Gearbox Problem

[Suntan Sid]

I was out for a ride on my XL125 earlier, after a 25 mile ride I was 20m from home when I lost all gears apart from first.  I had just been slowing down for a junction and had gone down through all the gears.  There were no grinding/knocking/crunching noises and I could find neutral.

Got it home, dropped the oil and got the clutch cover off to have a look at the shift mechanism.  There were no nasty surprises in the oil so I assume nothing has disintegrated.

With the clutch cover off, when you move the gear change the cam gearshift, (No.6 in the diagram), moves round in both direction but it doesn't stop after 5 changes, it just carries on, same with downshifts, however it doesn't select a gear.
Any thoughts?
My initial thought is that the pin, (No20. on the diagram), has failed.

https://images.cmsnl.com/img/partslists/honda-xl125s-1982-englandmph-shift-drumshift-fork_big00029547e__1400_a9b1.gif
____________________
"Everybody needs money, that's why they call it money!"

[Pete.]

My guess is the index pin - No20 in the diagram - has sheared.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Suntan Sid]

With the engine still in the frame, and not wishing to take the head off, what's the best method of locking the crank so I can get the clutch basket off?
The manual says put it in fourth gear and use the back brake, seeing as I've got no gears at the moment, that's not viable!
____________________
"Everybody needs money, that's why they call it money!"

[Pete.]

Nut gun is the quickest way. If you haven't got access to one of those I look at wedging a small piece of wood in the primary teeth. Go easy though if you snap a tooth you'll need a new basket.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Islander]

Beg steal or borrow an impact wrench - it'll make short work of it.

[Howling TerrorOutOfOffice]

I used the back brake and rags to do the 250.
____________________
Diabolical homemade music Bandcamp and Soundcloud
Singer songwriter, Artist and allround good bloke Listen to Andrew Susan Johnston here
The Harry Turner Project

[Ariel Badger]

Jamming a lump of wood between chain and sprocket does it for me.
____________________
Bikers make great organ donors, get 115 on your licence today.

[Suntan Sid]

Thanks for the suggestions, unfortunately a couple of them require the bike being in gear, which I can't do at the moment, so I guess I'll have to jam something in the primary drive.

Do you reckon I could do it with an impact driver and a hammer?
I can't get hold of a rattle gun.
____________________
"Everybody needs money, that's why they call it money!"

[Ariel Badger]

Jam up the primary drive and try, Other way is to take a plug out and feed rope into the barrel at BDC and use that to lock it all up.
____________________
Bikers make great organ donors, get 115 on your licence today.

[Chuffin Nora]

HTTH...and I could be wrong, but perhaps holding No.12 with a socket, provided that the tension is in the 'doing up' direction.

https://www.bike-parts-honda.com/pieces-honda-detail-37288-1343701A-XL125SC-1982-E__0900-XLS+125.html

(No microfiche for RC)
____________________
There's a fine line between integrity

[skatefreak]

A bit of cardboard, folded up and feed into the primary gears.
Has worked for me every time and seems kind to the gears.
Best of luck.

[mentalboy]

When no rattle gun available I've found the best way is to buy a steel clutch plate for the model in question and weld a piece of bent bar to it then pop it on the end of the basket and Bob's your uncle!

EDIT: For clarity... you hang onto the bar whilst swinging a socket wrench on the nut!!!

[Suntan Sid]

[-]

I bought a mole grip derived tool which holds either the flywheel or the clutch outer basket. Like this...

https://www.ebay.co.uk/itm/Motorcycle-Clutch-Flywheel-Holding-Hand-Tool-Clamp-For-Square-Gear-Hub-Basket-/281772508468?hash=item419af34534:g:alQAAOSwjVVVzHhD

Is the return spring on the selector shaft OK? Does the shaft return to centre when turned by the gear lever?
____________________
TZR250 2MA road, TZR250 1KT road, TZR250 2MA race, TDR250, YZF-750R Boost colours.
Jaguar S Type 3.0 V6 Sport R, VW Transporter T5 GP LWB Shuttle 140ps DSG.

[Teflon-Mike]

If its the generic 'small-honda' clutch:-https://i178.photobucket.com/albums/w269/teflons-torque/Little%20Dreams/LD07%20Eng%20Build/100_0503.jpg
then you'll want the special castle-nut socket, (Honda Service tool, 07716-0020100) to get the pack out before you take the basket off. They are about a tenner on e-bay.

As to locking the shafts, after you've done the tab-washer, shouldn't need to much torque to hold it.. there's another Honda special tool for holding the basket.... a big C-Spanner, if I remember the picture in the manual correctly... if you could find one of them cheap on the bay... else, the strap-type spin on filter wrench for cars, around the outside of the basket MIGHT be just enough purchase; My favourite primary drive 'locking' tool was a thick bit of dural strip.. teeth bit into it and didn't leave saw-dust or threads like wood or rags.

If you have oil-pump, as the Benley engine in pic; then be careful, using the jamming method, there isn't a lot of wiggle room to get owt in between the cogs, behind that brittle ally casing.. and screws holding the pump on are close cousins of the ones on master-cylinder reservoir caps.
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[groovylee]

[Suntan Sid]

[Fizzer Thou]

I used a 2p piece when doing the KTM

https://i666.photobucket.com/albums/vv23/WiNot_Rhencullen/Workshop/Picture006.jpg
____________________
Just talk bikes.What else is there?

Always have a 'Plan B'

[Suntan Sid]

Well, to conclude this sorry episode, it turns out that bolt No.16 had come loose, cheeky little monkey, probably forgot to tighten it during the rebuild.
In my defence there's no torque setting for it in the manual.
Unfortunately I couldn't tighten it with everything else in place, the clutch was just slightly in the way, so had to remove the oil filter and the clutch. I used a piece of 2mm thick aluminium bar to lock everything up to remove and replace the oil filter.
For the clutch I put in it gear, jammed a rag in the sprocket, locked the back break up with a cable tie, (drums), and got Mrs Suntan to sit on the bike, with the front brake on.

https://images.cmsnl.com/img/partslists/honda-xl125s-1982-englandmph-shift-drumshift-fork_big00029547e__1400_a9b1.gif

A PITA really because the gearbox is as sweet as, hardly makes a sound when changing up and down.
Going to get the casing back on in a moment, I'll put everything else, brake lever, kick start, clucth cable etc, back on tomorrow and hopefully remember to refil it with oil!!!!

Thanks for all the help!
____________________
"Everybody needs money, that's why they call it money!"

[Pete.]

If you don't have torque figures just use the standard one for that size of bolt. For M6 that would be 7 foot pounds or 10Nm.

Some threadlock would be a good idea to hold permanently in place.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good