I had my SVA a few days ago and unfortunately it failed on some minor issues and one of the failure points was no self centering of the steering, I would like some advice regarding this issue as the car does not even slightly try to self center.

My first question is; Are the geometry settings stated in the MNR build manual correct?

Front camber 1 to 1.5 degrees of negative camber
Rear camber .5 to 1 degrees of negative camber
Front tracking 1 to 1.5mm toe out
Rear tracking 1 to 2mm toe out

I agree with the camber settings but the tracking settings seem a little strange?

Also there seems to be no caster adjustment, I have measured this and it is currently 5 degrees positive.

From previous experience I believe the way to increase self centering is to increase caster angle, but It seems this is not possible?

Any help would be much appreciated.

Its possible that you need to apply a set of SVA settings for the test then redo them so it drives OK. Thats how i had to do mine anyway - i know its not a MNR but most cars seem to follow this rule.

Temporarily increasing the front tyre pressures to 30 psi will help.

Already tried the increased tyre pressures (35psi), and it made no difference.

I was told to set my car up with the following settings

-1 to -1.5 degree's camber all round
1mm toe in all round

For sva I had no toe and 0 camber all round and passed first time.

Have you got the top wishbones on the correct way. The ball joint for the upright should be behind the bottom wishbone upright ball joint when viewed from the top making the upright itself lean backwards when assembled. Just a thought.

[Edited on 19/9/08 by stuart_g]

Which sterring rack are you useing ie,

Shortened sierra or Escort ?

Also

Sierra or Cortina Hubs ?

everything else looks ok can you post up some photo's of the front ?

regards

Agriv8

Yes the top wishbones are on the correct way round.

Its a sierra rack with sierra uprights/hubs

I currently have the front and rear tracking set at 1mm toe in all round, not as per the build manual (toe out?)

Regards,
Lee.

I tried all the tricks on my Indy and it never self centred

I cheated and put some valve springs in the rack which did the trick.

Paul

Ok then a few futher things to check.

1 that the steering shaft runs freely in the sierra body.

2 that the mushroom incerts have the hole facing towrds the front.

3 have you tried winding more spring on the read ( transfer more weight to the front )

Let us know if any of those help

Regards

Agriv8

Mushroom inserts are now facing forward

Raised rear ride height, to transfer more weight to the front.

Front camber set at 1 1/4 degrees negative
Front tracking 1mm toe in
Front caster 7 degrees positive

Still no self centering & with the geometry settings above it should self centre so I have now come the conclusion that the problem must lie within the rack as it feels a tight even when the hubs are disconnected.

I believe the rack tension can be adjusted from the slipper plug on the top of the rack, but is this a simple matter of turning it with an allen drive socket or is there more to it than that?

Regards,
Lee.

Lee,

Sound like you have found the problem. The shaft should be easy to push through with a small amount of resistance and no lateral play

I belive it should be that simple for the adjustment but I think they have a tendancy to be FT. The shaft is pushed against the nylon 'Shoes' so you need to reduce the friction between the 2.

Regards

Agriv8

Got it all sorted out now

It was the rack that was too tight, adjusted the slipper plug & hey presto got self centering. My god it was tight to undo though.

Thanks for your help guys

Regards,
Lee

Lee,

Thank gawd for that

Get the SVa finished and then book in to MNR or somwhere for a setup ( corner weights, tracking, camber ect).

Good look with the re-test

Agriv8