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sva failure


speedy jon

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hi, i had my sva yesturday and i only failed on self centering which was annoying because the sva guy was very happy with everything else. is there a few things i can try/ adjust for the wheel to self center?

i phoned w/f and they said adjust the toe in a bit more but this didnt work.

anyone got any advice?? :down:

thanks Jon

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Hi Jon,

I have my SVA on Saturday, and have been told to reduce your tyre pressure down to about 14 psi this will help greatly, becaue the tyre walls will push the car in the right direction hope this helps, try it on your local car park, thats what i will be doing tomorrow night lol

Craig

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thanks craig, will try that tonight too. remember when trying to see if the wheel self centers, keep the car at a fixed speed over 10mph and dont accel because the wheel will self center but doesnt count. also the wheel only has to show signs of self centering.

thanks fot the advice   :D

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Jon,

I had the same prob last year, I fixed it by toeing in the tracking as far as it would go (approx1&1/2 turns) and puting more neg camber on the front (about 1deg - 2 turns) and lowering the tyre pressures to about 18psi.

It was not prefect (due to all being very new & very little miles) but the wheel did show signs of sort of self centering. The SVA man passed it.

Needless to say I marked both tracking & Camber units up before adjusting them with a paint marker & loging the movement, onced 'SVAed' it was a easy job to return them to my origonal set-up.

Good Luck,

Gray

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lowering the tyre pressures to about 18psi.

:0

Thats my normal tyre pressure (cold); I was advised to drop the fronts to around 6 - 8 psi, (don't drive there with them like that though!;) I passed with the comment that I had the strongest self centreing that the tester had felt in a Westfield.

In hindsight, could have got away with a bit more pressure. And don't make the classic mistake I did, of dropping your indicators below the minimum height when you let the air out of the tyres. doh  :durr:

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Bad luck Speedy.

Self centring is affected by all changes in suspension but mostly by castor angle.  Now you can't really change this as the wishbone design is fixed but....

I have a friend who is a Dax owner.  He failed on self centring and it was due to stiffness in the ball joints.  He replaced them with some that gave more movement.  I think you should check them out.  I don't know if it is possible to effectively lubricate them but it should be.

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I had mine at 3bar(!42psi!;) during the test and she still passed, so eighter mark williams at shrewsbutry isn't that strict on it or pressure doesn't do that much.

(3bar is what was in the tyres when I got them from westfield, I didn't go to a fueling station to check it before SVA)

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hi, i had my sva yesturday and i only failed on self centering which was annoying because the sva guy was very happy with everything else. is there a few things i can try/ adjust for the wheel to self center?

i phoned w/f and they said adjust the toe in a bit more but this didnt work.

anyone got any advice?? :down:

thanks Jon

Hi,

Is yours an SDV with Sierra front upright? Toe in works with most uprights but Toe out will work on certain others including Sierra. It is to do with where the pivot point sits relative to the centre of the wheel. If toe in didn't work, toe out will. You can test it by seeing if the car will self centre in reverse.

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It is to do with where the pivot point sits relative to the centre of the wheel.

isn't that castor angle? :p

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It is to do with where the pivot point sits relative to the centre of the wheel.

isn't that castor angle? :p

Yar! but he might not know that.  :arse:  :)

Anyway, my reply was much clearer  :arse:  :D

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It is to do with where the pivot point sits relative to the centre of the wheel.

isn't that castor angle? <!--emo&:p

Yar! but he might not know that.  :arse:  :)

Anyway, my reply was much clearer  :arse:  :D

yeh i know what castor is.  :D

i got the re test on thurs and ill let you know the out come. :D

thanks for all the help.

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