Squealing o/side tyre

Post by **wanderinstar** » Sat Sep 23, 2006 4:45 pm

When I go to work in a morning I go round a 90deg r/h bend. When only traversing this at about 15-20 mph the fo/s tyre squeals like mad. When going round l/h corner no problem. The tyres dont help they are 155 x 13 of Polish origin. While having the last MOT the examiner asked me about the accident the car was involved in. I said, not to my knowledge. But it showed up on computer. Still haven't got to the bottom of that ,yet.
I suspect the steering geometry is out somewhere. But when I asked at local ATS they said they didnt do steering geometry checks. Any idea where I can get this done.
Ian.

Post by **nebogipfel** » Sat Sep 23, 2006 4:52 pm

Ian,

Before you worry about the previous accident and possible damage it would be well worth swapping the wheel with one of the rears or the spare to see if the squeal disappears.

It may well just be a tyre which has gone hard (or soft I suppose)

Certainly worth doing first

Post by **Alec** » Sat Sep 23, 2006 4:56 pm

Hello Ian,

I would get the tracking checked first, which your local ATS should be able to do.

Alec

Post by **bmcecosse** » Sat Sep 23, 2006 8:15 pm

Ian - I made my own tracking gauge from three bits of dexion angle. One long across the car and two short at right angles - it works. But also make sure the track rod ends are scewed on to the track rods equal amounts both sides - measure the amount of visible thread on each track rod. If the steering is 'offset' (ends not equal) then the Ackerman angles will not be correct - and so the wheel may not following a true rolling radius with the inner wheel.
Or it could be you are just going too fast!!

Post by **wanderinstar** » Sat Sep 23, 2006 8:51 pm

Too fast!!! 15-20mph.

Post by **moggyminor16** » Sat Sep 23, 2006 10:19 pm

well i had the same and i took to the local tyre place did the tracking and at lest now its back on teh scale it was wayy off not eithern registing on the gage so get it done save bthe tyres

Post by **Alec** » Sun Sep 24, 2006 8:22 am

Hello BMCE,

I'm not so sure that the Ackerman angle is affected by the way the tracking is set as the steering arm angle relative to the wheel stub is fixed at the correct angle. Unless of course the steering arm has been bent at some time.
Incorrectly set tracking gives less steering lock on one side than the other.

Alec

Post by **Willie** » Sun Sep 24, 2006 11:38 am

You could start by placing the wheels in the straight ahead position and then
checking the number of steering wheel turns to full right and left lock. If the
rack was not centralised correctly at some time you could find a considerable
difference. The subsequent tracking adjustments would compound the problem.

Post by **bmcecosse** » Sun Sep 24, 2006 3:56 pm

If the steering is offset by the track rod ends being screwed on different lengths each side - then it does affect the Ackerman - the track rod assembly on one side will be shorter than the other - no problem when straight ahead - but as more and more lock is applied it will start to have an effect and the two wheels will no longer be running on correct radius to each other. It's not a lot - and not noticeable except on tight corners (90 deg bend here we are told) - but I suspect that will be the trubble. Could also be different caster angle one side to tother - if it's more than usual then as lock is applied this pulls more negative camber on the outboard wheel - good thing for 'turn in' and cornering in general - but it does make the steering heavier - and would put the outboard tyre more on it's inner edge on a tight corner - perhaps leading to the squealing! If the caster was somehow less than normal - then the outboard wheel could be going +ve camber - putting the tyre on it's outer edge and certainly leading to squealing. Does the car run true with hands off Ian ??

Post by **bigginger** » Sun Sep 24, 2006 5:40 pm

bmcecosse wrote:Ok - it's brakes - to stop the car.

It's "does", "trouble", "general" and "t'other" too...

Post by **bmcecosse** » Sun Sep 24, 2006 5:45 pm

Oh - I think I have seen you make the odd typing error Mr G !! None of us is perfect. But thanks for the marking - I will go through it and correct where needed - and write 100 lines !!
Edit - sorted now - and I found a few more in there you had missed too. Trubble is intentional - sort of 'joke'. Ha ha.

Post by **Alec** » Sun Sep 24, 2006 6:09 pm

Hello BMCE,

I'm afraid we will have to agree to disagree on the Ackerman effect.

Alec

Post by **bmcecosse** » Sun Sep 24, 2006 6:25 pm

Ok! But it is important that the steering rack is dead central and the track rod ends each on the track rods by equal amount.

Post by **Alec** » Sun Sep 24, 2006 7:02 pm

Hello BMCE,

as I said earlier "Incorrectly set tracking gives less steering lock on one side than the other. "

Alec

Post by **bmcecosse** » Sun Sep 24, 2006 7:06 pm

As did I way back at the beginning - when I briefly mentioned my home-made tracking gauge. Actually the tracking could be completely correct - in the straight-ahead position - just the rack offset to one side which upsets the steering on lock (and I believe but you don't, upsets the Ackerman angles!!).

Post by **wanderinstar** » Sun Sep 24, 2006 8:13 pm

BMc,
Yes the car does run straight in straight ahead position. Will check track rods when I get a chance.

I thought this was a Mechanical Section, not an English Spelling Section. What next punctuation and grammar correction. It is pathetic, all this backbiting.
Ian.

Post by **bigginger** » Sun Sep 24, 2006 8:18 pm

bmcecosse wrote: Edit - sorted now - and I found a few more in there you had missed too.

How queer. They must have appeared after I read it.

Post by **Onne** » Sun Sep 24, 2006 8:19 pm

Correcting the spelling makes it a lot easier for foreigners like myself to read peoples posts Ian.

Nothing wrong with keeping the Queen's English to a good standard.

Post by **Willie** » Mon Sep 25, 2006 4:21 pm

IAN, I repeat, what are the steering wheel turns left and right from the straight ahead position?

Post by **bmcecosse** » Mon Sep 25, 2006 5:58 pm

Yes Mr G - I did go back and re-read the piece - which I had typed up quickly in a spare moment - and I found a good few more typing errors - all of which I corrected. I seem to have a habit now of sometimes typing the letters in the wrong order - a common problem with two finger typing - I notice quite a few on here doing the same thing!!