Shifting issues update…>

1973 850 roadster with 8400 miles. Posted a week or so ago about a shifting issue. Symptom is that upshifts go into a false neutral, all downshifts hit gears properly. The shift from 1st to 2nd will wind up in neutral, when I follow with a quick downshift I'm in second. Same thing 3rd to 4th, false neutral and then a downshift and I'm in 3rd. 3rd to 2nd to 1st are no problem. I picked up three springs from OldBritts, the two springs for the gearshift ratchet mechanism and the detent plunger spring if I wind up going in that far. I pulled the outer gearbox cover and inspected the ratchet mechanism. The two spring arms were contacting the pawl when centered. The bottom spring was covered in crud. I replaced both springs putting enough bend in the top spring to provide a small bit of clearance from the pawl. New gasket, refit all and filled the gearbox back up. Took it out this morning and I've got no difference in the symptoms. It will hit an upshift here & there, maybe a few times in ten shifts. If I've got to do a gearbox overhaul I'll probably hold it off for a winter project and ride the Bonneville for the summer. The good news is that the bike is running really well. Kicks over first try, idles nicely, good plug color and it really pulls like a bear. I'm running a Trispark and Amal premiers. Big difference between the Norton and the Triumph when the throttle is cranked. The Triumph accelerates, the Norton jumps. Thanks in advance. Tom https://picasaweb.google.com/1001603808 ... 50Commando

Well at least ya fixed the superficial things but rarely do stop gap short cuts work out efficiently on Cdo's as just to the bottom again then working back out fixing what ever from there. Expect worn bushes and maybe smeared shifter dog faces as the slick snicking hang ups. Of course could end up being primary drive issue too.

Don't wait to fix it just jump into it, it's not a hard job and its probly only a minor thing that is wrong with it, maybe a slector problem or the springs need to be sprang better, even with worn bushes it still should pick up the gears when changing up or down and as Steve said it could be a clutch problem or primary chain to tight, something simple, fix it while its freash in your mind.

As well don't over fill your gear box as that can cause problems as well.

Ashley

Then again we may all learn some thing if it turns out to be some thing none of us ever encountered before.

ommief said:

It will hit an upshift here & there, maybe a few times in ten shifts. If I've got to do a gearbox overhaul I'll probably hold it off for a winter project and ride the Bonneville for the summer.

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When it misses the shift, if all you feel when you move the lever is resistance from the return spring, then the problem is likely to be something to do with the ratchet mechanism.

Each time the lever moves, either up or down, the pawl should engage the ratchet plate.
http://www.oldbritts.com/gearbox_a.html


Also check if the quadrant is 'timed' to the camplate correctly?

L.A.B. said:

ommief said:

It will hit an upshift here & there, maybe a few times in ten shifts. If I've got to do a gearbox overhaul I'll probably hold it off for a winter project and ride the Bonneville for the summer.

Click to expand...

When it misses the shift, if all you feel when you move the lever is resistance from the return spring, then the problem is likely to be something to do with the ratchet mechanism.

Each time the lever moves, either up or down, the pawl should engage the ratchet plate.
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Click to expand...

Les
Tell me to go start another topic (as you often do) if I am interfering in here, but as you are an owner of the "only Commando worth discussing" I'd like to ask you a question.

When stationary, moving from 1st up (note all you second rate citizens, I said UP) to neutral can be difficult. Quite some resistance and often arrive in 2nd instead, then snicking back down, end up back in 1st again. Other times it is a piece of piss, like cutting through melted butter. Sometimes you arrive in neutral without the green light at all. Imagine that, being in neutral without a green light on, how archaic!! I figure this could just be a contact cleaning issue but I cannot accept sitting at the lights without my green light on, anymore than I can imagine being on a Commando without a green start button.

Do you experience any of this? I mean the issue, not my mental problem. The resistance finding neutral from 1st is probably my main issue. It can be resolved often by easing out the clutch whilst selecting neutral, but not always.



