Creaky back end

[supersix]

My Cerb, that is, not me.

Anyway, recently there's been a loud creaking from the back of the car when going over even the slightest uneven road. It's a '98 4.5. I've just lifted the back end (first time I've had to get a jack to the car apart from servicing, not bad in 3 years!) and taken the wheels off for a look. Everything looks fine, no leaks from the shocks, nothing loose. The only two things I can find are a few mm of shiny white powder coating visible above and below the top diff mount surrounded by the usual layer of dirt you'd expect, suggesting the bush is on its way out. Also the ends of the anti roll bar have clearly been rubbing the bodywork behind when the car squats under acceleration.

I'd appreciate some idea of whether these are normal or likely to be the source of my creaking?

[gruffalo]

I had this a few months ago, it turned out to be dry antiroll bar bushes.

[TimJM]

gruffalo said:

I had this a few months ago, it turned out to be dry antiroll bar bushes.

I would have thought a worn diff bush would be more of a knock that a creak so I would go for anti roll bar bushes too. It could be the bar catching on the bodywork is another symptom if they are worn out and the bar is moving just enough to catch.

For the sake of £30 and probably less than an hours work I would just fit some new ones.

[supersix]

Sounds like a sensible thing to check (wonder why I didn't when I was under there...) Presumably as long as the car's level I can just unbolt the arb as it should be unloaded?

[TimJM]

supersix said:

Sounds like a sensible thing to check (wonder why I didn't when I was under there...) Presumably as long as the car's level I can just unbolt the arb as it should be unloaded?

From what I recall when taking the back end apart on mine I would:

• jack up the rear and put on axle stands (using chassis tube to outrigger)
• undo the top drop link bolt the anti roll bar connects to on both sides (I think that is where it should connect too - mine was disconnected)
• undo the two smaller bolts holding the anti roll bar plate on both sides

The anti roll bar will be free now - it may be a little stiff/stuck but just knock it out with a mallet.

Then:

• cut off the old bushes with a sharp knife (stanly blade works well)
• slip the new ones over the anti roll bar ends (using grease) and slide into position
• bolt the bar back into position with the two plates
• bolt the drop links backup

Done.

[Supateg]

In theory yes, I found a touch of pre load on mine.
Drop links might be seized on yours causing a stress creak also.

[supersix]

Okay, I'll get back under the car, check the state of the drop-links and find out what diameter arb I've got for ordering up some new bushes. Thanks for the pointers chaps

[Mad Mark]

My roll bar bushes did creak at one point i just gave them a spray with something and all was good after.
You can run the car quite happily with the roll bar disconnected.

Disconnect the drop links tie the roll bar up so it doesn't knock on the suspension same with the drop links and go for a drive. if the creaking has gone you know you have isolated the noise and can go from there.

[Cerbieherts]

The original factory fit shock absorbers are also a cause of a creaking noise when they partially sieze.

[Ireland]

Also check the rear ARB mounting brackets as they can crack / break but everything still looks like it's in the correct place.

Both sides cracked on mine at different times

If this is what's wrong then it's a fairly straightforward fix once you've got a new bracket

I made up my own from 3mm steel plate (that's what TVR used for the originals) and extended it a bit to strengthen it a bit more at the mounting points

I've put a sketch with dimensions, etc on it for what you need and how to do it in to the equivalent parts stickie thread

[supersix]

Thanks chaps Hopefully I'll actually find some time to get into the garage this weekend coming. Time's been a bit tight lately...