Rear shock - is this fixable?

[thomasteacake]

Hello, this is my first post here after a long time using the site as a brilliant resource. I’m hoping to get some technical advice.

The shock pictured here came on a 1995 S Works FSR which I recently picked up. This is my first full suspension retro mtb. The rear shock appears to work fine but is making a squelchy noise when compressing/ decompressing. I suspect seals but don’t really know enough to diagnose and am reluctant to start stripping it without knowing what to expect. Is it toast? Or can I ignore the noise and continue to ride? I suspect it needs replacing but all suggestions welcome.

The shock looks to be manufactured by Mojo. (I’m aware one of the bushings is missing in the photos)

 

[thomasteacake]

 

[mdvineng]

Could be low on oil. The squelching is the gas and oil pushing through the damping control valves, so an oil change might just sort it!

 

[thomasteacake]

Could be low on oil. The squelching is the gas and oil pushing through the damping control valves, so an oil change might just sort it!

That would be a good! Any advice on how I’d go about changing the oil? Assuming through the brass screws under the blue or red knobs? I realise I sound like I don’t have a clue! I’m actually pretty handy but have never worked on a shock before…

 

[mdvineng]

From your picture the piston rod seal is leaking. So I would do an online search for the details and determine if it is actually serviceable, rather than disposable.

 

[thomasteacake]

From your picture the piston rod seal is leaking. So I would do an online search for the details and determine if it is actually serviceable, rather than disposable.

If you mean the mess on the gloves that’s actually from another project (the black marks are dried rust converter). The shock was clean and dry.

 

[mdvineng]

If you mean the mess on the gloves that’s actually from another project (the black marks are dried rust converter). The shock was clean and dry.

Nope, look at the piston rod where it enters the body.

 

[thomasteacake]

thanks, there’s nothing online I can find about this shock so I guess I’ll be replacing.

 

[novocaine]

that will need some fairly special tools to service. this isn't to say it isn't doable, just it will need someone with a bit of know.

not sure if there is a link but Mojo were a fox distributor and service centre in monmouth (I think). I have recollection of them doing a few in their own name. they went by the way side but the name lives on in Mojo rising. might be worth a call to see if theirs a link. I'm fairly sure it isn't the stock shock.

 

[bikeworkshop]

Could be low on oil. The squelching is the gas and oil pushing through the damping control valves, so an oil change might just sort it!

A little of the old oil will have leaked out via the Piston rod, and will have thickened up being 20 years old.
If you could change and or top up the oil, you might find leakage is pretty small if it's for occasional use, you might need to to it up yearly.
Worth trying before throwing it away.

Hopefully that little screw undoes and allows access to the oil chamber?

The classic fix on disposable motorcycle shocks was to drill a hole into the oil chamber, pump out the old oil, get some fresh oil in, and seal the hole with a self tapper.
(Personally I'd tap a thread)

If you find it's coming apart, with any luck the piston seal is a standard 'o' ring, available from a hardware store.

Worth a try before replacement. You might find a replacement shock challenging because travel has increased so much since then