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Discussion Starter #1
I know that this has been done to death, but here goes. I have just reassembled the 5 speed box on my 140D, after having replaced the layshaft 5th which had a broken tooth .
I have read all the threads on timing or indexing the quadrant to the cam plate, by setting the camplate to either 1st or 5th gear and holding the quadrant in the appropriate position while fixing the inner cover. I attempted to do this and was unsuccessful in locating all the gears. I was not too worried, as I had yet to refit the back wheel and chain (waiting to replace a buggered wheel bearing) and realised the process will go a lot more smoothly with the wheel in place to rotate the gears.
But it occurred to me that I have a neutral switch which is activated by the quadrant when a dimple on the quadrant presses against the switch. Wouldn't I be better off positioning the quadrant so that the neutral switch is in the on position, putting the cam plate to neutral and finishing the assembly?
Subsidiary question: when I reassembled the gears, placed and tightened the fixing screws on the inner cover, the gearbox seized - sprocket would not turn. Investigating further, and after backing off the screws, it was seizing on the last turn of the phillips head screw. I have the old worn gasket still in place until I finally sort things out. Are tolerances so fine and end play so limited that a worn thin gasket can gum things up? I am thinking of making a gasket from some thickish cardboard to increase end paly. Are there any traps in this?

Advice welcomed - thanks


Steve
 

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Indexing in 1st gear is easiest because the quadrant naturally sits close to that position.
Ensure the plunger is in the correct camplate valley.
You just need to pull the quadrant down a little.
The top of the first tooth from the bottom ought to align with the centre-line through the gear lever hole.
(for neutral, it`ll be the 2nd tooth)
You need to rotate the rear wheel to check gear selection.
If 1st or 5th is unobtainable, yer indexing is wrong.
This may help, although it`s naff :D
http://www.triumphrat.net/classic-vintage-and-veteran/141250-indexing-5-speed-gearbox-in-1st-gear.html

It needs to be in neutral after assembly to turn the sprocket.
 

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Hi Steve,
If your gearbox is binding when the inner cover is tightened you may find that one of the thrust washers are not sitting as they should. There is one on the inner cover and another on the inside of the box next to the layshaft. Both are located with a small protruding stud that should locate in the hole of the washer.

I hope this helps

Webby
 

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Discussion Starter #4
Thanks Caulky. The workshop manual says " line up the top edge of the second tooth of the quadrant with the centreline passing thru the footchange spindle housing", although the diagram ( a bit hard to see, admittedly) seems to support your advice that the top of the first tooth should be the one to line up. I will go with what you suggest.
Webby, with my luck, if a thrust washer is not sitting correctly, I will wager my left one on it being the primary side washer!!
I'm getting pretty good at pulling this box apart!
 

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Hi Steve,


Thank you for the timely post. I will be re-assembling my gearbox in a few days when my parts arrive.

Just curious, did you resolve the stack-up issue? Was it one of the thrust washers?
 

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Discussion Starter #6
Hi Bikeman,

no, haven't got back to it yet, maybe tomorrow. I was pretty careful with the thrust washers, so I hope that isn't the problem. It only binds up with the last turn of the phillips head screw, and that is with a very worn and thin old gasket. Not sure how much end play should be present. I'm hoping that a new gasket with a bit of silicon will make the difference. I also read a thread that, even with a partial reassemble to test gear selection etc that the nut, washer kickstart ratchet & pinion etc should be fitted. I don't see how this would be critical regarding end play, but who knows.
Anyway, I will take the opportunity to tack an additional question to this thread:
when I took the selector rod out, I failed to notice that one end was slightly flattened (ie a slight cut out about 1/2"" long. I don't know if this is unique to the later model 5 speeds, but does any one know of this end goes in the primary side or the timing side?
 

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Hi Steve,
The flattened end of the selector rod goes into the roller bearing in the primary side.
As the bearing is closed, the idea of the flat on the rod is to prevent a hydraulic lock. It's the same on the later 4 speed boxes.

I hope this helps

Webby
 

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Fitting the kickstart pinion, ratchet, nut, etc, is neccessary for mainshaft alignment and gear mesh to the layshaft.
*You will need to temporarily fit the outer case and gear lever with 2 or 3 of the screws.

Try fitting the selector-fork shaft the wrong way round, [round end] with a drop of oil in the locating hole...it wont go!
Pressure will build up and the shaft wont locate fully.
 

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Discussion Starter #9
Thanks Caulky & Webby - timely advice, I have just finished putting it all together again. Took several goes. after one attempt, the shafts were binding and I found that one thrust washer was definitely not sitting correctly. I took a fair bit of time confirming that the cam plate would turn & locate all gears before putting on the inner cover. I did use the neutal switch to confirm the quadrant was in neutral position, and put the cam plate to neutral to index. I was a bit concerned about the systems' general reluctance to definitely locate all gears, but am being optimistic and put this down to little lubrication and incomplete assembly and alignment.
I've got the clutch to rebuild on the other side and will report back when that is done and I can crank it up and get the shafts turning at a decent rate of knots to assess how the box is performing.
 

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Discussion Starter #11
Hi Andrew
I see you are going thru the same process how did it go?
I got mine back together but too wet to take it out on the road - hopefully tomorrow. I did a bit of a dry test in the garage and it selects all gears OK and none of the noise that caused me to tear it down in the first place.
If any lessons learned I would stress:
1)document by photo, labels, or whatever, every gearbox item you remove, one at a time. I managed to put a mainshaft gear on backwards but eventually nutted it out.
2)on reassemly, make it a complete - albeit dry - assembly of all components, not just the ones that seem necessary
3) allow for the lack of lubrication if you have difficulty selecting gears
4) if you are lucky enough to have a neutral switch (140E & D's), indexing is made fool proof by putting cam plate & quadrant in neutral
5) ask plenty of questions - someone here will have the answers

Steve
 

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Discussion Starter #12
OK - just to close off this thread:
Fine morning here and I took the bike out for an hour. This was basically my first run with it, apart from a couple of short aborted testing rides. I have rewired it, rebuilt the clutch, and now the gearbox, and fixed up a heap of little stuff such as front & rear brakes, gearbox and wheel sprocket, etc, etc.
Verdict - absolutely beautiful. Selects all five gears and changes so easily and positively. Not like my old Enfield with 8 gears (1st, 2nd, 3rd, 4th & 4 false neutrals).
Very happy man at the moment, and I will now start looking at some of the cosmetic defects in the bike.
Thanks to all.


Steve
 
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