Phil

phil yates said:

When stationary, moving from 1st up (note all you second rate citizens, I said UP) to neutral can be difficult. Quite some resistance and often arrive in 2nd instead, then snicking back down, end up back in 1st again. Other times it is a piece of piss, like cutting through butter. Sometimes you arrive in neutral without the green light at all. Imagine that, being in neutral without a green light on, how archaic!! I figure this could just be a contact cleaning issue but I cannot accept sitting at the lights without my green light on, anymore than I can imagine being on a Commando without a green start button.

Do you experience any of this? I mean the issue, not my mental problem. The resistance finding neutral from 1st is probably my main issue. It can be resolved often by easing out the clutch whilst selecting neutral, but not always.

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I do sometimes find that selecting neutral from 1st can be, let's say, 'tricky', that's why I try to select neutral before coming to a complete halt, whenever possible.
Clutch drag, accumulated slop in the Mk3 cross-shaft mechanism and the remoteness of the shift mechanism from the gear pedal, the fact that the cross-over mechanism (including the actual ratchet mechanism itself) is slightly out of alignment with the shift quadrant must all contribute to what can only be described as an occasionally 'less-than-precise' shift movement.

I don't recall ever having problems with the neutral light (switch).

L.A.B. said:

phil yates said:

When stationary, moving from 1st up (note all you second rate citizens, I said UP) to neutral can be difficult. Quite some resistance and often arrive in 2nd instead, then snicking back down, end up back in 1st again. Other times it is a piece of piss, like cutting through butter. Sometimes you arrive in neutral without the green light at all. Imagine that, being in neutral without a green light on, how archaic!! I figure this could just be a contact cleaning issue but I cannot accept sitting at the lights without my green light on, anymore than I can imagine being on a Commando without a green start button.

Do you experience any of this? I mean the issue, not my mental problem. The resistance finding neutral from 1st is probably my main issue. It can be resolved often by easing out the clutch whilst selecting neutral, but not always.

Click to expand...

I do sometimes find that selecting neutral from 1st can be, let's say, 'tricky', that's why I try to select neutral before coming to a complete halt, whenever possible.
Clutch drag, accumulated slop in the Mk3 cross-shaft mechanism and the remoteness of the shift mechanism from the gear pedal, the fact that the cross-over mechanism (including the actual ratchet mechanism itself) is slightly out of alignment with the shift quadrant must all contribute to what can only be described as an occasionally 'less-than-precise' shift movement.

I don't recall ever having problems with the neutral light (switch).

Click to expand...

Same same re selection of neutral prior to stopping. Works perfectly but not always possible when hurtling into carport from pub at 60mph. No accumulated slop in cross-over mechanism that I can detect. All was rebuilt only 500 miles back, but the rest of your comments make sense. I was hoping you would tell me to start another topic. I was going to name it "Another Topic". I don't like discussing these issues in front of the boys. A bit like discussing family issues in front of the children.

Thanks Les
Phil

just mentioning to save others my frustrations on pawl spring adjusting that about only thing that matters is the section of legs the pawl swings by be parallel so trying to match the manual clearance mainly just throws ya back to trying to get the springing back legs re-spung back parallel again. When moving AMC should shift up/dn in and out of N each time toe touched with just a bit less toe action distance to snick N. If stopped I snick to 2nd then timid tap to about every time hit N. Getting to point of enjoying a fully fettered Commando is worth always aspiring too as any thing short of that is such an annoyance tempting to stick back in the barn.

hobot said:

just mentioning to save others my frustrations on pawl spring adjusting that about only thing that matters is the section of legs the pawl swings by be parallel so trying to match the manual clearance mainly just throws ya back to trying to get the springing back legs re-spung back parallel again. When moving AMC should shift up/dn in and out of N each time toe touched with just a bit less toe action distance to snick N. If stopped I snick to 2nd then timid tap to about every time hit N. Getting to point of enjoying a fully fettered Commando is worth always aspiring too as any thing short of that is such an annoyance tempting to stick back in the barn.

