knocking/clunking noise - Bushes

[Marco]

Hi Everyone. I have an intermittent knocking noise which appears to come from the rear. Hard to reproduce but seems to be when I go up an incline at an angle. I went to a mechanic today and got it up on the ramp as initially I thought it may be the droplink (three of four have broken and been replaced so far), but it wasn't that.

He shook the car on the ramp and we could feel a knocking vibration which he thinks is coming from the trailing arm bushes on the back (one side worse than the other), he also advised there is some play in the front ones. He didn't seem to be too sure about this, and although Yes there is a knocking vibration felt when he shook it, I'm not sure that what I'm hearing is that.

I know this is a common issue and I know most people replace them with the polyurethane ones but any advice welcome.

My question is that he claims it is going to take at least two hours each side to replace the rear ones, and an hour each side to replace the front ones. He says the rear would be quicker if he had some special tool to remove the bushes but he doesn't have it. If I supply the parts he will charge me around 50 pounds an hour labour so the rear and front bushes to replace will be about 300 pounds just in labour.

Does this all sound right?

Thanks.......
Marco

 

[Marco]

Feeling lonely out here.....

 

[Machine monkey]

Hi Marco the fronts are easy to do and the rears are apparently quite a bit harder i would say his time estimates are about right. Have a look how much the tool is i am looking to do mine soon so maybe we could do a deal on buying sharing the cost of the tool?

 

[Machine monkey]

I just had a quick look they range from £100 - £400 and there seems to be lots of them I will take a better look this evening. But if he has a press and various bits of scrap tubing it shouldn't be that difficult to remove the bushes.

 

[GuidoK]

which trailing arm bushes on the rear are you talking about?
There are 3 bushes on the rear trailing arm: the front bushing where the trailing arm is connected to the chassis, the lower trailing arm busing where the trailing arm is connected to the lower control arm and the upper trailing arm bushing where the upper control arm is connected to the trailing arm.


For "and an hour each side to replace the front ones" you mean the bushings on the front control arms?

All in all it seems like a lot. If you do all he saves time by putting the car only 1 time on the lift. The front ones are reasonably easy depending on the tools he has and what he does.

 

[synthedup]

Iv never changed the rears so can't comment, however I have changed the fronts and this took no longer then 45 minutes to do both and that with a trolley jock and not a ramp.

 

[RJS-Z4]

The rears (the big main bushes that are "inside" the body) are a real pain in the ass. I changed mine and had to resort to fire to burn the old bush out and fit the poly bushes.

 

[GuidoK]

I did the rear main bushings too, but I popped them out with ease; with a universal bushing extractor set. Maybe 20min work.
They are a tight fit, but the universal extractor can apply more than enough force, and you can position the extracor cups very good on that spot.

The ones by the brake (upper/lower control arm) are more difficult as they are situated under an angle, and if you dont have the bmw extractor, the rear disc dust plate is blocking the access. So that requires some work (remove disc, loosen dust plate (probably rusted shut) etc)

 

[Marco]

Thanks chaps, love this forum! I think it would be prudent to swap out all the bushes at the rear while doing this work, is there a complete bush kit (polyurethane) that anyone can recommend?