Inside rim of tyre wearing too quick...?

[Jake Casson]

I have a 92 535is running on 235, 40, 18s which I know is less than idea but it looks great. Problem is the inside of one of the rear tyres has worn very quick and needs replacing, therefore both have to be replaced to keep it balanced. Any ideas why its worn so quick, a bush or something? Cheers

[genphreak]

..Problem is the inside of one of the rear tyres has worn very quick and needs replacing, any ideas why its worn so quick, a bush or something? CheersHave you been sticking your foot on the wheel when trying to stop the car? If this is wearing the rim down, try fixing your brakes... you don't ahve to open the door OR stick your foot on a rim!

Seriosuly; just get a wheel alignment and check the measurements. The guy that does it will be able to show you what is wrong if anything is...

[Jake Casson]

Had all the wheel alignments done, the bloke did mention something about it but cant remember what he said as was over a year ago. So the tracking is all fine.

[ThoreauHD]

The rears should be worn evenly on the inside of the tire. It is pidgeon-toed(/ /-----\ \) a bit so that you have full contact with the pavement when pulling high gravity turns. Since yours are not worn evenly on the inside, you should have a BMW mechanic check the camber/alignment. And you define quickly as 1 year? Or is that a bad assumption.

Can't really align the rear, as I've been told. But you can adjust it. Hell if I know the difference. I'm not a mechanic, so take what I say with a grain of dirt. Differential semantics to me. Anywho, to sum up. See a BMW certified mechanic shop and see why only one side is worn so it don't happen again.

They have a few mechanics on this board, so I suggest you wait for their judgement before forming a hypothesis.

[Robin-535im]

Can't really align the rear, as I've been told.

Generally the rear shouldn't need alignment unless parts are bent so the fix may be to get new suspension parts... They do sell off-center trailing arm bushings to tweak things but like Henry David, I don't know how they measure/apply these to fix it.

[joshua43214]

E34's are built with negative camer in the rears. Camber is the angle of the wheel measured verticaly through the hub as it relates to the top and bottom of the wheel. Or in other words. when the top of the tire is farther inward than the bottom of the wheel, you have negative camber.

On cornering the G forces combined with body roll will force the wheels to tilt outwards. Negative camber, makes the wheels tilt into vertical, providing more tire contact area.

It is normal for the inner tread to wear a bit faster than the outer tread. when driving the tire will compress more on the inner tread allowing contact with the outer tread. When you do anything to stiffen the sidewall, you accelerate inner tread wear, bigger rims, over inflation, using runflats or high performance tires will cause more uneven wear.

Also, camber is ride height dependant, when you lower the body, you increase negative camber, increaseing tire wear.

Worn control arm bushings will also increase negative camber, as will saggy spings.

If you have one side that is wearing noticably faster than the other, either you are only turning in one direction all the time, or something is worn out. Uneven tire wear will not have to come from camber, but can come from incorrect toe as well. Normaly this will be noticeable as a tracking problem unless the front was aligned to compensate.

The pic of your car looks like it has been lowered. It possible that the problem is the combination of parts you are using, or something is worn. I would crawl under there and look for anything worn out, but it would be really cool if you could dig up the aligement sheet from when the job was done so we can see the numbers.

[632 Regal]

check your dogbones, and the trailing arm bushings. Look for a bent trailing arm too. The rears do wear more on the insides but both should wear evenly.

[Jake Casson]

Right, I have the numbers here after the alignment by a top UK performance centre on the best machines.

Final readings,

Caster 7 44' on left and 8 13' on right

Camber -0 16' and -0 20'

The can is a sport model so is 30mm lower as standard and runs on BMW parts.

I did crash it a few years ago so this could be something to do with that, was all jiged out and parts replaced as needed. Many thanks

[Alexlind123]

My brother has an e28 on which he discovered the caster (toe) to be out. He fitted adjustable camber/toe plates to correct the problem.

[joshua43214]

Caster petains to the front wheels. It is the realationship between the upper and lower pivots. Or how far forward/rearward the upper pivot point is compared to the lower pivot point. Its primary purpose is to cause the wheels to return the straight ahead position. It also affects handling on cornering.

The print out should have provided rear camber and toe. front camber, caster, and toe.

Do you have the rear wheels numbers?

[joshua43214]

My brother has an e28 on which he discovered the caster (toe) to be out. He fitted adjustable camber/toe plates to correct the problem.

Caster is not toe. All caster does is move the top of the wheel forward or rearward, In theory, this will have no affect on toe at all, since no part of the wheel is being move inward or outward.

Camber directly effects toe since as you move any part of the wheel outward, the tie rod will prevent its side of the wheel from moving outward as well,causing it to toe in the opposite direction.

[Jake Casson]

The rear wheel number are in my last post, forgot to put the toe which on the rears is 0 00' left and 0 08' right.

Go I am confused now, dont really understand the print outs and which is the before and after. One says a total toe of 0 08' the other 0 16'.

