Hi all. Went for a short run up to the store today shifted into first the gear change lever lifted up to near a 45 degree angle way out of position. I could shift into 2nd and 3rd but no 4th lever had no more action. By the time I headed back home I could only shift in and out of 1st and 2nd no 3rd or 4th neutral ok lever was at this weird angle. I opened up the outer and then inner cover but can see no apparent reason for this kind of behavior.Everything looks ok no broken spring however when changing the gears with the knuckle end of quadrant transmission seems rough, sloppy and easy to jam. Any ideas would certainly be welcomed 4000 miles on a recent rebuild. 69 750 roadster
gear box
- Thread starter DOXFORD
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It sounds as if there is a tooth missing from the quadrant or cam plate. I've never heard of it but can't imagine what else could cause this loss of indexing on an assembled box.
If you've got the outer cover off, you can remove everything apart from the mainshaft and sleeve gear with the primary drive still intact, so it should be possible to see what's damaged
If you've got the outer cover off, you can remove everything apart from the mainshaft and sleeve gear with the primary drive still intact, so it should be possible to see what's damaged
Doxford,
I recently suffered from the same problem, a distorted tooth on the camplate spindle gear. Try the following:
Remove the inner cover and the layshaft and all removable gears, leaving only the sleeve gear and 4th lay. Lower the index plunger until it still indicates but does not interfere with the motion of the cam plate. Remove the camplate spindle bolt on the outside of the gearcase and slide the camplate away from the quadrant until it rests against the sleeve gear. The camplate and quadrant can now be independently rotated on their respective spindles but CANNOT BE REMOVED due to the interference with the sleeve gear. You can exercise both pieces sufficiently to be able to tell which part is preventing smooth meshing, and whether these two parts are the ones causing your problem. While diagnosis is straightfoward, repair is not. In order to replace the camplate and/or quadrant, the sleeve gear must be removed, which means the sprocket nut must be removed, which means the inner primary cover must be removed, which means the outer primary cover and ALL of the primary components must be removed. You will wind up having to stip down the entire drive train excepting the engine itself. The VERY small consolation in all of this is that the camplate/spindle can be had for $60 and is widely carried. The quadrant is a bit more and only a few suppliers (Old Britts, e.g.) carry it. I understand that some brit marques foresaw this problem and cut away the backside of the camplate, allowing for its removal. Alas, not Norton.
If there is anyone out there in Norton-land who can think of some other method of replacing the camplate, let us know. This is a gruesome job.
I recently suffered from the same problem, a distorted tooth on the camplate spindle gear. Try the following:
Remove the inner cover and the layshaft and all removable gears, leaving only the sleeve gear and 4th lay. Lower the index plunger until it still indicates but does not interfere with the motion of the cam plate. Remove the camplate spindle bolt on the outside of the gearcase and slide the camplate away from the quadrant until it rests against the sleeve gear. The camplate and quadrant can now be independently rotated on their respective spindles but CANNOT BE REMOVED due to the interference with the sleeve gear. You can exercise both pieces sufficiently to be able to tell which part is preventing smooth meshing, and whether these two parts are the ones causing your problem. While diagnosis is straightfoward, repair is not. In order to replace the camplate and/or quadrant, the sleeve gear must be removed, which means the sprocket nut must be removed, which means the inner primary cover must be removed, which means the outer primary cover and ALL of the primary components must be removed. You will wind up having to stip down the entire drive train excepting the engine itself. The VERY small consolation in all of this is that the camplate/spindle can be had for $60 and is widely carried. The quadrant is a bit more and only a few suppliers (Old Britts, e.g.) carry it. I understand that some brit marques foresaw this problem and cut away the backside of the camplate, allowing for its removal. Alas, not Norton.
If there is anyone out there in Norton-land who can think of some other method of replacing the camplate, let us know. This is a gruesome job.
Hi all just to let you know my findings with gear change problems. I have found what is causing the issue however I am not sure why or how to correct what the problem is. I hope I can explain it correctly. recap: the gear change lever had moved to an unusual higher position than normal 3rd and 4th gear not working. What I have discovered to cause this condition is the rachet plate assembly has moved out of position. I find that with a bit of effort I can hold the gear change lever and move the rachet assembly independently without the gear change lever moving as well. This seems wrong. I have repositioned the rachet assembly and can now select all the gears. What I don't know is how to stop this from happening again. What secures the rachet assembly to the splined shaft the gear lever slides on. I'm sure they should both move at the same time. This is where the problem is and most likely will happen again. I am unsure how to prevent it. Is it a press fit? Is there a clip or spring-clip I don't see it. I hope I have explained the issue correctly thanks for any help.
Doxford
Doxford
DOXFORD said:
pics might help
Ron L
VIP MEMBER
The ratchet assembly slips inside the pawl carrier which is one piece with the splined shaft on which the gear lever rides. The long thin spring allows the ratchet pawl to rotate enought to engage the gearshift pawl lift the quadrant, thus rotating the camplate inside the transmission. Releasing pressure on the shifter allows the ratchet pawl to return to a neutral position for the next change (up or down).
When you say the ratchet plate assembly has moved out of position, I don't follow. The ratchet plate can only rotate up or down as it pivots inside the shift pawl carrier and a bushing in the inner cover.
I would closely inspect both the large spring on the pawl carrier and the slender ratchet spring. These often corrode, weaken and break.
I believe that the shaft that the shifter mates with is pressed into the pawl carrier assembly (part # 04-0110), if this was an under spec press fit than a few years and a ton of heat cycles may be allowing the two parts to get loose with heat. If I am correct than you can fix this by drilling in a key way between the two parts, thread the hole fill the hole with green loctite, drive in a bolt, cut of the bolt flush with the surface and grind/polish until there is very little evidence of your fix.
Or you can buy a new piece.
Best wishes,
RS
Or you can buy a new piece.
Best wishes,
RS
I am confused here, you say the ratchet assembly can be moved without the gear lever moving, that is possible with the gearshift pawl in certain positions, the problem must lie with the gearchange pawl. As a picture paints a thousand words look at this from oldbritts http://www.oldbritts.com/gearbox_info.html
does this look like your gearbox pawl and ratchet? with just these parts assembled you should be able to move the ratchet plate up and down using the gear lever with the gear lever returning to the standard position. If not check all these parts (compare to parts list/pictures and the oldbritts page if all ok then pop the outer cover back and try the gears again. (Check the gearchange pawl circlip is there). One last thing the ratchet assembly is not 'secured' to the gear lever shaft it is free to rotate around it.
plj850 you are absolutely correct : for myself it has been about 20 some odd years since I have had the gear box apart and I am a wee bit not remembering how the parts should move inside the outer cover. My mistake thinking the rachet assembly should be secure in place. After further disassembly and examination I see that the rachet assembly is indeed a push in part with a small o-ring on the rachet shaft. The rachet assembly is able to rotate or float feely in this position. In my case the rachet assembly was stuck/tight and not free to operate correctly which inturn contributed to gear selection failure.The o-ring broke interfered with the free movement of the rachet and caused it not to move to its proper location. I replaced 0-ring boxed it up went out for a test drive and I am back in the saddle again. I thank you all very much for your imput this is such a great form and certainly a valuable informative tool in helping to keep us NORTON riders on the road tks
Sorry to bring this thread up again, but I've only just come across it. It seems to me that the ratchet assembly should not "float", but is held firmly in place by the bolt & gear indicator pointer on the outboard end of the shaft, or were you saying that the ratchet shaft was in effect siezed inside the gear lever shaft?
Terry
Terry
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