SX3 pulley rubbing?

Cardnim · #1 10-07-2012

I've completely broken down my SX3 into the tiniest pieces it will go to in order to completely rebuild for the oOple race.

...and wouldnt you know, like a plonker Im already stuck on Step 2 in the instructions!

Can anyone offer any help as to what Im doing wrong?

Here's the problem:
In the instruction manual it shows just sliding on the bearing and then placing the whole layshaft into the metal housing...

Then, I complete the Steps and place on all the pulleys, the slipper, spur, housing etc and then screw on the steel idlers with the lock nuts.

But now this pulley (the one in the pic above) fouls on the metal housing and drags.

I can see it has actually been happening to the car previously, as the black paint on the housing metal has been scoured off.

Here's where it is happening:

What am I doing wrong?

It feels like in the instruction manual in Step 2B (see pic above) that there should be a little washer/spacer between the pulley and the bearing just to space it out, but there isnt.

Is this a known problem? I've heard about people putting spacers on this layshaft, but thought that was just before the lock nut went on to eliminate the "click".

Any thoughts?

mark christopher · #2 10-07-2012

what if you turn the pulley round on the shaft, is it offset?

bigred5765 · #3 10-07-2012

what mark said may be you have the pulley on back wards ares clears the metal buy 2-3 mm

DCM · #4 10-07-2012

Mine has at least 1mm gap, so I would suggest that there is a difference if you turn it around.

Cardnim · #5 10-07-2012

Quote:

Originally Posted by mark christopher

what if you turn the pulley round on the shaft, is it offset?

Quote:

Originally Posted by bigred5765

what mark said may be you have the pulley on back wards ares clears the metal buy 2-3 mm

Thanks so much for the replies guys. Really helpful.

Interesting point about which way round the pulleys go, but Im fairly confident they are both correct.

In the next step:

you can see that the central pulley has an obvious "squared" part to one side, this is definately correct on mine.

The first pulley (the one thats rubbing) I cant be jsut so sure about, and unfortuantely cant check cause Im in work now.
But Im 99% sure that its right too, as the face of the pulley and the end of the layshaft are completely flush and level for the little M3 washer & locking screw to go on (see Step 2B on first post above)

?

Cardnim · #6 10-07-2012

Quote:

Originally Posted by DCM

Mine has at least 1mm gap, so I would suggest that there is a difference if you turn it around.

Sorry chum, didnt mean to leave you out of the thanks.
You posted as I was typing my reply.
Thanks!

So it sounds like you are all saying the same thing.
That the first pulley, shown in Step2B needs turned round. ie. this one:

correct?

MikePimlott · #7 10-07-2012

Youve not missed off the little crush spacer have you ?

Just another check.

Cardnim · #8 10-07-2012

Quote:

Originally Posted by MikePimlott

Youve not missed off the little crush spacer have you ?

Just another check.

Cheers Mike.
Hmm, the words "crush spacer" sound perfect for this cause thats exactly whats happening. Its all free and lovely until I tighten the lock nut onto the idler gears then it fouls.

Which crush spacer are you referring to?
(sorry for being so thick!)

EDIT --
This one (in pink?)
If so, its definately on there.

MikePimlott · #9 10-07-2012

I actually think that the layshaft has a recess on to stop that pulley from going too far in.

So either the bearing width is too small, the hole the bearing sits in is too deep or the layshaft or pulley is machined slightly out of tolerence ?

You may have to fit a shim to move it out a touch.

Or swap the pulleys round on the center belt see if the fault moves.

Cardnim · #10 10-07-2012

Quote:

Originally Posted by MikePimlott

I actually think that the layshaft has a recess on to stop that pulley from going too far in.

So either the bearing width is too small, the hole the bearing sits in is too deep or the layshaft is machined slightly out of tolerence ?

You may have to fit a shim to move it out a touch.

You are saying all the right things Mike, because I noticed that on that first layshaft, in the instruction manual there looks like a very definate recess (or collar) as part of it.

On mine, this is almost non-existant.

I couldnt believe though that this was wrong, hence why I didnt mention it.

Maybe that is the problem then.
Without this little collar, you think that would allow the pulley to come too close tot he housing and foul on it then?

MikePimlott · #11 10-07-2012

I added A bit more info in my last post

Cardnim · #12 10-07-2012

Thanks again Mike,

Think we are getting somewhere - will know tonight for sure when I get to work on it in front of me.

However, I think I've found a mistake in the manual, and its right at the point of my problem, so maybe this is whats wrong.

TAKEN FROM THE CAT SX3 MANUAL:

Step 5 - showing the 4x6x2.5 spacer going on BEFORE the bearing...

but in the exploded view (also in the manual and online) it shows this spacer going on AFTER the bearing:

So which one is correct?

MikePimlott · #13 10-07-2012

Mine is on before the bearing and this is correct.

The bearing only goes into the metal housing and no further! The spacer passes through the housing and acts as a crush spacer on the layshaft.

I think your problem is solely at the other end of the layshaft

Cardnim · #14 10-07-2012

Quote:

Originally Posted by MikePimlott

Mine is on before the bearing and this is correct.

The bearing only goes into the metal housing and no further! The spacer passes through the housing and acts as a crush spacer on the layshaft.

OK great, thats the way I have mine too.

So I think its back to being either:
a) - my pulley is on the wrong way round
b) - the layshaft collar is missing/broken/gone

Thanks so much everyone for all the help.
Will report back incase anyone else experiences this (though I doubt it!)

DCM · #15 10-07-2012

It won't be anything to do with anything past the bearing behind the pulley, the bearing sits in the bearing holder on the bulkhead, the layshaft slides in upto a lip on the layshaft, so if it is fouling, then it is either the pulley, bearing holder or bearing.

Cardnim · #16 10-07-2012

Quote:

Originally Posted by DCM

It won't be anything to do with anything past the bearing behind the pulley, the bearing sits in the bearing holder on the bulkhead, the layshaft slides in upto a lip on the layshaft, so if it is fouling, then it is either the pulley, bearing holder or bearing.

True.
Never thought it might be the bearing. I'll swap it out. Have a new complete set of SX3 bearings from RC Bearings, so might as well use this opportunity to swap them all out.

Thanks for the headsup DCM

DCM · #17 10-07-2012

No problem, the crush tubes are only there so you don't place any side loads on the bearings when you attach the outer gears.

Cardnim · #18 10-07-2012

Last question I promise!

And should I tighten up those end lock nuts as tight as they will go onto the idler gears? Or is it just enough to keep the gears from wobbling?

(dont know if it matters, but Im going to be using a small spacer between the idler and lock nut to eliminate the "Cat Click")

DCM · #19 10-07-2012

As long as there is no binding, nip them up tight.

Cardnim · #20 11-07-2012

Got it sorted last night.

You guys were spot on; it was indeed the very first pulley, it was round the wrong way and the tiny collar on one side of it was enough to make all the difference.

Its this pulley shown in Step 2B that was the culprit.

A massive (MASSIVE) thanks to everyone who helped me.
It was invaluable guys, and it is very much appreciated.

I just couldnt see thw wood for the trees and was getting lost looking for some werid problem, when it was the simplest thing.
IBut I couldnt have reasoned it out without your advice.

Thanks again.