Scraping noise under compression

[tejr]

On a motorway/A-road I get a scraping sound from the rear under compression on an undulating road. I don't think the cars bottoming out, but it almost sounds like its coming from the inside of the car?

Unless its the rear wheels rubbing on the arches? The coilovers have a relatively large drop on the rear and its sitting on 18" spiders with some 255/35 rubber.

Its not a knock, just a scrape/scratchy noise.

Edited by tejr on Wednesday 25th April 19:55

[G20RG B]

Brake pads rattling in the rear calipers perhaps!! I don't know, it's only a suggestion. I had a noise for about a month and nearly stripped the bloody engine to bits only to discover the front pads were moving in the calipers causing a knocking, rubbing noise occasionally, good luck with finding the culprit!!

[itiejim]

Sounds like tyres on arches - it can happen if you have the Tuscan rears fitted rather than the fronts all round.

[grovest]

This sounds exactly like mine when I was running 18" SP12s with 265 rears. The 17" RL7s with 255 are fine so it was a marginal scuff of the tyre on arch.

[Mad Mark]

Is there any tell tale marks on the tyre on just inside the lip of the arch?
Maybe try a bit of crayon on the tyre and see if it rubs off then you will know if its the tyre or not!!

[tejr]

Tbh, it probably is the tyres. As I wrote out my post it popped into my head as the obvious answer.

Was too dark and cold to crawl around the arches last night so will check when i get home from work this evening.

Thanks guys

[scotty_d]

Anti roll bar on the inner arch? looking at mine it has scuffed there before but cant comment only done 48 miles since getting my Cerb.

[ridds]

Another one to check is the diff output flanges rubbing on the chassis.

If you mounts or bushes are overly worn then the flanges can hit the chassis tubes and rub.

[tejr]

For some reason diff was the first thing that came to mind, but I ruled that out in my head as i thought worn bushes would manifest themselves as more of a clunk and possibly also show up under acceleration which it isn't and they don't.

But next time I'm under the car I will look out for them.

Lifting the rear about 25mm has been on the cards for a while now, so that should rectify things if it turns out to be rubbing tyres.

[FUBAR]

ridds said:

flanges

I love that word

[PoleDriver]

What type of ARB drop links do you have? I've got the rose-jointed ones and they were worn and rattly. There was also a squeeky noise under compression (or when jacking the car up) this was the ARB bushes sticking to the ARB. A pair of poly bushes cured that!

[bouldster]

hi it could also be bowed springs rubbing on shocker bodies?

[gruffalo]

FUBAR said:

ridds said:

flanges

I love that word

Well you would


So do I.