Removal of 1st Motion Shaft and Mainshaft
Turbo Mini Forums

I'm stripping and rebuilding my gearbox to make sure its in perfect working condition before it gets slapped on the engine.

But having removed all other parts, I can't get the mainshaft out.

From what I can tell I need to remove the 1st motion shaft which is the last piece to be added to the mainshaft and is simply drifted into position - can't seem to drift it back off though.

Removing the 1st motion shaft should then let me remove the rest of the mainshaft and then complete the rest of stripping the box.

Has anyone had any experience in how to get the mainshaft out and apart?

Any help much appreciated.

Have you removed the big circlip?

I seriously doubt it!

Yes i have

Put your drift on the outer edge of the bearing, from inside, and give it a good hard whack - it should come out

I seriously doubt it!

Will do. I'll let you know how i get on

SO!
Good news: First motion shaft out eventually!

Bad news: I can't get the main shaft out because I think the mainshaft bearing it preventing me from pulling it out.

I can't get any angle on the drift to force it out with all the gears in the way.

Should the shaft just pull out or is it necessary to get this bearing out first?

Some pics of what i mean:

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Edited by carts60 on 8th Jul, 2011.

It is neccesary to get the bearing out first.

As you say, it is hard to get at the outer race to tap it, best way I have found is to tap the whole mainshaft slightly the other way to take the gears away from the bearing (not too far or the selector rings may move too far on the hubs sending balls and springs everywhere) then put a hardwood spacer down between the mainshaft and bearing and tap the mainshaft back towards the bearing so the hardwood spacer starts to push the bearing out. You may need to do this twice with increasing thicknesses of spacer.

There are other ways but that is what I have allways found easiest.

EDIT - to make more sense.

Edited by Rod S on 8th Jul, 2011.

Schrödinger's cat - so which one am I ???

Unfortunately Rod, I'v already sent balls and springs EVERYWHERE. All over the garden and i'm never going to find them again. Can that be rectified?

Ok so just use a spacer to push it out against the gears.

I'll give that a go now

A spacer between the gears and the bearing after you have tapped the whole shaft/gears a bit the other way to be able to get a spacer in.

The balls/springs need replacing - easy enough once the mainshaft is out using something like a large jubilee clip the same way a piston ring compressor works, to hold all three in place whilst sliding the sleeve back over the hub - I'm sure most people on here who have actually dismantled a gearbox will admit to losing them at sometime in their life.......

Usual reason is not properly dismantling the selector interlock - if it's not dismantled/defeated correctly the selector forks don't move freely so every time you move the mainshaft the selector sleeves move relative to the hubs exposing the balls/springs.

Schrödinger's cat - so which one am I ???

Got the bugger out at last. Heated up the casing and just kept on bashing with my drift.

Couldn't find a suitable spacer and all the things i tried kept on falling off.

Sadly, the bearing is no more. It got halfway and decided it wouldn't go any further. Drift wasn't working so broke out the pry bar and smashed the thing out the other side.

Now to remove the selector forks and selector and then I can actually crack on with cleaning the box up.

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Jobs a goodun. Not like it took me a week to disassemble. Was my first time though. Gearbox virginity out the way. Stripping her down should be easy next time

Started off caked in terrible flaking, god awful blue paint - which bits had even got into the gear teeth, every single thread and most bearings.

Now totally stripped, 99% of the paint gone and just looking much much nicer. I'm also left with a washing up bowl full of bits in need of a tidy.

Wish me luck for the rebuild.

To be continued on Sunday

Dave

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Can someone link me to the product which will provide me with the necessary ball bearings and springs please. I'v been searching minispares for the last half hour to no avail.

Much appreciated gentlemen

Edit:

Think i'v found the bearings. Are these they?
http://www.minispares.com/Product.aspx?ty=pb&pid=36603

Also think i'v found the springs. Don't say i didnt try :)
http://www.minispares.com/Product.aspx?ty=pb&pid=33146

BUT

Is this the mainshaft bearing i'v ruined? Costly mistake if it is!
http://www.minisport.com/mini-spare-parts/info_AAU1365.html

Edited by carts60 on 9th Jul, 2011.

Yes, yes and possibly.

For the bearing, personally I would fit the genuine RHP one,

http://www.minispares.com/Product.aspx?ty=...id=35662&title=

They are the weak point in the gearbox and, yes, an expensive item to damage.

Schrödinger's cat - so which one am I ???

Best way ive found to do syncro hubs is the place the balls and springs into the inner part, then rest the inner on top of the outer part, then using ET like fingers, push the balls in whilst forcing the inner ring into the outer.

That sounds harder than it looks

Well screw me sideways and call me francis! £48 for that bearing!

Maybe i should have been more careful.

I'v got fairly dextrous fingers so hopefully it shouldn't be too much of a problem to fix.

The bearings are dear,
but IMO you should change them if you disturb them,

It might be worth asking MiniSport if theirs is the RHP one, I doubt it at their price but they may have got a better deal with RHP than MiniSpares so be able to sell them cheaper.

The genuine RHP ones come in an RHP box as well as being marked RHP on the races (the race markings are easy to forge in China, the boxes not so easy.....)

That's not to say all copies/non-genuine parts are automatically bad - you're just taking a gamble when you use them.

Schrödinger's cat - so which one am I ???

I'll shoot them an email now

I used a cable tie to fit the detent balls and springs. There's a picture in the metro van thread somewhere

I put the syncro hub assy in a ziplock food bag when putting them together, cant loose the balls then.