Mystery steering knock

[fredm1905]

I have a Marina based Roadster which is set up for Classic Trialling. On light braking there is a definite kick/knock from what feels like the off side front wheel. It stops when the brakes are more firmly applied. I can't find anything obviously loose or wobbly and replacing the shock absorbers made no difference. Any clues please?

[b_caswell]

Re: Mystery steering knock

Possibly the pads kicking up and down in the caliper, when you apply the brakes fully the pad stays against the top of the caliper.

[stevejgreen]

Re: Mystery steering knock

If you had not checked, I would start at the Tie Bar Bushes, move on to the Trunnions, but something I once found, after fitting vented discs, was fore/aft movement in the Mini upper wishbones.
I did do a write up in Pitstop but can't remember when. I will have to look it up.
IMHO there should be around 0.1mm movement maximum but I found nearer 1.0mm with 'new' parts. I could find no dimensions in Mini manuals and ended up machining the parts to suit though a temporary fix was with some shims.



You can see in this pic, with a feeler gauge in the excessive clearance.

[fredm1905]

Re: Mystery steering knock

Thanks for your advice. On closer examination we found that there was excess movement in the mini wishbone. Removing the roller bearings was nightmare without the proper tool, we ended up destroying them with a hammer and chisel. Suspension is much tighter now but there is still a slight kick which I suspect may be the brake discs.

[Tnick]

Re: Mystery steering knock

Have you checked the bolts holding the front disc to the hub? I experienced a similar knock, I found it when one of the calipers siezed and found I there was a small amount of play when trying to turn the wheel before the drag of the siezed brakes.

Best tested by jacking up the front, have an assistant press the brakes whilst you try turning each wheel backwards and forwards - any play will either be either the disc moving relative to the hub or caliper moving relative to the upright.

Regards

Nick Tinsdeall

[stevejgreen]

Re: Mystery steering knock

Probably the best single guide to rebuilding the front suspension of a Marina can be found here.

http://homepages.vodafone.co.nz/~fourwalls/suspension.htm

It does not specifically cover the brakes, but may help identify an odd clunk.