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Fully fettered hobot,
You will never break your chains till moving onto a MkIII. Just accept it.
Yes I know the trick you speak of, into 2nd then back to neutral when necessary works well with the AMC gearbox. Just doesn't sometimes work as well with the MkIII, there is just not quite the same "feel" there. But it operates well in every other sense. I blame American regs for causing the swap in the first place. I couldn't care if the gear change was on the back seat. But mambi pambi pro Japo influence said put it on the left.

Phil

hehe, Philup sorta of like I was told on moving to Texas, never ask someone where there are from so not to embarrass them if not from Texas. You are either fibbing about daily E-start use or have an exceptional robust spragthrope gizmo to brag on. Personally I'm concerned the TTI tranny will feel like other modern manual mc shifting so another reason for its wide ratio's if I miss AMC thoughtless sweetness just to take some rare full Peel power pulls. Don't miss checking shaft straightness like I over looked first time or two. I ain't hardly stopped fixing and wrenching on stuff - just to recover life's vitals - so ain't done much with cycles to matter. Oh yeah once sealing up all fixed up might consider thick grease or paint on outer cover parts above oil level condensation zone, with the next guy in mind.

hobot said:

hehe, Philup sorta of like I was told on moving to Texas, never ask someone where there are from so not to embarrass them if not from Texas. You are either fibbing about daily E-start use or have an exceptional robust spragthrope gizmo to brag on. Personally I'm concerned the TTI tranny will feel like other modern manual mc shifting so another reason for its wide ratio's if I miss AMC thoughtless sweetness just to take some rare full Peel power pulls. Don't miss checking shaft straightness like I over looked first time or two. I ain't hardly stopped fixing and wrenching on stuff - just to recover life's vitals - so ain't done much with cycles to matter. Oh yeah once sealing up all fixed up might consider thick grease or paint on outer cover parts above oil level condensation zone, with the next guy in mind.

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Me, fibbing??
Me, look in the gearbox??

You've got the wrong fella buster.
I pump tires up and even then make a hash of it. No fibbing!!

MkIII is ridden everyday but short around town/shops/post office/gym/pub type mileage, and in that order.
Then longer rides on weekends. It is a commuter come tourer.

Les, re in neutral but with no light on, you can only achieve this by sitting stationary for hours on end snicking the lever up and down ever so gently looking for an elusive neutral in these conditions. Takes hours of practise and patience but eventually you will find a neutral with no light on. I do it at the traffic lights, pisses cars behind off BIG time!!
Why not??

Phil

And as far as traffic lights go, I was taught by my father:
Yellow….proceed with caution.
Green…. go.
Red….go even faster. Except when practising finding lightless neutrals.

Works for me.

Considering all the linkages required, and having to turn the gear box upside down, the MkIII box works surprisingly well. Occasionally changing back to 3rd, I can find a false neutral, but hardly ever. Apart from that its operation is smooth and positive. Even more so perhaps than the standard AMC box. Lever movement may also be a tad shorter. The AMC box was never known for short lever movement. But it has been a while for me to compare the standard box without MkIII "modernisation".

I would still prefer right side 1up3down. For no other reason than that's the way it was. But either way or side, I couldn't really give a damn. So long as it works. The Triumph gearbox always had better short lever feel. But a Triumph never went like a Norton!

Alrighty then I take back my remark that thumb commsensors lower one's IQ, atleast in MK3's or MKIII's which is mostly meaningless confusing code to me. So now the pressure is on to to get to the bottom of what's snagging this AMC's snickerdoos. I've had enough fault modes to think popping out of gear in mild leaned coating turns is worse than shift fights.

