Scooterotica

Hi all,

Just putting together the gearbox and drive train etc. in my Super Monza engine (Indian caseing), and the first problem/concern I've come up against is that when building up the gearbox - Casa rear bearing - the loose 4th gear sits about 1.5mm above the matching 4th on the cluster - this is the same on a few different layshafts I have tried ?!

So firstly, is this a problem I should be really worried about?!? (ie. the 1.5mm gap - I've personally never remembered seeing this before on an engine re-build) - I mean, surely the gears should mesh squarely - for want of a better description - otherwise this could be a possible weakness, and they could break (with 30bhp)?! O, and the same 1.5mm gap happens on another gearbox I tried.

I know when tightening up the spider etc. it might pull the cluster through a bit, but 1.5mm, seems a bit optimistic?! I suppose I could put another shim under the cluster, but that seems a bit of a bodge?!

So, do I blame the Casa rear bearing with an Indian caseing, and just add it to my box of old bearings (a bit annoying as it just cost me £25!) or should I not worry about the 1.5mm gap?!

O, and finally, I tried the same gearbox and layshaft etc. in an old italian caseing, with a Riv rear hub bearing, and the 4th gears meshed squarely

I haven't even got as far as endplate shimming, until I've resolved this possible problem.

Any feedback appreciated, thanks

Try another bearing

jason frost wrote:Try another bearing

Thanks for your reply, much appreciated

So, do it take it from your response that you agree that the loose 4th gear not meshing squarely- when initially installed - is a problem I should be concerned about, and something that isn't really acceptable?!

Tom Russell wrote:

jason frost wrote:Try another bearing

Thanks for your reply, much appreciated

So, do it take it from your response that you agree that the loose 4th gear not meshing squarely- when initially installed - is a problem I should be concerned about, and something that isn't really acceptable?!

Umm, anyone have any thoughts on this?! I thought we had a few dealers on this website - sorry if you're all busy with other things - who must see these things all the time

So, what do you all do? Just accept it, or do you have a fix for it??

As recommended, I tried a different rear hub bearing (old Italian), and a few different Italian layshafts and gearboxes, and get same problem, so must be something to do with the Indian caseing

So, just thinking, maybe I get a special gear cluster shim made up - standard = 1.2 + 1.5 difference = 2.7 - to square up the 4th gears, or am I going to then get other problems anyone else had to do this, or do most people just not worry about it

Thoughts on this anyone??

You said yourself that tightening up the spider/clutch will lift the cluster, so I'd do that first and see how the gearbox turns. 1.5mm isn't that much.

Tom.. call charley. He will have a solution.

tony wrote:Tom.. call charley. He will have a solution.

Yep, have done Tony, and both he and Mr. B were very helpful and had some great ideas on how to properly check alignment, which with a combination of trying some different layshafts and rear hub bearings, resulted in all the gears satisfactorily lining up when all assembled and shimmed - and the cluster pulled through the endplate.

Just to be clear to anyone who reads this, there was never a problem with the gears turning, or shimming up etc., it was just the 4th gear didn't sit level with it's corresponding gear on the cluster, which concerned me with 30bhp soon to be going through it!

To be honest, I think i was probably being a bit paranoid, and overly concerned with this alignment problem, and if I wasn't building a Super Monza engine, I doubt I would've been quite so concerned.

Better to be safe than sorry though, I suppose

[/quote]

Yep, have done Tony, and both he and Mr. B were very helpful and had some great ideas on how to properly check alignment, which with a combination of trying some different layshafts and rear hub bearings, resulted in all the gears satisfactorily lining up when all assembled and shimmed - and the cluster pulled through the endplate.[/quote]

what did they recommend you do to check?
cheers
mick

great thread

when you've done a few you will be thinking 'what happened to quality control'.
by the time you have sorted out the first one all the studs will be stripped and helicoiled!
have fun,
regards
joe

joespeed wrote:when you've done a few you will be thinking 'what happened to quality control'.
by the time you have sorted out the first one all the studs will be stripped and helicoiled!
have fun,
regards
joe

You're right there mate, I've already had to replace one of the endplate studs!