Electra Gearbox Assembly

There’s another fairly recent thread on this, I expect the marks on the selector have not been lines up correctly. You have to take the cover plate off so it can line up. I’ll look for the thread.

I'm pretty sure the selector forks are identical and will only go in one way? 

Thread here: https://www.nortonownersclub.org/node/9762

dan 

Hi Jack

have you discovered this when riding or can you only select 2 when it’s sat on the stand/bench. I ask because these gearboxes are difficult to change by hand without everything spinning. Mine is back together now so I can’t have a fiddle, but I think it’s pretty hard to get it together wrongly if you follow the manual. Although it is fiddly getting the selectors to engage in the plate. I had The two shafts and selector shaft off the inner cover and in the gearbox when I assembled mine. I then put the inner cover on and did everything up.

When you say striker forks I presume you mean the selector forks. They are identical and sit on the shaft facing each other. The gears they slot into have a machined slot and are pretty obvious Looking at the diagram, as you say, it looks like gears 3 and 14. When you assemble the gears for the first time don’t have the detent plunger and spring fitted it makes everything a bit easier. 

Does that help?! 

The selectors are interchangeable but I’m away from my manual at the moment to make a comparison with my photos! 

I see what you mean, I think the problem is that the manual has put the selector shaft in front of the other shafts when it is actually behind. They have used artistic licence to show the gears better. If you move the shaft to the other side the selectors have to rotate and the locating pin moves to the top, if you see what I mean!

Hi Jack,

The clutch centre retaining nut for an Electra is part number 24570 and is cheaply available from the NOC shop.  I have purchased one recently for my late Navigator which shares the same clutch and gearbox mainshaft as an Electra and I can confirm it fits perfectly.   The spares catalogue and Norton manual do not give a thread size but the NOC shop shows it as 9/16" 20 tpi but not what thread form although I found one of the slim NOC Whitworth sockets fitted perfectly.   However, in my limited knowledge I think 9/16" 20 tpi is a British Standard Cycle (BSC) thread form rather than Whitworth.    To be on the safe side I think I would run a 9/16" BSC tap through a new nut first to confirm the thread is correct before risking using a die to restore the difficult and expensive to replace main shaft.   I'm not aware of any metric threads on a Lightweight - they were produced long before metrication.   I hope that helps but proceed with caution, I am no expert on thread forms and my research may be incorrect!!!

Good luck

Nick   

Might be worth looking at a thread file rather than a die - you can get them in different thread forms and they come with a varying number of (8 sizes I think) tpi on each file.  If it’s just the end that’s damaged would be a better bet I think

I had trouble getting a nut to fit, but found the club one solved the problem! 

Dan 

Hi Jack,

Bruce beat me to it, square type thread files have 8 different pitches, 4 at each end and if yours is a cycle thread (BSCy) you just need a UNF file as long as it has 20 TPI, as cycle threads have 60 Deg. thread angle the same as UNF. If you are filing it in situ make sure you stuff rags everywhere to prevent swarfe ingress.

Regards

Richard 

Wise words Bruce, I must get a set of BSC thread files - one of those tools which I suspect you never realise how useful they are until you have a set!

Nick

Jack, I had this with my Jubilee. If the main shaft is not fully home towards the back of the gearbox when you tighten the end plate nuts that somehow locks up the shaft. It is not easy to ensure the shaft is fully home but a good indication is that the end plate should go all the way back with just hand pressure - without the need to tighten the end plate nuts. If the end plate will not go back all the way wiggle the main shaft until it does, pushing the main shaft towards the clutch side as you do that. Worked for me.

Dennis

Sorry, guys - I've come late to this thread - been away from my desk since before Xmas.

The thread started with how to assemble this gearbox, and is there a picture of it outside the gearbox. The timing thing, as explained in the first two pictures is important. There is a mark on the drum (20 on Plate G) as shown on the lower pic above, and a mark on the ratchet plate (27 on Plate G) - visible in the first picture above. Plate G refers to the Parts List.

Instruction 52, 2nd Line (in the Electra Manual) tells you to line these up.

If you are using the Twins manual, then on page 45 "The Footchange assembly" explains

The two selector forks (21 on Plate G) are identical. The two grooves they sit in can be plainly seen.