Thread: Expected shock absorber life

After all that, bottom line is that cheaper dampers are really only good for about 50,000km if you're lucky.

The old rule of thumb with cars used to be when you change your tyres your dampers/shockies/struts were due too.

Quality ones should last considerably longer (depending on use/abuse )

Originally Posted by PeterM

It's important to remember that dampers are a hydraulic unit with seals, fluid etc.

If they sit or are used infrequently, you can encounter issues of seal hardening and leaking of fluid past the seals. The hydraulic fluid itself also degrades over time.

[snip]

The fluid actually shears in use thanks to being forced through the orifices in the piston/valves.

It will probably oxidise with high heat cycles too, and damper fluid, just like all lubricants varies considerably in quality/characteristics depending on base oils used and additives.

Thanks Rick, great info as always. What oil do you recommend for rebuildable shocks?

I have a battle at times convincing people to spend the money once, on good shocks. By Good I mean Koni, Bilstein, DeCarbon . These are IMO the better off the shelf brands available. I have used DeCarbon on my rangie and now the county for years and very happy with them, have sold many sets too based on my experience with them and if it wasn't so hard to get them now I would keep doing it. Not 1 warranty claim on any, only one that leaked was the result of a MVA, and it still worked.

JC

Agree jc, and if only I could find the correct part numbers, lengths and valving online I'd have a set of raid 90's sitting in the shed awaiting to go in
(Gu/80series combo)

Originally Posted by flagg

Thanks Rick, great info as always. What oil do you recommend for rebuildable shocks?

IME Silkolene Pro RSF or Motul Factory Line Shock Oil in the appropriate viscosity.

I've found Pro RSF 5wt to be an excellent substitute for Koni fluid (Shell).
It gives you the right characteristics at room temp according to my rudimentary viscosity tests (leak rate at various fluid temps through a fixed orifice, then confirmed by someone with inside Koni info ) with much, much higher performance.
It improves the fade performance of a Koni twin tube like you wouldn't believe.

Torco make a good fluid too, although I've never used it. Fox Racing Shox use Torco.

There is a higher performance fluid that a small US blender makes that outperforms all the mainstream stuff in terms of viscosity index but I've never used it although I trust the blender.
Bruce the blender condescendingly calls Silkolene 'Sockolene'
He's switched on and has been a really good help in the past with my understanding of lubricants.

Originally Posted by rar110

I've just returned from a big trip to find the rear shocks are not working (front is probably the same) in that the mo longer rebound, and the top bush on one is flogged out.

These are a big bore quality gas shock with a known name.

They are about 7 years old but have only done 55,000 km. Most of those km have been on good roads other than maybe 5000 km from the last trip which saw quite a bit of corrugations etc. I have done a few other offroad trips but not many. Early on during the last trip I started checking the rear shocks for heat. They were warm but not too hot to touch. At that time I noticed some movement in the top mount so tightened it as much as I could.

So my question is generally how long should I expect a shock to last.

I have contact to the head office who is sympathetic, said the should last more Km but their age is an issue. They offered a $100 discount off another rear set.

Is it a foam cell shock? I don't think that construction ever recovers from being run hot.

Originally Posted by justinc

I have a battle at times convincing people to spend the money once, on good shocks. By Good I mean Koni, Bilstein, DeCarbon . These are IMO the better off the shelf brands available. I have used DeCarbon on my rangie and now the county for years and very happy with them, have sold many sets too based on my experience with them and if it wasn't so hard to get them now I would keep doing it. Not 1 warranty claim on any, only one that leaked was the result of a MVA, and it still worked.

JC

At a guess The Ultimate Suspension's shocks should be a really good substitute for deCarbon (or any other brand)

They used to be a deCarbon importer, supplier and rebuilder, but now make their own mono-tube dampers in-house here in Australia at Minto, south west of Sydney.

When shocks come up in discussion I always forget about them, but they (Ken O'keefe) have been at the forefront of 4WD suspension development here in Australia since the seventies.