'Clunk' noise from front shock absorber(s)

mrtask

Well-Known Member
#1
After recently replacing the steering idler and both side steering arms my car was still making a nasty metallic 'clunk' somewhere in the front suspension. Couldn't find any play in the other ball joints, so I took off the passenger side front shock. With the lower end clamped in a vice and the thing extended to it's maximum length I was able to reproduce the sound, albeit only once, so I've re-fitted it to the car, and I'm happy to report the 'clunking' is no longer present (for now at least!). Pondering on this strange phenomenon and it's seeming to have ceased, I wonder if lifting the car on a two-poster lift is maybe not such a good thing? With the front suspension thus dangling, the shock then reaches a length it never would on the road under the weight of the car, and I'm wondering if something in the gas-filled shock's mysterious innards took unkindly to being 'stretched out'...? Or could it just have been that the locknuts holding the heavy duty shocks on to the beefed up lower mounting point had come loose, and the lower eyelet was where the noise was actually coming from...? I was able to tighten the drivers side locknut a couple of turns, suggesting it had maybe loosened. I've used loctite to help keep it tight now.
Slowed the rate of damping in the front shocks a few more turns now that the steering isn't sloppy anymore, and it is a pleasure in the corners again!
 

harveyp6

Well-Known Member
#2
mrtask said:
Pondering on this strange phenomenon and it's seeming to have ceased, I wonder if lifting the car on a two-poster lift is maybe not such a good thing? With the front suspension thus dangling, the shock then reaches a length it never would on the road under the weight of the car, and I'm wondering if something in the gas-filled shock's mysterious innards took unkindly to being 'stretched out'...?

The only problem with your theory is that with the suspension hanging, the damper isn't stretched, it's compressed......

Maybe being forced closed caused the problem then...

mrtask said:
Or could it just have been that the locknuts holding the heavy duty shocks on to the beefed up lower mounting point had come loose, and the lower eyelet was where the noise was actually coming from...? I was able to tighten the drivers side locknut a couple of turns, suggesting it had maybe loosened.

That's more likely.
 
#3
Hi,

I seem to remember you had some larger mounting eyelet dampers made up for your car? As you know we use the same heavy duty damper mount as you. It’s not a good conversion and if we could easily reverse it we would. The damper moves in more than one plane during suspension articulation and unfortunately this mount only allows rotation. If we do the nut up tight our standard sized eyelet fatigues and breaks, we have to leave it loose and you can hear it rattle. Are you sure you have enough free movement with your setup to prevent failure?

Thanks, Tim
 

mrtask

Well-Known Member
#4
Harvey, I know the shocks work the opposite way than 'normal', but I just can't bring myself to describe the maximumn extension as actually being maximum compression, it just doesn't seem/sound right! My other theory concerns dinosaurs having great big bodies and tiny little brains. Wish I could remember where that comes from. Monty Python? I digress. Is it possible for a gas filled shock to not want to get fully compressed without something inside it ending up in the wrong place/at the wrong angle/whatever, leading to a clunk? I would have tended toward the lock nuts having loosened as the source of the 'clunk', were it not for us having reproduced the noise with the shock off the car.
Tim, I understand Classeparts now offer the lower shock mount reinforcement as a bolt-on modification, obviously preferable, like yourself I'd remove this welded-on 'improvement' too if it were easy to achieve! Alas, it would seem to be on there for keeps, or until I can convince my favourite bodywork metalworking wizard to do something about returning things to standard. Live and learn, eh? I can't leave the shocks loose, the noise would drive me mad, and the oversize eyelets would fail soon enough, I fear. I don't know how to establish if I have enough free movement, other than doing it up tight and seeing if it lasts the course, so to speak!
 

mrtask

Well-Known Member
#5
The 'clunk' has returned, so now I'm thinking the shocks are shagged. Particularly irksome is that the noise became apparent within two years of me fitting the Gaz shocks, i.e.in the warranty perios, but it took me so long to locate where the 'clunk' was coming from that they're now out of warranty.
I'll probably end up sending them back for inspection and will see what they say, perhaps they'll offer me a good price on a repair or replacement.
I thought I'd ask you chaps for suggestions as to alternative shock absorber suppliers, given that Koni don't do P6 shocks any more, and also that I'll need a special order with a different, larger lower eyelet. Anybody care to recommend another manufacturer?
 

quattro

Administrator
Staff member
#7
I fitted a pair of Avo shocks and they were a pig to fit. The mounting pin on the car was too small so they sent me a pair of sleeves to pack them out a bit. They still clunked and knocked so much that I threw them away and refitted the standard ones.

:shock:

Richard
 

Demetris

Well-Known Member
#8
It is a pity that two different manufacturers went into the trouble to make new adjustable P6 shock absorbers, while with non adjustable ones but of decent fit and quality would certainly earn plus points and help more owners.
 

mrtask

Well-Known Member
#9
After a few weeks clanking about with old Gabriel oil filled front shocks attached with ever-so-bodgy self-made bushings, I got my GAZ shocks back, rebuilt, now with different innards apparently, and fitted them today with new Superflex poly bushes. Ride is once again very nice. Shocks adjusted to the middle position (of 40+ clicks from soft to hard). Bushes well and truly lubed with copious amounts of Superflex grease. The result: it feels nice! Cost just under one hundred notes plus postage to have them rebuilt as they were just out of warranty. Here's hoping they last longer than only two years this time...
 
