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SVA RETEST FAIL AT BRISTOL
stupott901 - 14/8/09 at 10:53 AM

Hi there

Just had retest at Bristol all going well untill it came to self centering which it failed

and then Howard noticed that the front wheels were rubbing on the suspension arm ahhhhhhh

Then Howard tried to adjust the tie rods and as he was turning the tie rod it fell out the the rack and then he said there should some sort of locking device to stop it from coming out but i looked in the the sierra manual and there is no mention of any sort of locking device

so i have two questions

1 how do i make it self centre
i have tried a bit of toe out and put 36 psi in the tyres

2. is Howard right about there being a locking device where the tie rods screw into the rack?


thanks for any help
stu


Mr Whippy - 14/8/09 at 10:58 AM

dude it sounds like you were very lucky that the arm fell out when doing a test rather than on the road. There's a roll pin that locks the screw cap on so it can't unwind


02GF74 - 14/8/09 at 10:58 AM

quote:
Originally posted by stupott901

Then Howard tried to adjust the tie rods and as he was turning the tie rod it fell out the the rack


Lucky you - Howard may have saved your life - imagine that happening at 70 mph on a busy motorway!!

Who said SVA were a bad thing?


tegwin - 14/8/09 at 11:11 AM

Im amazed that Howard spotted that... sharp edges are far more important!


Bluemoon - 14/8/09 at 11:33 AM

^^^ dito that's whats sooo soo silly about the who SVA/IVA thing.. But it's better than an MOT in this respect; my tester was very good and tested more than an MOT ever could (expect things like tire condition ect... bit daft but hay ho!).. He really wanted to make sure it was safe!

Good luck with getting though the next test!

As to the self centering might be an idea to look at getting some wishbones by the guy on here that will fix the selfcentering.. (can't remember the user id someone will be along to tell you who!)..

The thing is you need to get on with the retest and get it to pass else your 6-months will be up (and then it's the IVA +450 quid!....)... So rather than mess about I'd change the upper wishbone...

Mine passed the self center test with ~18psi in the front tires.. No silly tow settings needed. This was with standard MK parts..

Dan



[Edited on 14/8/09 by Bluemoon]


RickRick - 14/8/09 at 11:50 AM

i found much lower tire pressures made mine center better, went from 30 down to about 10


MautoK - 14/8/09 at 11:56 AM

Make sure that your rack is not binding or tight. I think you should be able to work it lock-to-lock by push-pull on TRE with not too much effort.
I was OK (just!) with standard MK setup and around 26 psi.
John.


paulmw - 14/8/09 at 11:59 AM

Put some valve springs in the steering rack.

It worked for me and lots of others on here


David Jenkins - 14/8/09 at 12:12 PM

Before bodging a fix, make sure that what you've got is working properly!

Disconnect the steering down-link and waggle the steering wheel around - is it moving freely, without resistance?

Now jack up the front of the car and try pushing the wheels from side to side - you should be able to go from lock to lock without much effort at all (there will be a little resistance, but not much).

If either (or both!) of these are stiff to move then any natural tendency to self-centre will be cancelled out.

If they are free and easy, consider finding some way to move the top pivot back a little on each side to correct the geometry.

Don't faff around with quick fixes - proper self-centering is a good thing, and makes the car much more pleasant to drive.

Also, the testers are wise to most of the tricks, and they may get pee'd off if they spot anything that isn't kosher.


wilkingj - 14/8/09 at 12:14 PM

Make sure the top wishbones are located as far back to the rear of the car as they can be (space with large washers), and the lower wishbones are as far forward as you can get them. This will give you the maximum Castor angle that you can get without changing the bones for different ones. This should assist with the self centering.
Its worth a try.

Jack both front wheels off the ground, and test the steering from lock to lock to see if there are any tight spots.

Also remember the SVA is about making sure the car meets the design / build specifications for cars that are allowed on the UK Roads.
ie sharp edges etc on your Mondeo's are removed in the design office at Fords.

We do not have the luxury of a multi million dollar design office!
So the SVA / IVA is there to make sure it meets the legislation for cars, as well as being basically safe.

Whereas the MoT is there to ensure the car is safe for the roads, as it already meets the design / build legislation. ie it was designed and built to meet that spec by the manufacturer.

SVA / IVA has a different role to play as compared to a MoT, although there will be cross-overs between them.

Simples... chk!


stupott901 - 14/8/09 at 12:15 PM

yes im glad howard noticed the steering rack problem that would of been nasty im glad i trailored it there now i was going to drive

i have got it booked in for an retest in 2 weeks time so need to get sorted really

anyone know whoe the guy is who does the modified whishbones ???

the rack is not tight or binding

Pualmw you said put valve springs in the rack where do you get the springs from and how do you fit and what wil that cure i know most probably stupid question ?

cheers guys for your input


Madinventions - 14/8/09 at 01:45 PM

A sure fire way to get self centering is to remove the gaitors from the steering arm and put a short bit of split rubber hose over each end stop on the steering rack. Hold this on with a jubilee clip for now (some people have suggested using just a jubilee clip to limit steering lock...) This way, when you're on full lock the rubber hose is slightly compressed so when the SVA/IVA man lets go of the wheel from full lock, it springs back just a tiny bit and voila - ' a degree of self centering' is achieved.
Then you can set up your front wheels with correct toe in and correct pressures which makes it much safer to drive to the test.

Trust me - it works, but I admit that it is a total bodge and I'm sure I'll get flamed for suggesting this. I had to reduce the amount of steering lock on mine for SVA and used this method and got a first time pass! Needless to say, it all magically fell off shortly after getting the MAC certificate.

Ed.


Madinventions - 14/8/09 at 01:51 PM

Just to add... After a few hundred miles, my steering rack is now nice and free with no tight spots and I have good self centering without any bodges. Also, an inch or so of rubber hose won't rattle like a valve spring might...?

Ed.


james h - 14/8/09 at 02:12 PM

quote:
Originally posted by stupott901

anyone know whoe the guy is who does the modified whishbones ???




wozsher (or some variant of that)

James

p.s. mine had better self centre next wednesday!


Mark G - 14/8/09 at 05:44 PM

Sorry to hear the car failed. you can limit full lock by putting a blob of weld on the rack at the point where it goes into the housing.

To fix my self centering I had to remove my rack. strip it remove everything rebuild and adjust the preload on the pinion. from no self centering it now works like a dream and drives lovely.