My first Matchless is here!!

[Mick D]

What else should I be checking for in here before I start to reassemble when the gaskets arrive?

Hi

That box looks fine, do a dummy re-assemble and see if you can find all of the gears - spinning the main shaft from the clutch hub will help the dogs align.

John's right, you don't need to take the box out of the frame to complete assembly from this state but if the box is coming out anyway, it's much easier to assemble with the shafts vertical.

With regard to replacing the seals, you're in a bit of a poor position, the GB looks like it may have had a recent overhaul but with no oil in it you can't determine if the seals are good. I'd replace them all as a matter of course but if you're on a budget, have a good look at all of them and make your choice. The output bearing seal as that is the most difficult to fix in situ, the kick start, gear change and indicator seal are all in the outer cover and easy in situ.

Regards Mick

[markwhitelock]

I have placed an order with the club shop and included 1x #27-7-4 - PWB4.OIL SEAL G/CHANGE QUADRANT. B52 variations = £1.80
1x #27-4-2 - OIL SEAL; CAM SPINDLE IN B52 variations = £1.65 1x #27-7-5 - 11206825.OIL SEAL;KICKSTART SPINDLE variations = £2.17

Have I got the seal for the gear indicator there? I couldn't see any others on the parts diagram.

I didn't order the output seal 😩

[Mick D]

Have I got the seal for the gear indicator there? I couldn't see any others on the parts diagram.

Hi

Yes, that's the cam spindle seal - just my bad description

Do you intend to strip the engine? If so you'll have plenty of time to replace the output bearing seal, and it can be done with the gearbox assembled so won't hold up progress on that.

Regards Mick

[Pharisee]

If you have a 1/4" BSW tap, I'd run it into the threads just to clear the muck out and make sure the screws go fully home. It may be an optical illusion but it look like at least one of your threads has a Helicoil insert. If they've been installed correctly, it's not a cause for concern. Apart from that, it all looks good!
As spookefoote says, for the few shillings they cost, the three oil seals in the outer cover (kickstart shaft, gearshift shaft and gear indicator/selector drum shaft) ought to be changed. They are usually, hard and cracked at best or missing completely at worst. You dont want oil running down the casing of your newly rebuilt grearbox.

[markwhitelock]

Outer seals are all ordered.

Will this tap work..



Which other threads are the same size?

[Mick D]

Hi

No, that tap is a 1st or taper tap, you need a plug tap, one without a taper ground onto it. However if you have a compressor you can flood the holes with brake cleaner or similar and blast the debris out - more efficient than trying to dig gunge out with a tap. It won't restore a thread but it wil allow you to assess the situation first.

As I said before, your box looks like it's been recently overhauled, shine a torch down the holes and if they look OK put the cover in place and see if the screws nip up easily, if OK don't worry.

Regards Mick

[Pharisee]

Outer seals are all ordered.

Will this tap work..

Yes it will but ideally, I'd use a plug tap rather than the tapered tap as you only want to clean any dirt out, not actually cut a new thread.
For the same reason, a carbon steel (CS) tap will be plenty good enough. You don't need the more expensive high speed steel (HSS) option.
Tracy Tools will flog you one for a couple of our fine British quids!

https://www.tracytools.com/taps-and-die ... 20-tpi-bsw

EDIT.... sorry, Mick D replied whilst I was typing my reply!!

[JEAN-NOEL]

I agree with "Pharisee".

[markwhitelock]

Thanks for the input Gents

I ordered a rubber seal for my chain case as mine was missing, I noticed on the club shop that a gasket is also listed. The parts diagram for my bike doesn't mention it, is this something that later models had? Can it be retrofitted on earlier bikes?

[Mick D]

Hi

Give us a chance - what's the part number?

Regards Mick