sticky shocks

[Guest loren]

Simple question. When compressing a healthy shock, without the spring, should it ever

not return to it normal position? I.e. you push it in 5cm, and it stays there. sometimes

it will come back all the way, but it won't start pushing back until say 50% of the pressure

required to push it in is released. So say it requires 5kg of force to push it down, it will

not start pushing back until the pressure exerted on it is reduced to 2.5kg.

I think a shock that behaves like that is screwed, but I've just got them back from the

rebuilder who swears they are working perfectly... and sent me a shock dyno as proof.

The thing is though, he said they were perfectly smooth to operate by hand... which they

are once they start moving, it's just that sometimes they don't move when expected.

Opinions please.

[Guest loren]

 QUIKGT said:

Depends whether its a gas shock or hydraulic....

hydraulic. is that normal you think?

[Optical]

if you're talking about you ohlins, one of mine is sitting on the lounge floor.. seems to behave as you describe

[Guest loren]

 Optical said:

if you're talking about you ohlins, this is what mine do:

if the damper is turned right down it slowly rises back to maximum extension after being pushed down

if the damper rate is up, it's pretty hard to push down and shoots back up when you let off

yes the ohlins, and on the softest setting... I'll try it on hard. do yours make any noise when moving?

The fronts are silent and smooth as I'd expect, but the rears make a "coming unstuck" type noise whenever

they move.

When jacking up the car, with each pump of the jack, the car and wheel will lift together, then after a pause,

the wheel will drop... same when lowering the car a bit at a time, the car doesn't drop instantly when the jack

drops. It's much less sticky with no tension on the spring though.

any ideas?

[Guest loren]

 Optical said:

if you're talking about you ohlins, one of mine is sitting on the lounge floor.. seems to behave as you describe

interesting. have you had them on the car yet?

[Guest loren]

 QUIKGT said:

Hydraulics have no way of returning to their normal position. Thats what the gas pressure in gas shocks is for.

Sounds normal to me.

hmm, well they do return, and with some force... they're probably gas and oil, most shocks are aren't they?

The issue I have is that they seem to need some encouragement to start moving. once moving they are fine.

[Guest loren]

 QUIKGT said:

I'm guessing that with a tonne of car behind them they'll move quite freely, and loosen up more too.

yeah, but they don't. if I lift the front of the car 2mm from sitting, the wheel doesn't move at all.

the car lifts 2mm and the suspension expands by 2mm. exactly what you would expect.

however, if I lift the rear of the car by 2mm from sitting, the wheel will first lift off 2mm, i.e.

it will move with the car, then after a pause, it will drop back to the ground. not normal at all.

[Guest loren]

 QUIKGT said:

And they are fresh shocks? Not good ones that have been checked over, but all new seals etc?

I bought them second hand. The rears needed a rebuild very soon after buying them.

They were completely rebuilt, and were fine for 3 local tarmac sprints, then started

this weird behaviour again... so i sent them back to the guy who rebuilt them, and

he said they were perfect still and needed nothing doing to them, and sent me

a dyno report showing they were fine.

So I'm trying to deduce if he is full of it, or they are being stress in a non standard

way once installed on the car, which is causing them to act like they do.

[Guest loren]

 QUIKGT said:

So whats actually happening? Back end skipping around?

yep, feels very light back there... they feel like they're actually bouncing right off the gound under brakes and

I've got very little rear traction when accelerating out of hard corners.

[Guest sleeperfoz]

 loren']

[quote name='QUIKGT said:

I'm guessing that with a tonne of car behind them they'll move quite freely, and loosen up more too.

/quote]

yeah, but they don't. if I lift the front of the car 2mm from sitting, the wheel doesn't move at all.

the car lifts 2mm and the suspension expands by 2mm. exactly what you would expect.

however, if I lift the rear of the car by 2mm from sitting, the wheel will first lift off 2mm, i.e.

it will move with the car, then after a pause, it will drop back to the ground. not normal at all.

my v7sti shocks in the forester do this in the rear.

still handles ok.

but when you come to a stop,it will take a few seconds then you hear a bump noise in the rear and they push up.

dont know why like yourself.

i thought they were ok,obviously maybe not :-\

[Optical]

sorry i didnt read your original question properly and edited my response..

have you had them out of the car with the springs off to see what they do?

what ARB are you running on the rear? If the bushes aren't mexican greasy smooth they would cause odd extension of the shock

also if the bush bearing that the damper shaft slides in isnt greased up and within tolerance it could cause that too..

I doubt a shock dyno test would show this sort of thing up as you're witnessing slow tactile movements rather than brutal compression etc

[Guest loren]

 Optical said:

sorry i didnt read your original question properly and edited my response..

have you had them out of the car with the springs off to see what they do?

what ARB are you running on the rear? If the bushes aren't mexican greasy smooth they would cause odd extension of the shock

also if the bush bearing that the damper shaft slides in isnt greased up and within tolerance it could cause that too..

