Cat SX Shock building guide

[Chrislong]

http://www.jespares.com/guides/shock-rebuild-guide.html

Its on the JE spares website in the FAQ's>Guides section.

[Swiss]

Where did you get those nice looking castor blocks from Chris? Presuming the car in the picture is your car??

[Chrislong]

They are from Schumacher mate, JE Spares has 1 pair in stock ;). They are 7.5 degree whereas the kit plastic ones are 10 degree. I love the alloy ones btw!!!

[Swiss]

Part number? :)

[DAVIDZX5]

Here it is (U3404)

[Minster68]

Great guide, this may seem like a stupid question but i have never really understood the black art of building shocks, so what difference to the handling will the rebound have on the car..

Thanks

[Chrislong]

Well the bit about rebound was not added by me :blush:, as I don't believe in using it as a setup, I believe in building shocks which work properly and are equal left to right. So I intend to get that amended on Tuesday when I am back in the shop.

What it should say, is start to screw the cap on so it finds the threads on the body, then tip the shock 45degree so the bleed hole is held high, then push the shaft in to 2mm away from fully in. Then while holding the shaft still so pressure is released through the hole, tighten the shock by turning the body, not the cap.

There should be no pressure in the shock, if you can't push the shaft right in without feeling pressure then loosen and retighten the cap.

When done, when you push the shaft in it will come out slowly by about 2-3mm. When pulled out it should pull the shaft back in by 2-3mm.

If you were to do like the tips suggest, and tighten the cap with fully extended, the shock would end up almost locked solid with pressure. Having pressure in the shock is bad, it'll blow out the seals if put on the track.

Anybody need anything clarrifying then do please speak up.

[Minster68]

Thanks Chris,

That makes a lot of sense, I've been building my shocks all wrong.. I will be rebuilding my shocks tomorrow..:D

Gordon

[Chrislong]

No worries mate. Hope it all helps. I am going to be doing diffs tomorrow, there is less 'voodoo' to these - quite straight forward, but who knows - I may suprise myself while doing it. :blush:

[carlin]

Hi Chris,

Great instructions.

My question is how do lot make sure you dont get loads of air in your shocks when building with cut out diaph, ive given up tonight.
I must of rebuilt these shocks five times everytime they feel nice soon as i push the shaft all the way boom air shocks are pants.
Ive gone back to using full dia, any tips anyone getting these right or just pot luck when building them?

[geerno]

;);)

[Minster68]

Chris,

Another quick question on the shock rebuilding, do you use the standard o-rings? I have never been able to stop my shocks from leaking.

Thanks

[glypo]

Cool guide:thumbsup:

Shame about the watermark ruining all the images :(

[Chrislong]

Chris,

Another quick question on the shock rebuilding, do you use the standard o-rings? I have never been able to stop my shocks from leaking.

Thanks

Nope, get in touch with Northy from Nor-tech Racing, his white O'rings are awesome. They are smooth and last ages! The way I build them with the light oil for lubrication, means they show signs of leaking for the first 24hrs. But once wiped and the light oil has come out, then all is sealed and well.

[Chrislong]

Cool guide:thumbsup:

Shame about the watermark ruining all the images :(

Can't help that mate, sorry. But if the watermarket is hiding something you want to see just ask and I'll clarify. ;)

[Minster68]

Thanks Chris, I will have to get some from Nor-tech then.

[nickhudson]

i have compared the std schumacher 'o' rings and the nortech versions. there is a huge difference in the amount of 'stiction' - the nortech ones are so much smoother and leak a lot less.

there is one thing that i have noticed - i have run my CAT for only 6x 5 min runs and the supposed 'nitride' coating is already wearing off the shock shafts :cry:. my S2 has run for the same amount of time on the same track (coventry astro) with new losi shocks and shows no wear whatsoever. i have to say, the overall quality of the schuey shocks is pretty poor in comparision. the shock bodies are poorly finished internally (plating burn marks on the bore and pretty rough surface finish), the seal retaining caps are waaayyyy too thin on wall thickness (why aren't they the same o/d as the shock bodies to give them some strength ? - i've stripped one already before it was finger tight). its a shame really - i'm thinking of going over to losi shocks on the CAT because of the quality issues.

[Minster68]

I would have to agree on the shock finish. The plating on mine is terrible also, but the shafts are fine, mind you the seals don't touch them with the amount of oil I'm loosing.:woot:

Apart from the shocks I have been really impressed with build quality of the Cat.. hopefully the Nor-Tech seals will sort things out..

[Chrislong]

The gold on mine is wearing off, but I have used the car regular since September! Although I know with Losi shocks the gold would still be on. Saying that, but im not bothered about it, they are just as smooth now as they were before the gold wore.

I agree on the internal finish of the body, notice the oil is filthy very quick - on inspection the oil looks metallic, thats cos it is, due to the internal bore of the shock.

Ive never had any issues for me to think about stopping running them, I find they are very easy to work on and are as smooth as I can make a Losi shock (which is smoother than AE but I never have liked them). My only confusion is the debate of old vs new springs. I am beginning to think the old red rear and grey fronts are better than the new equivalents.

[JackWood]

Hi Chris,

Great instructions.

My question is how do lot make sure you dont get loads of air in your shocks when building with cut out diaph, ive given up tonight.
I must of rebuilt these shocks five times everytime they feel nice soon as i push the shaft all the way boom air shocks are pants.
Ive gone back to using full dia, any tips anyone getting these right or just pot luck when building them?

Chris,

Can you answer this question please, as it is the same one I have. How do you get enough oil in so that there is no pocket of air left in the cap? Where the cap screws down to on the shock body, leaves an un-filled pocket in the cap. How does that void get filled when you screw it all together when the diaphragm is cut?

[MattW]

Personally, i do it something like this:

Fill shock body

Place (cut) diaphram on top of body

Screw cap on half way

Push piston up, until threads are in the region of 5mm from the bottom of the shock

Screw cap all the way down

That way, the area you talk of that you have filled with air, is now filled with oil.

[BlackedOutMugen]

Those purple caster blocks are sick! I need to get me some:p:p:p:thumbsup::thumbsup::thumbsup:

I build my shocks the same as he did in the guide. My shocks have no air at all, and dont leak one bit! And there smoooooooth as can be. I love it!:thumbsup::woot:

[mikeyscott]

What ball cup lengths are people using?

[bigred5765]

full length ones cut to 3/4, front and back

[mikeyscott]

full length ones cut to 3/4, front and back

Full ball cup = about 19mm

so that would mean you are using 14.25mm ball cup?

[bigred5765]

never measured them but sounds about right,

[Chrislong]

Why not just buy the right part of Schumacher? Cutting isn't accurate enough for my liking.

[bigred5765]

didnt think schuy made them 3/4
length chris??

[mikeyscott]

Why not just buy the right part of Schumacher? Cutting isn't accurate enough for my liking.

Yes please tell us the part number

[mikeyscott]

http://www.jespares.com/faq/6-guides/14-shock-rebuild-guide

updated link