I took my '64 Jubilee for a short test ride today after fitting a new battery. I could only select first and a second gear. I was sure I had checked that all gears selected before I put the engine back in the frame but perhaps I did not.
Looks like a gearbox strip down is required but before I do that does anyone know why only two gears are selectable? I come up against a hard stop when trying to move the gear lever to third gear.
I seem to remember I had several attempts to put the gearbox back together and on the last attempt things just slipped into place. I don't know why it worked that time and not before.
Lastly, do I have to dismantle the clutch side to free up the gearbox main shaft or can the main shaft stay in place while I take apart the gearbox from the kickstart side?
Have you tried with the engine running? Also check if your gear lever is fouling anything (can’t remember if it can) but it’s a common issue on other makes.
Not sure how much you can dismantle without undoing the clutch, but you should be able to see what is going wrong.
I’m stripping mine shortly with the engine in the frame to replace the sleeve gear, so may be able to offer further comment!
Dan, thanks for the suggestions, Yes I tried with the engine running and I checked the gear lever was not fouling on anything.
I am going to take off the gearbox cover without dismantling the clutch side to see if there is anything obvious as it is such a pain to strip the clutch side. I may still have to remove the clutch at some point.
There seems to be no further downward movement of the lever after second gear so it might be the selector is in the wrong place.
I'll give an update when I have some news.
I’ve had my early gearbox apart a few times it’s pretty much impossible to put that together incorrectly, I’ve only had the front cover of the late type (vainly trying to fix oil leaks!) but will be stripping it to fit a new sleeve gear as soon as I’ve finished timing the ES2. I can’t remember if you can put the selector in the wrong position? I’ll post the extracts from my original manual
Dan, many thanks (again)!
Not got around to taking the gearbox apart yet, enjoyed doing other things in the good weather.
I have the manual as an .PDF but thanks for the images anyway.
The first thing I will check is the alignment of the foot-change ratchet alignment mark with the mark on the small pinion. If that is correct the other possibility is one of the 3rd or 4th gears may be reversed stopping the selector fork from engaging/moving the gear but I think this is unlikely.
I found that the footchange selector ratchet was not aligned correctly with the small pinion on the selector shaft, hence the 'lost gears'.
The manual specifies aligning the mark on the selector with the mark on the pinion. Sounds easy but the first issue was identifying the mark on the selector as it is partly obscured by a locating plate and looked at first glance like a manufacturing blemish! Secondly, the pinion mark was in fact two punch marked 'N's, so I take it that the pinion tooth between the Ns is the locating one for neutral. If this was not obtuse, then not being able to see either mark on assembly was a real problem. The parts are behind the gear cover plate on assembly.
My solution was to find the position of the selector relative to the pinion without the cover plate in place, take the selector plate off without moving it, mark the two peaks of the pinion gear that mesh with the selector (those either side of gear trough marked by the Ns) using correction fluid ('liquid paper'), refit the selector and loosely fit the end plate, check the alignment by peering through a hole in the end plate using a torch to see if the mark on the selector is aligned between the marked teeth of the pinion.
Before I sound too smug, having assembled fully the gearbox and I can now select four gears but there is a mysterious neutral beyond fourth gear and first is hard to select. I may still be one tooth out on the small pinion !!
I will do a road test before I decide if I need another go at aligning the selector.
The manual seems light on advice.
I used to tell friends that Haynes manuals were similarly challenged. They follow an inverse law. You get 20 paragraphs on how to change a bulb and only a few lines for a difficult task usually starting with : "First remove the engine.....".
I’ll be doing mine next week, I’ll let you know how I get on! Sounds like you are on the right track.
Dan, many thanks. I am interested particularly in the alignment mark on the selector plate as I am still not convinced that what I am seeing is the correct mark. The pinion is marked clearly so identifying the position of the selector plate is critical to success.
I have decided to strip the gearbox again to have one more go.
Dan, I took some photos of the pinion and gear selector alignment marks. The selector plate mark is obscured by the locating plate so I have moved that to one side. The 'mark' appears to coincide with the hole in the selector plate. This mark is hidden when the locating plate is in position!
I am hoping you can confirm that you have the same alignment mark on your selector.
Even if the alignment marks are correct there sees to be some potential on assembly to get the alignment wrong resulting in too few gears or at the other extreme, a false neutral after 4th gear.