I doubt a shock dyno test would show this sort of thing up as you're witnessing slow tactile movements rather than brutal compression etc

Yep, out of the car now, and they move smoothly when moving, better than when in the car,

but they need encouragement to move.

The rear ARB is an adjustable 22m on hard, but it's currently disconnected and still the shock is the same.

When the shock is in the car, without the ARB or spring, it's a bit better but still not normal. If I jack

the wheel up, then let it go, it will judder it's way down rather than slide smoothly.

So, how do a grease this monkey up... just spray some CRC on the shaft or do I need to dismantle it?

If the shaft isn't within tolerance, then I assume that's a dead shock?

[funkytown]

I know when you were going round back track the other weekend your inside rears were coming well off the ground - check out the other club events for photo proof - so you've not even got all them down on the deck to be giving you traction in the rear.

[Guest loren]

 funkytown said:

I know when you were going round back track the other weekend your inside rears were coming well off the ground - check out the other club events for photo proof - so you've not even got all them down on the deck to be giving you traction in the rear.

Yeah that's because I've got the rear too stiff in relation to the front (trying get rid of the dreaded understeer)

and the shocks have very little droop.

I'll be stiffening up the front and trying a different wheel alignment soon, but am looking at a mechanical LSD

for the rear as well... the stock diff is rubbish when one wheel is off the ground.

[Optical]

all the shock components are in the shiny damper shaft.. that shaft slides in a couple of bushes that sit in the strut housing. I imagine they're easily replaceable for someone who knows what they're doing

that's if it is the problem...

you should be able to get crc past the top seal, but better to unbolt it at the bottom and pull it out. It runs some hefty grease on the inside

[Guest loren]

CRC seems to have helped a bit, but they're still far from smooth. Do you have a link to instructions on how to dismantle them?

As for getting them fixed by a pro, I'm kind of screwed... I just spent $700 on a rebuild by the only person I know of that will

rebuild ohlins shocks, and he says they are fine.

googling about a bit it sounds like dismantling them and lubing them up is what I need to do. I'll give it a go tomorrow.

[Optical]

Yeah Chris, he did some work on mine too after I saw you had been there with yours..

If CRC helped then you might as well get some grease in there. To dismantle unscrew the nut(s) from the bottom, then (from memory) use a screw drive to turn the shaft until you have the spigot loose. Then it should all pull out the top

[Guest]

OK this problem is not incommon at all in inverted shaft shocks

The top bush gets tight with road grime, causing the "sticky" feel also the occasional "thud" can be heard at low speed

Raise the car and clean the shafts down, grease shafts and check operation

I have had a few that needed dismantling and regreasing in the top bush as cleaning in place did fix the fault

Also SOME gas struts are neutral ride, and do not push out (same as hydraulic)

[Guest loren]

Right, now that I have taken the shock out of the strut casing, I finally understand

what the hell an inverted strut is. I must say it seems to be a stupid design.

The shock itself operates smoothly and without sticking, so it must be that the shock

body is the thing sticking the strut casing. It's pretty dirty in there, so will clean it

and grease it up.

It's still very surprising to me that a bit of dirt is going to cause such a profound effect.

I wonder if the clearance between the shock body and the strut casing is too great?

What gease should I use... someone told me just to use vaseline?

[Guest]

It aint a babies butt, so no to the vas ! ;D

Find an HP wheel bearing grease and lube with that

Make sure the shaft seal is all good too

Inverted shaft is very strong for strut set ups as the alot of the vehicle side loading is transfered to the strut

(imagine it into car mounted conventionally, it wouldn't take much to bend ! )

[Guest loren]

problem solved

I think these shocks are going to be a lot of maintenance. The seals seem ok, but am not convinced the

metal ring holding it tight is doing anything though.

Thanks for your help guys.

[DPI]

 sleeperfoz']

[quote name='QUIKGT said:

I'm guessing that with a tonne of car behind them they'll move quite freely, and loosen up more too.

/quote]

yeah, but they don't. if I lift the front of the car 2mm from sitting, the wheel doesn't move at all.

the car lifts 2mm and the suspension expands by 2mm. exactly what you would expect.

however, if I lift the rear of the car by 2mm from sitting, the wheel will first lift off 2mm, i.e.

it will move with the car, then after a pause, it will drop back to the ground. not normal at all.

my v7sti shocks in the forester do this in the rear.

still handles ok.

but when you come to a stop,it will take a few seconds then you hear a bump noise in the rear and they push up.

dont know why like yourself.

i thought they were ok,obviously maybe not :-\

That delay and then bump is telling you that (not uncommonly) your V7 STI rear struts are shagged.

Mine were toast at 60,000km and SUBARU wanted $1300 a pair for new ones, hence why i have coilovers, it was the cheaper option (HUH).

Something to do with the inverted strut being badly designed by either [KYB] or [sUBARU] so as to leave almost no room for a seal.

[Optical]

grab some dust boots to put over the damper shaft, should help. ive got some on mine. if i could i'd seal up the whole damn strut to keep it clean!