it's "not adjustable", it'd likely be cheaper and easier to swap in a new housing than have it fixed.
 

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