Caldina GTT weird suspension clunk

[sam clarkson]

98 Gtt. left rear suspension has a VERY nasty clunk going over SMALL bumps. The tiniest ripple in the road produces a horrendous bang, you'd think the rim had hit the curb. No I'm not running low profile tyres and pressures are fine. Curiously large bumps do not produce a bang. The shocks seem fine, the car does not bob up and down as per a worn shock. Tyre wear appears normal. I have checked the top of the shock and housing, it's all tight. Spring is not broken, resting height is normal (no sag).
I have jacked up and shoved everything around with a crowbar, but I can see no worn bushings or sloppy bolts. Bearing seems sweet.
What have I missed?
Anyone else lived through this scenario?

[Timmo]

checked for silly things like a loose spare tyre or something in the wheel well?

[snwtoy]

Inspected the locking mechansim for the cargo blind?

Also checked the top bolts of the shock (requires removing the plastic trim around the strut tower)?

Can't think of anything else sorry

[fivebob]

I had a similar clunk in my Caldina which progressed into quite violent suspension movement in the left rear everytime it went over a mild bump.

Diagnosed as a worn shock by the local garage when it failed its WOF inspection. It turned out to be a faulty CV joint.

[sam clarkson]

Yeah I've checked all the silly things and all the top mountings. Did that CV clunk on acceleration/deceleration? Mine doesn't.

[fivebob]

Yeah I've checked all the silly things and all the top mountings.

Including all the Sway bar bushings and mounts?

Did that CV clunk on acceleration/deceleration? Mine doesn't.

No clunk on acceleration/deceleration. However I doubt it's the same problem that you have, as mine was acompanied by some quite violent suspension movement when the CV locked up. I guess it is possible that the CV is just letting go with a loud bang not seizing completely.

[Santa'sBoostinSleigh]

if its noise and not vibration, try checking your exhaust isnt hitting your driveshaft

[sam clarkson]

I can now answer this problem...
This car was fitted with bilstein shocks. They are pressed into the rear strut with a retaining collar. This is a faulty design that does not hold the shock in correct alignment and thus allows a certain amount of sideways loading onto the shocks innards. This, in time, has caused the seals to fail and the gas/oil to discharge. It has also caused the shock to seize at the start of it's travel. Hence the heinous crashing over tiny ripples in the road. But once the shock shaft moves the spring functions, thus large bumps aren't a problem.
This faulty design is still current.
Don't buy bilstein for this model car, is the moral of the story.

[cat007]

We have the EXACT same problem

Ours sounds like, imagine you have the spring compressed with spring compressors - then they let go and the spring smashes into the strut seat...or the top hat - it's not a solid BANG - but like smacking something solid with a hollow pole....

We have TEIN adjustables in there - and the left rear is leaking to all hell. Car isn't being driven at the moment because of this - but I'll take it to a shock place as soon as I get a minute....

[Mr Revhead]

I can now answer this problem...
This car was fitted with bilstein shocks. They are pressed into the rear strut with a retaining collar. This is a faulty design that does not hold the shock in correct alignment and thus allows a certain amount of sideways loading onto the shocks innards. This, in time, has caused the seals to fail and the gas/oil to discharge. It has also caused the shock to seize at the start of it's travel. Hence the heinous crashing over tiny ripples in the road. But once the shock shaft moves the spring functions, thus large bumps aren't a problem.
This faulty design is still current.
Don't buy bilstein for this model car, is the moral of the story.

That's not quite right.
they are not pressed it, undo the collar and they will come right out (some have the shaft secured at the bottom by a nut)
While after time they do develop that knock due to sideways movement, its not really a faulty design as you say, its the shock wearing out as it won't happen until you have covered quite a distance. ie over 80k.
Yes the rebuild changes the top collar to last longer, but by 80k they are more than likely past their used by date anyway.
The way you describe it they will fail in a short time.

Of course if it had inserts incorrectly fitted that's another story

[sam clarkson]

You may be right Reverend Head, but I've had Bilsteins in a lot of vehicles over the years and done a lot of k's. Only these rears have done this. The fronts remain as good as new.
I still maintain that the way they fit into the rear strut could be done better. Autolign are modifying the mounting to a threaded arrangement that has more lateral stability. What annoys me is that is an extra charge, I'd say bilstein should do the job properly the first time.

[Mr Revhead]

ah but how long did they last for vs the warranty on them?

autolign charge like a wounded bull, that's why it will cost you extra.
Also they do that to fit the insert they use, improving the mounting is just a lucky by product of that!
Subaru bilsteins do it all round on all models.