YZ IT 1980 MONOSHOCK

[TonyB]

OK I decided to take a peak inside my rear shock, nitrogen was already drained, but I got stumped by the end cap (where seal is) which obviously needs to be removed to remove shaft and piston. Does it screw on or is it pressed in??? there is a small slot which looks like maybe a tool fits into it or a start to get something in to pry it open? can anyone help...

[yzhilly]

Hey Tony have you got a parts Pic of the shock ,i a had a look on Yamaha Parts the first cover looks like just a dust cap ,which you can tap off ,its like a trailer wheel bearing dust cap and the head with the seals in it needs to be pushed  down into the barrel and there will be a circlip to remove and then pull the rod assembly out .

[Nathan S]

Yep. It's pressed in, and should just need some careful levering or tapping out. It's main purpose is to spread the load when the shock bottoms out.

Below that is a round section snap-ring which will be a bitch to remove - you'll need a nice sharp scribe (or similar) to get underneath the end of the snap-ring to lever it out. I've got two old screwdrivers that've been sharpened on the grinder (and one has been bent) to help get the snap-rings out. Everytime I used them, I'm paranoid of jamming one deep into my hand, but I've avoided it so far...
I built a basic but effective tool out of a couple of lengths of threaded rod and some scrap RHS, to push down the seal head, so the snap-ring can be removed.
There will be a second snap-ring under the seal head.

Then it should come apart quite easily - in fact, you'll probably wonder what all the fuss is about once you see what's in there.

Check the inside of the body for wear.

[TonyB]

Thanks nathan, yes I figured its probably going to look real simple omce you look inside, i am hoping i might be able to improve the shock myself with an aftermarket piston valve for less money than the going rate which seems to be about $650. My main beef is the compession damping is too high and stutter bumps or square edges kick the arse around something fearfull. Also how much force is required to push the seal holder in to get snap ring out? any chance of a pickie or description of the tool you made up?

[Nathan S]

Will get piccy in the next day or two.

Force isn't huge - locally there's a guy who rebuilds good car shocks and his version of the tool is like one of those old wall-mount can crushers. It's basically just a holding bracket and a lever - and you can only use one hand on the lever because the other one is needed to hold the shock in place.
Lever has a ~5:1 mechanical advantage.

Having said that, I built mine because his wasn't strong enough for a couple of my older shocks (with their nice hard O-rings...).

[YSS]

A complet new  adjustable YSS shock is only $700.00 for that model.

[TonyB]

Walter do you have any photos or information on this shock?

[YSS]

Just hade a thought Tony , if we use just your steel body  ID 46  and your spring ,the rest we use YSS parts , then the cost would only be $450.00 cheers Walter

[TonyB]

Walter if we use my shock with your internals will I get a much better feel to the shock? will it have less compression damping and fully adjustable rebound? I am after soemthing that feels as close to modern bikes as possible, ie very forgiving on compression and adjustable on rebound. i should imagine there is a spring loaded valvel to allow bulk oil to pass on compression when a sudden big hit is taken, otherwise normal wallowing whilst on slightly undulating ground is handled by spring and normal copmpression damping

[YSS]

If you want all that , you need  high -speed low speed adjustment, can be done
just look for the X 506 TRW

[TonyB]

Walter, Could that all be fitted to my shock body as before? or do i need another whole shock, and have you got indicative prices?

[YSS]

Tony , we can go back and forward here a long time , just give me quick call on 08 82848033
regards Walter