Hi all,

Recently noticed that when I'm braking that I'm getting a slight metallic knocking sound. Can feel it a bit on the floor, and maybe a bit in the brake pedal, but the knocking feeling isnot exclusive to the brake pedal, but only happens when braking. Where might I start checking? Are there any 'usual suspects'? Not driving it in the meantime, as mechanical suspension problems wig me out, particularly on such a heavy car.

I'm thinking to check out the following: Bearings, pads/calipers, tie rods, control arm links?

Would appreciate any and all suggestions on common issues or how to verify the various component. I don't have a lift, but can jack up one side at a time and can perhaps listen or try to feel for wobble.




Thanks!

Sam

 

Check the lower inner control arm bushings...the big bushings that bolt to the subframe. They slide backwards when worn-out while braking.

 

Many thanks, will check those out.

 

Digging into this, looks like a lot of things.

Wheel bearings and compromised bushings on sway bar links, all 4 upper control arms, outer lower control arms, and both outer CV boots. Have ordered hub bearings and a full control arm kit. Now contemplating whether to replace the axles or just the boots.

Anyone have a list of bolts/nuts that need replacement handy? I've got the ones (8) for the hub bearings and both front axle nuts so far, but need to order all of the ones for the various control arms and end links.

Thanks!

Sam

 

Hi Sam,

As said already the knock when braking is normally but not exclusively the inner bush on the rear lower control arm, polybush kits are available and probably preferable to the original bush as with such a fast and heavy car this item gets a lot of wear and it saves you junking a perfectly good control arm as the ball joints seldom wear. I recently replaced mine with polyurethane bushings and although i didn't have any knock on braking there was some contact witness marks evident and the original bushes were well past there best. The upper control arms can be rebushed as well if the ball joints are fine, also polybush kiks are available for the anti roll bar links as well. As long as the original cv joints weren't making any bad noises when turning on full steering lock and the boots haven't been split for any length of time I'd just fit new boots.
Regards Chris.