Dan, having just assembled my gearbox wrongly again I have had a eureka moment. I did not realise that the selector alignment plate is detachable from the gear lever shaft! I should have looked more closely at the diagram you posted.
No wonder I could not see the alignment marks. By disassembling the selector mechanism I should be able to offer up the selector and align it with the pinion before fitting the locator plate that obscured the alignment marks previously. This was not obvious before as the shaft (28 in the diagram) seems firmly fixed in the gear lever shaft (32). I will have to investigate how to get them apart.
Hi Dennis, nothing surprises me anymore!
I'll not be stripping mine until next week now, I'm showing mine at the local fete and don't want it in bits, as it is there's nothing inside the chain case! I want to replace the sleeve gear so it will be a complete strip of the gear box and I might as well do the bearings while I'm in there.
Thanks anyway and good luck with your repairs.
After three more goes yesterday I might have set up the gear selector correctly.
As I suspected, fitting the selector shaft without the gear change ratchet does allow me to see the 'alignment' marks, the problem is that the pinion marks (the two N's) still only give an approximate alignment; one of three possible gear teeth. The alignment has to be exact otherwise the selector won't work properly. A single mark on the pinion would have been much better.
Frustratingly, you can only test the selector alignment with the gearbox assembled fully (without oil). If the alignment is wrong it is a full stripdown including mainshaft nut and tab washer.
It looks like the top 'N' mark, at about 4 o'clock, is the correct one to align with the selector mark, with the lower 'N' at about 5 'o clock.
No wonder I thought the selector shaft was part of the gear change assembly. I had to hold the gear change lever spline is a vice (lead jaw protectors) and drift the centre shaft out using a bolt screwed into where the gear indicator goes. The shaft has two o-rings as oil seals and they are a tight fit even when lubricated. This causes a problem on reassembly. When the selector shaft is in place in the gearbox the gear lever shaft has the fitted over it. I had to tap the gear lever shaft spline on the front face gently until the selector shaft protruded past the spline end; only then could I get the outer casing on.
Lastly, I found fitting the kick start return spring before fitting the clutch lifter and specifically the large circlip made fitting the spring easier as it does not foul the circlip. You might want to withdraw the clutch cable entirely from the casing as it can easily stop the inner plate going back in place.
DThanks for that Dennis, I’ve just stripped mine and wish I hadn’t!
Anyone got any spare late selector forks?! - Looks to have been brazed, to be fair I had all four gears but a bit of a whine and rather too many metal flakes in the bottom of the box! Mind you this is the engine that had a wooden cam chain adjuster!
Ouch, what a mess. I hope you locate a spare.
I now have four gears but the change is clunky. I used heavy grease to lubricate that gear selector shaft and that was a mistake. I thought it would help the two oil seal o-rings do their job but it just gummed up the shaft. The shaft and seals do require lubrication but thin silicone grease might have been better.
Really sorry to see that Dan, although not listed in their spares catalogue Norvil might just be able to help. Do you know of anywhere else that can provide late Lightweight gearbox and clutch spares? That said I wonder if Hamlins at Bridgewater could 'recondition' your damaged ones? I would welcome any feed back if you go down that route - you never know what the future holds with a Lightweight! is your Navigator on the road? If so do you fancy meeting up on the bikes for a coffee? My Navigator is behaving at the moment so always taking it for a run!
Sadly the Navi is still only partially assembled, and the Jub gearbox is in bits! If I can’t get any selectors quickly I may accelerate the assembly! But am up for a coffee if I can get anything running! the ES2 trials just needs timing. At least my scrambles bikes are behaving for the moment! Remind me where you live?!
Near Crewkerne, I seem to remember you saying you aren't far away. Good luck with the parts search - much as I prefer the later gearbox spares supply is a real worry. As for the ES2 - there is nothing quite like a morning spent grappling with a timing disc, feeler gauge and a cigarette paper setting up the timing....at least it is a single!
Can you provide me with the part numbers you need?
With the numbers I will check all my sources here in Northern California.
That’s very kind if you it’s 048185, but hang fire for a couple of days, I may have found one over here.
Any progress with the gearbox yet?
Planning to strip mine again in the next two weeks and I wondered how you got on.
