My first Matchless is here!!

[SPRIDDLER]

Welcome, Mark. I've been touring France for the past ten days so have missed out on all the fun.
From a quick scan of this thread I haven't seen that you have been given a ref to the several comprehensive and illustrated articles on B52 g/box o/hauling in the archives. Maybe you've already found it, but if not........
Have a look here under 'Transmisson' then choose 'AMC'.
http://archives.jampot.dk/technical/

[Pharisee]

GB-Box.jpg

Your last photo showed the mainshaft with three gears on it. The middle gear of the three in the photo is the one moved by the selector fork. That gear should very definitely slide on the mainshaft. The 'dogs' on the end nearest the clutch engage (or disengage) with with the ouput sleeve gear.

Edit.. Sorry.. Photo shows four gears.. the third one down is the one that moves. The first three should all slide off the mainshaft (with the selector fork/rod)

[markwhitelock]

Ok. So rather worrying that one doesn't budge then!

[Pharisee]

It's almost certainly the first, small gear in your photo that is the problem. That locates on splines on the mainshaft. It's not supposed to slide along the shaft once the gearbox has been assembled and if it's been in position for 60 years, it might be a bit reluctant to move but is should pull off. The second gear down is free to rotate on the shaft. If you can spin it on the shaft, it will slide off once the first gear has been removed. The third gear down should be a sliding fit on the shaft splines as it is this gear that the selector fork moves backwards and forwards. You can't remove the fourth gear until the clutch assembly and final drive sprocket have been removed.

[markwhitelock]

No, the first small gear slides off easily, it is the second larger one behind that does not budge.

I can pull it forward about 1mm or so but then it jams, it feel like it is being stopped by something yet there is nothing there.... I will try again tomorrow.

[Pharisee]

The second gear should be free to spin on the plain section of the main shaft. With the first little gear off the mainshaft there should be nothing to stop the larger second gear from being removed... unless the broze bush in it's centre has seized onto the mainshaft. If you can't pull it off, then I assume that you can't turn it on the mainshaft either?

[Mick D]

Hi

The gear that is currently stuck rotates on a bronze bush which sits on the main shaft where indicated:

Main Shaft.png

The bush should be free to rotate on the main shaft AND within the gear - so you should be able to rotate the gear on the shaft , give it a try.

The spline to the right of the arrow retains the upper gear in your photo, (this is the main shaft 1st gear) - you say this gear slides off, this is as it should be.

In service the 1st gear contacting the shoulder which retains it in the correct position on the main shaft raises a slight burr which can interfere with the smooth sliding of the bronze bush when trying to remove the second gear, (I'm pretty sure this is what's happening with your gearbox), hence my recommendation to try pulling the second gear off with a puller and my advice that it should slide off easily, (but maybe not with finger pressure).

If you don't have a suitable puller you are going to have to remove the clutch hub and withdraw the main shaft complete with second gear, third gear, the selector fork and shaft. This is now problematic for you as you have no means to secure the clutch hub against rotation, I suggest you acquire the use of clutch spragging tool similar to the AMC one in the photo below - hopefully someone local to you will offer a loan.

Clutch Spragg.png

Regards Mick

[markwhitelock]

Thank you guys, if there is no reason why that gear should be stuck I will look at what I can do, I was being very cautious about forcing anything!

[Mick D]

Hi

With regard to the dynamo, it's pretty easy to check.

Remove it from the bike - does it spin freely using finger pressure? (there should be some resistance felt from the brushes but not a lot).

Remove the end cover and the brushes, Are the brushes in good order and their conductors intact?

Spin the armature again, it should be very free now, there should be little or no end float in the armature. If it rumbles the bearings will need to be replaced.

Have a look at the commutator, it should be smooth and polished by the brushes, if it's mucky give it a wipe with a rag or tissue soaked sparingly in brake cleaner.

Reassemble the brushes and re-connect them electrically.

Put the leads of a multimeter set to DC voltage into the D and F sockets, (it doesn't matter which lead goes where), and spin the dynamo with you fingers, (may help you grip the shaft if you fit a nut), the multimeter should register a small voltage, (around 1 volt is fine). This proves the armature windings and that the dynamo will more than likely function, if you don't see a voltage the armature will most likely need to be rewound.

Post back with the results of the above if you're unsure how to proceed.

Regards Mick

[Group Leader]

There is some very useful and relevant information from, amongst others, Albert and Groily on my dynamo saga thread:

http://www.jampot.com/forum/viewtopic.p ... 6&start=10

In essence, you sould be able to "motor" the dynamo with the aid of the battery to prove that both the field and armature are intact and correctly wired.

Alan