Lancia Motor Club

Model Technical and Interest => Aprilia, Ardennes and Ardea => Topic started by: davidwheeler on 18 February, 2016, 03:38:08 PM



Title: Klonk
Post by: davidwheeler on 18 February, 2016, 03:38:08 PM
There has been, for some time, a clonk in the right rear suspension which I am entirely unable to locate.    The only abnormality I can find is some deterioration in the front spring suspension bush 49603 but what is it made of, rubber??  and where would I find a new one?


Title: Re: Klonk
Post by: JohnMillham on 18 February, 2016, 03:51:11 PM
David, you can see on Tav19a it's a Silentbloc bush. So it will have rubber in it. If you can supply the metal bits, Hills Rubber Company in Reading will be able to put the rubber in. Or try Cavalitto?
Regards, John


Title: Re: Klonk
Post by: Parisien on 18 February, 2016, 03:56:46 PM
Or you could try this company (catalogue link below) who've supplied bushes for the Aurelia, the.cern (Andy) kindly pointed me in this direction.

http://www.robush.co.uk/pdf/1519%20Robush.pdf


P


Title: Re: Klonk
Post by: Sliding Pillar on 18 February, 2016, 04:08:06 PM
The only way you are really going to find out is by taking the tension off of the spring.
I would have thought it was quite likely to be the trailing arm bearing, 48307


Title: Re: Klonk
Post by: BlueSky on 18 February, 2016, 04:12:57 PM
If the "klonk" is mainly on the right side I'd suspect the shock absorber, you could test it by removing the mounting bolt from the trailing arm and giving the car a run. Cavalitto do have all the silentblocs for the rear end if you need them.
Noel


Title: Re: Klonk
Post by: simonandjuliet on 18 February, 2016, 04:22:55 PM
If you decide it is the silent block, Robush have them (fitted them on my car) and they weren't expensive - £7 each or something like that - I think I referenced it on the "Aprilia Diary" a couple of years ago


Title: Re: Klonk
Post by: JohnMillham on 18 February, 2016, 04:50:05 PM
I have found that Robush use a less flexible rubber than Mr Lancia used to use, so they are not as good as the originals for steering applications, but they would probably be OK in this case.
Regards, John


Title: Re: Klonk
Post by: davidwheeler on 19 February, 2016, 12:33:37 PM
Definitely not the shock absorber.     The trailing arm bearing is a possibility though.   But first, the silentbloc as it is soaked in oil from the final drive and is clearly eccentric!


Title: Re: Klonk
Post by: Sliding Pillar on 19 February, 2016, 05:56:47 PM
When does it Klonk most? is it on a trailing throttle? If it is, then this is when you are more likely to get the noise from a worn trailing arm bearing.


Title: Re: Klonk
Post by: the.cern on 19 February, 2016, 06:59:01 PM
Definitely not the shock absorber.     The trailing arm bearing is a possibility though.   But first, the silentbloc as it is soaked in oil from the final drive and is clearly eccentric!

'Clearly eccentric' ... surely that is normal status for members of the LMC. Astute and discerning are also appropriate adjectives, but eccentric is a must!!!!

                               Andy


Title: Re: Klonk
Post by: ben on 19 February, 2016, 08:11:42 PM
Hi David
            The silent-blocks in the middle of the spring are a most unlikely source for your noise because they are under constant load and the load is always in the same direction.  Those on my car are also oil soaked and distorted but they don't clunk.

            My bet would be the trailing arm bearing as Ade suggests which would allow fore and aft movement between driving and coast or over-run but it does probably require releasing the spring load to check.

            I had one occasion when clunking occurred due to failure of the rubber in the silent block bush that locates the inboard end of the tube around the torsion bar (49607)on one side.I effected an emergency repair by sliding in a bit of split plastic tubing.

           The above suggestions pre-suppose you have eliminated the more common causes such as drive shaft splines or UJ.s or worn or loose wheel bearings.   

                          Ben


Title: Re: Klonk
Post by: davidwheeler on 20 February, 2016, 09:42:55 AM
It is actually when going over bumps.   The clutch is awful and also induces the clonk when juddering violently but other wise it does not matter if it is pulling or on the overrun or transiting between the two so I suspect the trailing arm bearing may be the culprit.   It is certainly not drive shaft or wheel bearing.   It actually sounds as if there is a loose can in the boot but there isn't!    It really ought to be shock absorber but it is not that either.      Don't have access to the pit at the moment so I shall continue to drive Aprilia as it is my only car on the road (apart from Sheila the Lambda tourer and she only comes out if the sun is shining - which ain't often at the moment!)


Title: Re: Klonk
Post by: the.cern on 20 February, 2016, 11:17:45 AM
Idyllic!!! Cold, but idyllic!!!