The car is in for a MOT tomorrow so will tell them about this to see if he knows.

[Alexlind123]

Caster is not toe. All caster does is move the top of the wheel forward or rearward, In theory, this will have no affect on toe at all, since no part of the wheel is being move inward or outward.

Camber directly effects toe since as you move any part of the wheel outward, the tie rod will prevent its side of the wheel from moving outward as well,causing it to toe in the opposite direction.

I wasnt very specific. I was talking about the rear wheels and toe.

[Jon K]

Guys - more importantly... does he have an open diff? If so, that will cause one tire to wear more than the other ;)

[BillionPa]

HOLY CRAP did you say 8 degrees negative camber????

thats is WAY too much, the mtech suspension is just under 3 degrees.

anymore than 5 and your tires are owned.

[Robin-535im]

HOLY CRAP did you say 8 degrees negative camber????

thats is WAY too much, the mtech suspension is just under 3 degrees.

anymore than 5 and your tires are owned.

Remember though, an English (metric) degree is different from the ones we use. You have to multiply by pi/lambda to convert.

[genphreak]

Right, I have the numbers here after the alignment by a top UK performance centre on the best machines.

Final readings,

Caster 7 44' on left and 8 13' on right

Camber -0 16' and -0 20'

The can is a sport model so is 30mm lower as standard and runs on BMW parts.

I did crash it a few years ago so this could be something to do with that, was all jiged out and parts replaced as needed. Many thanksYour numbers are way out. Needed to have been fixed back then- wear is to be expected running like this. If that low from factory the car would already have non-concentric bushings and the rear wheel settings will measure differently to standard suspension e34s. This would be the case if you have real M-technik suspension or an actual M-car. Beware, 'sport' suspension (much more common) would not have them (but I might be wrong). There are therefore 3 sets of rear aligning measures applicable to an e34, stock, sport and M-technik. Beware though, as fitting and replacing non-concentric bushings is a specialised job for a pro who knows how.

Your rear wheels will always be out of alighment if you have 30mm lowered suspension and standard bushings. This results in accelerated tyre wear on the inside of each rear tyre. Just swap the tyres around on the rims 1/2 way through their life but most people live happily with this.

The reason for your poor wear is definately the crash unles something has failed on one side only. As Joshua said, check all components for damage/wear/faulty operation. If your 'crash' impacted either rear wheel it could just be a bent trailing arm. However this would have been fixed (so perhaps done already) by any half decent repairer- this is well understood by most smash-repairers as most cars have similar problems and all BMW rear ends are designed to bend the trailing arm before anything else. Easy fix if they did not reaplce the arm, but depending on the damage adn what they did do to repair it, it may be something worse...

Remember, the only way you can adjust the rear suspension is; confirm all parts are working to specification and then fit non-concentric bushes OR change ride-height (ie by changing springs or fabricating spring spacers). Making physical adjustments (ie bending the structural parts themselves) is not just inadvisable, it is probably impractical or risky and/or illegal. There are no adjustments you can make to the rear suspension any other way- and the front suspension only has toe adjustments (ie by turning the tie rods).

I know it is hard to believe but it is one of the simplest cars on the road alignment -wise.

[632 Regal]

only in your particular combination, wheres my ride?

Guys - more importantly... does he have an open diff? If so, that will cause one tire to wear more than the other ;)

[BillionPa]

say what!?

[Jon K]

only in your particular combination, wheres my ride?


LOL - my friend wyn bought style 5's off some E39 car, one tire was worn thru the rest were great

[Jake Casson]

Yeah here in sunny england, its prob different. It has a LSD being a sport. Off for MOT in an hour.

[Nick.Hay]

My 535i does it too.

Has you car been lowered?? It may need camber correction in the rear.

Since my car was lowered and the 18s fitted, it kills them in about 50,000 km. Still not bad, but its all inner wear.

This is because the lowering springs affected the camber int the back. They make a kit to rectify it.

[Jake Casson]

Its 30 mm lower as its a standard sport model which has full m-tec kit. Had MOT now and failed on the tyre and front wheel bearing. Getting them to look into this prob as just forked out on 2 new Goodyear F1s, managed to get them at nearly trade through a friend - 103 UK pounds each - now that good.

[joshua43214]

lol, I had assumed the numbers posted where faulty since they had a caster figure and it was so far off. I was going to ask you to scan the print out and post it. Maybe you can do that with the new alignment sheet? would be cool to see the all the numbers.

[ThoreauHD]

This has been a very intructive thread.

[Jake Casson]

What do you mean ThoreauHD?

[Rigmaster]

Did the alignment spec sheet include any mention of rear TOE???

In my experience, it's TOE that will eat up the inside of a tire much more than camber. Negative camber WILL wear out the inside of a tire, but too much toe will eat them up in no time.



Bret.

[jjw]

You will have to be having toe-out to wear out the inner tires. In this case, it is too much camber and not enough toe-in. With the right combanation of toe and camber, the tires will wear evenly, but sometimes at a faster rate.