Hobot - I did check primary tension when I adjusted my clutch. I didn't get an exact measurement but it appeared to be about 1/2" play. Manual calls for 3/8". I'll try to get that adjusted properly next time I go in, but it's certainly not overly tight. So here's my thinking on my issue - When I'm getting to false neutral on the 1st to 2nd shift, a quick downshift ( raising the shifter ) puts me in 2nd. Shouldn't my false be the cam sitting on the detent between 2nd & 3rd? If this is the case, then I'm thinking I should examine the detent plunger and spring. My question is this - part # 04-0036 Detent plunger housing, is this accessible from the bottom of the gearbox, forward of the drain plug? Parts diagrams are unclear as to where this housing is located.

ommief said:

Hobot - I did check primary tension when I adjusted my clutch. I didn't get an exact measurement but it appeared to be about 1/2" play. Manual calls for 3/8". I'll try to get that adjusted properly next time I go in, but it's certainly not overly tight. So here's my thinking on my issue - When I'm getting to false neutral on the 1st to 2nd shift, a quick downshift ( raising the shifter ) puts me in 2nd. Shouldn't my false be the cam sitting on the detent between 2nd & 3rd? If this is the case, then I'm thinking I should examine the detent plunger and spring. My question is this - part # 04-0036 Detent plunger housing, is this accessible from the bottom of the gearbox, forward of the drain plug? Parts diagrams are unclear as to where this housing is located.

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1/2" is just fine. Check it in a couple months.

ommief, i'm hanging around this old man's old motorcycle bunch as I don't know what further to add and need constant refreshing by others on what run into I didn't ever know or have forgotten between break down mysteries. Only two things matter on primary tension - IS NEVER EVER tension to what feels right-tight when cold and then just not so loose chain/belt flap into case so everything in between works fine. Best way is set loose and adjust for some flap when as hot as ever expect to get it, then set rear chain and remember what they feel like once cold again. I will rest easier once you report your sweet shifts again w/o thinking about em.

Thanks for all the advice & support on this issue, one and all! Saturday I decided to have at it once again. I drained the gearbox and then found the 18mm socket to be spot on for the detant housing plunger. Pulled that and the plunger and spring were good, though it did feel a bit gritty when depressed. I cleaned the black sludge out of the house and lightly polished both plunger and housing & reinstalled. I pulled the outer cover and re-inspected the ratchet mechanism. I gave a bit more bend to the top leg of the pawl spring and reassembled. I didn't think I'd really accomplished anything so I did some gardening for the afternoon. Four o'clock came around and I took her out for a spin, sweet shifting just like Hobot said! All gears engage with just a nice, light flick of my foot! I was feeling great on my ride until the bike coughed, coughed again and started spinning down, then stopped. WTF? Checked everything out and then checked the gas, empty!
What a rookie blunder. I had filled up the Triumph and remembered it as filling up the Norton. Speedo has no tripmeter which I always reset on the Bonneville and I had been running with both taps open. Lesson learned. I was able to borrow a gallon from a guy next door, rode back to the house after filling up and using right-side reserve tap only. Today I took another beautiful ride to verify sweet shifting - light, sure shifting with no misses. I was out in the car later so I grabbed a 12-pack of Leinenkugel for the nice guy with the gas. Thanks again for the advice & assistance, I hope everyone had a great Memorial Day weekend. Tom

Tom, Left me on edge of seat snicking ahead of your grinning to about falling off on heart sink sense of stoppage then laughing out loud of how it worked out in your sense of self worth and new souls to share the high with. During Peel era I got to point of unable to think of any more excuses not to see if 1st ever restore ran and it Did! so headed right off about mid night to show my brother Dale 18 miles away then headed home to sputter dead with heart in my socks, no driver license non current tag on main hwy, ugh, but ended up waking it 1/4 mile up hill to coast to 24 hr truck stop knowing I'll never do that again. I call our sense to ride into unknowns, scared confidence. Oh yeah poo on you getting away with a short cut Commando repair. Hope next show stopper goes as well.