#10
After recently replacing the steering idler and both side steering arms my car was still making a nasty metallic 'clunk' somewhere in the front suspension. Couldn't find any play in the other ball joints, so I took off the passenger side front shock. With the lower end clamped in a vice and the thing extended to it's maximum length I was able to reproduce the sound, albeit only once, so I've re-fitted it to the car, and I'm happy to report the 'clunking' is no longer present (for now at least!). Pondering on this strange phenomenon and it's seeming to have ceased, I wonder if lifting the car on a two-poster lift is maybe not such a good thing? With the front suspension thus dangling, the shock then reaches a length it never would on the road under the weight of the car, and I'm wondering if something in the gas-filled shock's mysterious innards took unkindly to being 'stretched out'...? Or could it just have been that the locknuts holding the heavy duty shocks on to the beefed up lower mounting point had come loose, and the lower eyelet was where the noise was actually coming from...? I was able to tighten the drivers side locknut a couple of turns, suggesting it had maybe loosened. I've used loctite to help keep it tight now.
Slowed the rate of damping in the front shocks a few more turns now that the steering isn't sloppy anymore, and it is a pleasure in the corners again!
hello, just wondering if you had original type shocks or how old they were!?
i have a horrible rattle/knock in what sounds like the lhs front to front / i have changed ams and ball joints, was thinking the damper was at fault but now you have mentioned shocks.....

ta
 

mrtask

Well-Known Member
#11
hello, just wondering if you had original type shocks or how old they were!?
Hello Superdiz.
I fitted GAZ adjustable shocks in 2012 when I finished my restoration and got my car back on the road. I had beefed up the lower shock mounts with a threaded sleeve, and a big locknut holding the shocks in place rather than split pins. I initially used super hard bushings out of a solid white plastic called Delrin. I broke a shock eye. Returned the shocks to GAZ, and they removed the lower eyes and fitted one size larger. I switched to Superflex poly bushes, but I had to halve them to fit them. After a few years one of the shocks developed a nasty noise, so back they went for new internals. Since then I've had no further troubles.
Have you changed your steering side arms? I had that done recently, when my mechanic told me the ball joints were knackered. That just made it immediately apparent that the ball joints in the steering track rod were also bad. Quite a gnarly knocking noise, actually. My guy is fitting a new track rod at the moment, which will hopefully quieten the noises down again.
Check your steering idler is still good, i.e. still has oil in it, and make sure the mounting bracket hasn't come loose. That's happened to me a few times! If the idler is soaking with oil underneath, it's probably toast I'm afraid.
Shock bushes can harden and crack with age, leading to knocking noises.
Let us know what you discover when you investigate further.
 

GRTV8

Well-Known Member
#12
Hello Superdiz.
I fitted GAZ adjustable shocks in 2012 when I finished my restoration and got my car back on the road. I had beefed up the lower shock mounts with a threaded sleeve, and a big locknut holding the shocks in place rather than split pins. I initially used super hard bushings out of a solid white plastic called Delrin. I broke a shock eye. Returned the shocks to GAZ, and they removed the lower eyes and fitted one size larger. I switched to Superflex poly bushes, but I had to halve them to fit them. After a few years one of the shocks developed a nasty noise, so back they went for new internals. Since then I've had no further troubles.
Have you changed your steering side arms? I had that done recently, when my mechanic told me the ball joints were knackered. That just made it immediately apparent that the ball joints in the steering track rod were also bad. Quite a gnarly knocking noise, actually. My guy is fitting a new track rod at the moment, which will hopefully quieten the noises down again.
Check your steering idler is still good, i.e. still has oil in it, and make sure the mounting bracket hasn't come loose. That's happened to me a few times! If the idler is soaking with oil underneath, it's probably toast I'm afraid.
Shock bushes can harden and crack with age, leading to knocking noises.
Let us know what you discover when you investigate further.
Unbeknown to me, the steering Idler bracket on my P6 came loose against the bulkhead. A lot of clunking on opposite steering lock.
I couldn't see it by looking and it sounded like something was going on near the suspension on the passenger side -RHD car
While getting a WOF inspection for road safety the "man" found the movement in the idler bracket with the help of a mechanic with a torch.
Tightened the bolts up and no more clunking in that area.
 
#13
My other theory concerns dinosaurs having great big bodies and tiny little brains. Wish I could remember where that comes from. Monty Python?
The theory you referred to there was actually that the Brontosaurus is very thin at one end, gets much much thicker in the middle, then gets thin again at the other end. This is the theory & this is what it is & it is on Monty Python's Previous Record.
 

cobraboy

Well-Known Member
#14
I cut the mounting eyes off an old original pair of shocks and welded them to a new set of AVO shocks. Was easy to do and along with a threaded lower pin has eliminated rattles from them once and for all.

Sorry, no dinOSaur anecdotes.
 
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