Compliance bush

[jonbarrett]

Still trying to solve my never ending brake judder. Replacing one component at a time till I find it. I've arrived at the compliance bush at the front of the drag arm on the lower front suspension. The rubber portion of this bush seems to extend out of the rear of the drag arm. I assume that under braking this compresses, causing the whole sustemsion assembly to move backwards slightly. I can force this to happen by putting a crowbar between the drag bar and chassis and levering it back and forth.

Firstly, why is it designed to work this way. I would have thought any longitudinal movement of the suspension would be a dab thing.

What would happen it I cut this rubber away and packed the joint to prevent movement.

[TT Tim]

jonbarrett said:

Still trying to solve my never ending brake judder. Replacing one component at a time till I find it. I've arrived at the compliance bush at the front of the drag arm on the lower front suspension. The rubber portion of this bush seems to extend out of the rear of the drag arm. I assume that under braking this compresses, causing the whole sustemsion assembly to move backwards slightly. I can force this to happen by putting a crowbar between the drag bar and chassis and levering it back and forth.

Firstly, why is it designed to work this way. I would have thought any longitudinal movement of the suspension would be a dab thing.

What would happen it I cut this rubber away and packed the joint to prevent movement.

Jon,

Have you replaced the bushes with Poly ones?

I would suggest that, if you haven't, try this first.

Good luck

Tim

[jonbarrett]

I will try this.

I've not see a Polybush close up, are they compliant like rubber or stiffer like plastic?

[Toadusmodus]

I had brake judder on my Cerb, took ages to sort it. Eventually tried changing the very bush you mention, and voila, no more brake judder. Powerflex poly bush kit for the front.

[jonbarrett]

Thanks chaps, polybushes next week. Fingers crossed.

[shpub]

jonbarrett said:

I will try this.

I've not see a Polybush close up, are they compliant like rubber or stiffer like plastic?

They are polyurethane which is a cross between the two. They are a bit stiffer but still complient but not as susceptible as the rubber versions to heat and wear.

For piccies look here...