Scraping sounds when reversing?

[Pablito]

Calling all surfy gurus...

Today when I engaged reverse gear I heard what sounds like a tinny scraping noise... The car engages all gears fine and seems ok but when I engage reverse and start moving you can hear the scraping sound. It is not very loud but it is definitely there.

Like I said, it is a tinny scraping noise... Almost sons as if something like a heat shield was dragging on the floor. I obviously checked underneath and nothing is hanging off.

No dodgy noise when moving in any other gears...

So... Anyone know what it might be?

Thanks in advance.

Pabs

[shokenore]

Might be worth checking all the exhaust hangers.
Is it rev related ?

[Pablito]

Yeah.. I think it is rev related in so far as it becomes more pronounced as you increase the reverse speed... however it is not deafening or anything

I drove about 300k this weekend without it missing a beat.. and again today i drove another 40k or so without any issues at all. All gears engage, L, 2 and D and reverse... it's just the noise is there as you move in reverse.

The sound seems to be coming from left of the drivers position, kind of mid to front of car...

[BUSHWHACKER]

Propshaft U/J?

[Pablito]

Sorry mate.. can you educate me please.. What is a propshaft U/J?

I spoke to friend of mine and he did mention that it may be some thing fouling on propshaft or axle or something that is not on the way when spinning one way, but is when spinning in reverse?

[BUSHWHACKER]

Sorry mate.. can you educate me please.. What is a propshaft U/J?

I spoke to friend of mine and he did mention that it may be some thing fouling on propshaft or axle or something that is not on the way when spinning one way, but is when spinning in reverse?

These........
http://www.roughtrax4x4.com/?doc=16&cid=148&vid=192

There's one at each end of the rear propshaft. It's usually the U/J at the diff end that wears out first causing the noise you describe, but you may as well replace both whilst it's off.

[shokenore]

I did have a bit of flint that got trapped between the front disk and the backing plate.
It would make a weird sort of screeching and sometimes a bit like a rattle can of spray tingling noise occasionally, but only in reverse.

[Pablito]

The noise is definitely metallic.. it sounds like a thin light piece of metal (like an aerial or something) being dragged over rough concrete... the faster i move in reverse, the louder the sound gets.. but not deafening or anything.

If i had to give location of noise, i would say that it is under passenger foot well.

I have done a load of searches on here and it seems that many have had a whining or screeching noise and it is the universal joints that need replacing.. but this is not whiny or screechy.. it is as described...

Any other ideas or am i best to just swap the UJ's anyway to eliminate it?

If so.. how hard a job? Can a muppet like me with the help of a friend do it? Or does it need a garage touch?

[shokenore]

It could possibly be the brake pad wear indicator.
It is a thin metal pointer on the brake pads.When the pads wear down the pointer comes into contact with the disk.
It could be this.
It is a quite distinctive noise.
Might be worth seeing if the noise goes away or changes with slight brake pedal pressure whilst moving.

Or pulling a wheel off and checking visually for pad thickness.

[Pablito]

Well... Update:

Pads are nice and fat so not going to be the worn pad indicator I don't think.

Checking the passenger side wheels it seems that there is nothing fouling or catching axle or hubs (well I'll take the wheels off when I get the sodding locking wheel nut key which is in the post)

When in reverse, if I just move under idle power the noise is either barely audible or not there at all... The faster I move in reverse the more pronounced the noise seems to be.... However definitely seems quieter today than yesterday... So maybe it is something stuck in a dodgy place...

Anyway... Might well be worth swapping the UJs since they are fault cheap and looking under the car today it doesn't look like it would be a major job at all.

[andyverran]

Passengers front foorwell?

I think my next move would be looking for shokenore's flint in the brake back plate....when the nut arrives of course

[Pablito]

I think you guys are right.. I got under the car this evening as the sound was worse again today.. I had a poke around and removed absolutely shedloads of mud and stones that was just sitting in the sump guard bash plate.. and I mean shed loads.. i have a pic on my phone but left my cable at work so cant upload till tomorrow but will post it later.

i removed a load of grass and bits sticking out from all over... and started poking around the back plate of the brake discs.. which had a bit of grass and bits poking out.... and the sound of me running my nails or a screwdriver etc along the back plate is exactly the same as the metallic scraping sound when i reverse... This has encouraged me lots...

All i need now is for that sodding locking wheel nut key to turn up so I can actually get the wheels off...

[shokenore]

Don't machine Mart do a locking wheel nut kit ?

[andyverran]

Don't machine Mart do a locking wheel nut kit ?

Yep...

[s car go]

I Can't see how mud and stones built up will only cause noise in reverse.

I'm with Vince on this one, You're looking for something where the stress changes when the driveline is altered IE the UJ's.

Regards

Mark