Yes and no! I’ve stripped it, put in new selector forks and fitted a new sleeve gear bearing and reamed the new sleeve gear bushes to fit the main shaft, I put the gearbox back together which was fairly straight forward. The splined gear change shaft comes apart nicely on mine. Looking at the selector drum in the gearbox I can clearly see the N for neutral and the tooth directly above it has a small notch in it to line up with the selector mechanism. See below:
This means there is only tooth to line the selector mech with. I marked the tooth with chalk to make it easier.
I then put it together with just the selector mech in place and held the cover and I had 4 gears and neutral - result! I then set about replacing the layshaft ball race in the inner cover, I heated the cover and tapped it in but it seized solid and would run smoothly after I’d cooled it down so I’ve ordered 2 more from simply bearings to try again!
My other problem is the outer cover, I have fitted a square seal in the slot for the gear change shaft but the slot for the kickstart has been butchered so I think I’ll have the case machined to take a normal oil seal - also ordered from simply bearings.
So I'm closer but not quite there yet, I need to get it finished as I have another project to start!
My only other worry is my kickstart pawl, that’s badly worn, there’s one for sale for a Triumph on the Fecked site that might order to see if it fits ( it’s only £3!)
Well done Dan, it shows how rose tinted spectacles take over with age, I can't remember battling with that when I rebuilt my late Jub' back in the 70s! I expect you already know this but just in case you have missed it the NOC shop has late gearbox kick start pawls for sale for £5 - might save disappointment in the long run! Good luck with getting it finished and keep us posted - really helpful stuff!
Glad to hear that you are making progress despite some problems.
Bizarrely, I have TWO N's marked on the small pinion gear so you can understand why I have had problems.
Your photo helps a lot as I can now make a good guess at which mark to line up with.
I am also wondering how good the selector locator in the base of the gearbox is (24 in the diagram you provided above)? It could be a weak spring or a worn pin, I have a new spring but I can't seem to find a new pin for sale.
Thanks Nicholas, I’ll order one the triumph one was a bit short! I couldn’t see the pawl in the NOC shop ... must try harder!
My pin is chisel shaped rather than pointed as it shows in the picture. Have you tried Russel motors? Some parts are also shared with the Franny Barnett cruiser .... I must get a parts book to see what is!
I have not tried Russel motors so thanks for that tip.
Also, I can't seem to identify a part number for the plunger (24 in your diagram above) in the NOC spares list.
There is a plunger on Ebay at the moment described as: "NOS camplate index plunger Norton Commando, AJS, Matchless, AMC, No# 04-0034."
Not sure if that would fit.
Having looked up the Cam Drum Plunger (item 24 above) in my Norton Spare Parts list - the part number is: 048177. I have used Russell Motors who although wonderfully old fashioned in the way they do business (no email or ability to order on line) are absolutely brilliant on the phone and in the way they treat their customers. You will probably have to write to them with your order and pay by cheque - that's what I did but they turned it round in a couple of days! Good luck and let us know how you get on.
Hi again Dennis,
I have just been ordering some parts for my Navigator from Norvil and checked their on line catelogue to see if they listed the cam drum plunger which they don't. However, they list one that the catalogue says fits 'most bikes', including the Lightweight twins - it is listed as Plunger Cam Plate Fits Most Bikes - the part number is 040034 and it is £7:50 plus of course the VAT. It might be worth trying if Russell's cant help.
Thanks for both replies and the information.
Interestingly, the plunger listed in NOC spares for the Commando is '04-0034', most likely the same as Norvil's '040034' and it is only about a fiver!
Worth risking that to see if it fits.
That woukld get my vote Dennis and at that price it has to be worth a try! Let us know if it fits, you never know when one might be wanted!
My guess is that it won’t fit, the amc box plunger is pointed, I think the lightweight one is chisel ended to fit in the selector drum slots, but then it’s possible that my part is wrong!
I have my Jubilee gearbox sorted at last.
Thanks to the NOC spares scheme I bought a new plunger spring and the other springs used in the gear change mechanism.
I was surprised to see that the old plunger spring was only two thirds the length of the new one and was much weaker. The spring that returns the gear lever to its central position was also worn and weak.
The selector action is much tighter now though I still get a false neutral between 3rd and 4th gear but I can live with that.
As Dan suggested the plunger for the commando did not fit; it is the same size but is not chisel shaped at the business end. My old plunger was not too worn and the new spring made all the difference.
Dan's pictures helped me greatly to set the position of the gear change relative to the small pinion.