Clunk noise from front strut?

[gturner008]

Wonder if anyone can shed light.

My 72 ST has developed a quite loud knock/clunk from right front area.

Given most parts are new, and I’ve checked absolutely everything in that area, the noise seems to be coming from the strut itself. I have green Bilstein.

Does anyone know if they can have an issue inside that might cause an issue? The strut and insert are fairly new. No oil leak signs.

Something undone inside?

Many thanks. Gary

[sladey]

I’ve got a later car with bilstein inside a Boge strut so this advice may not be relevant but

On mine there is a threaded ring that holds the shock into the strut. That can come loose and give the clunking. On mine I could use a plumbers pipe wrench to tighten it up

HTH

[jb]

I had something similar happen on mine with a big clunk every time I went over a hump so I took it to Tuthills who tightened it up just as Sladey suggests.

[gturner008]

Many thanks. I guess I remove the strut and then take off the top shield and I’ll be able to the thread?

Cheers. Much appreciated

[gturner008]

Now I’m probably being thick here. But I’m not sure what you mean by threaded ring keeping strut to insert.

If I remove the top nut and roll pin, won’t the insert just pull out? Ie. There is no threaded ring keeping then together?

[hot66]

do you have a boge strut with bilstein insert ?

or a bilstein strut with bilstein insert ?

The designs are very different

[sladey]

With mine I was able to sort it with the car jacked up and wheel removed. The insert goes into the strut and is held by the threaded ring at the top.

Regardless of which type, jacking it up and taking the wheell off should help you see if the insert isn’t tight in the strut

[gturner008]

It’s Bilstein both.

With car jacked up, wheel off, if I get a bar and lift the assembly, then push the bar up and down I get it to make a knocking sound. The top nut is tight, along with the Alan bolts. So is the wedge bolt and roll pin.

So I’m confused when the play is coming from

[Nick Moss]

Feel each part of the assembly with your finger as you instigate the play, you will be able to isolate the knock.

[gturner008]

The knock seems to be coming from inside the strut. Everything is tight as a drum. The parts are only 5k miles old. All nuts and bolts and pins secure. The knocking noise is bad. I drive over a small bump on the right side, bang. It’s not a bang like something is loose (like oil cooler) it’s a bang like metal to metal.

Very odd. Three times now I’ve had the car up on the hoist. Three times come away baffled.

[fetuhoe]

You clearly have Bilstein Struts. which as Bootsy says are very different in construction to a Boge strut with a Bilstein insert.

The insert you have is 40mm diameter and has a piston rod located with a roll pin.

The 40mm insert slides in a pair of DU bushes located in the strut casing. Depending on the age of the strut there is a wiper seal on the top of the casing.

In the early strut it is held in place by a simple chrome plated ring pressed onto the casing and on the later strut it sits in a relatively large diameter housing.

If you remove the wiper seal you will see the upper DU bush. The lower bush is towards the bottom of the insert.

These DU bushes wear and allow the insert to move relative to the casing and then they develop a 'clunk'.

The best way to resolve this problem is to replace the DU bushes but their removal is a real PITA without special tools.

The common 'bodge' is to fit a single new DU bush into the top of the leg and leave the old bushes in place.The new bushes supplied by Bilstein are now only 20mm long. They used to be 40mm long and they are readily available from many bearing suppliers.

[gturner008]

Many thanks.

I thing I’m best getting the car to a decent specialist. They will do this job and also set up the ride heights. It sounds a bit beyond my DIY skills!

[gturner008]

Ok. Sorted.

Bilsteins were 930 ones. The roll pin had not been put in properly and didn’t lock in the insert. New roll pin. Now perfect