GT6 MK3 - banging and rattling

[Dave pb]

Hi there

 

I've noticed quite a lot of noise coming from the back end when driving over bumps and even small undulations.  I've had everything out of the boot in case it was that, but no, still happened.  So now I'm thinking dampers or spring or maybe radius arms.

 

Are there any basic checks I can do to narrow down the search?

 

Cheers

Dave

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[Paul H]

Hi Dave I had the same on my Vitesse Mk2 , and only found the cause when I upgraded to vertical shockers. The rear end was floating over the out riggers as there were no bolts in the boot connected to the out riggers - Im sure your noise isnt this as its progressive 

 

Regards

Paul 

[dougbgt6]

Exhaust come adrift and slapping on the underside? Easy to check. Baffles in the rear box come adrift, not so easy to check. I've had a broken rear spring, it didn't contribute any noise, didn't notice until I eyeballed it while doing the rear brakes. Could be UJs, there'll be play in the wheel, if it is. Could be prop shaft UJs, again there'll be play.

[Pete Lewis]

check all the body mounting bolts especially on the diff crossmember 

[JohnD]

Dave,

get under the rear end - ON AXLE STANDS - with a long screwdriver, pry bar or similar.

Have a go at levering on all the suspension links, bushes etc.

Something is loose/worn and needs resetting or replacement.

 

Anything else is guesswork.

John

[Clive]

Agree with John (especially the correctly supporting the car, I have taken to putting the wheels stacked under the car too when possible)

 

However, it is not easy as there is so much tension in the setup, so don't expect it to feel loose, you are looking for movement, often surprisingly small.

My guess is shocks. Have a good look at the top mounts, should be a bracket and plate on the wheel arch if rotoflex. They were always a place for rust to breed. Otherwise shock bushes. If replacing I strongly suggest polybush. Check the actual shocks too, easiest by undoing one end.

radius arms can cause one heck of a racket, especially if blipping the throttle when moving along, the jerking makes it seem the car is falling apart if bushes/bolts/mounts are iffy

[Dave pb]

Thanks all.

 

Car up over the next few days, and will have a good poke around.

Cheers

Dave

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[daverclasper]

I had this. It got progressively worse. It was play in a front radius arm bush.

 

Dave 

[Gully]

If you still have the rear shocks attached to the inner wheel arch, even the smallest amount of play in the top bush sounds horrendous. Also worth checking how well adjusted the tailgate is - if it's sitting on the latch and floating away from the seal then that rattles too.

 

Gully

[Dave pb]

Hi.

 

A had a root around underneath - looks like the bush on the offside body-fixing radius arm  has passed its best - I can lever it left to right along the bolt and back again. This does not seem normal, does it?

 

Also I did have a rattling tailgate - I fitted a new seal recently - needs testing properly.

 

Cheers

Dave

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[daverclasper]

That's the one that caused my noise. Good luck

[JohnD]

A gone bush can be levered at right angles to its bolt - well, it's supposed to do that, but excessively.

Which end of the radius arm?    The bush should be a snug fit in the bracket, no slop as you indicate.

 

John

[Dave pb]

Its the body end. Not the wheel end.

 

Dave

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[Dave pb]

Well, I changed the radius arm bushes for some new poly things. One of the large bushes was sliding left to right along its metal inner. When I took it off the inner metal tube just fell out. The other one was still intact.

 

Anyway, after a long struggle getting the - what looked like original - metalastic large bushes out (with chisel, hammer, sockets etc), and just pushing the small bushes out with sockets in a vice, the new ones are in, the radius arms are painted,  and all put back together.

A test run of about 5 miles tonight showed a distinct improvement.  Of course now I can hear all sorts of other rattles and bangs.  And the clutch needs changing.  At least the radius bushes were correctly identified as one problem.

 

Thanks for everybody's suggestions.  A job well done!

 

Cheers

Dave

[Dave pb]

I forgot to say, while doing the usual internet searching,   I came across a pub "The Radius Arms",  down in Surrey or Sussex or Hampshire. Got to be worth a visit.

Dave

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