68 Bonnie trans issue

cwomike

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Slides into all 4 gears by hand but won’t go into first when running. I’ll start out in 2nd and sometimes get it to slip to first When riding. Sequencing of shift quadrant is corrector I wouldn’t find all 4 gears when riding.
installed are New Shift forks, new 1st and 3rd gear, new cam plate, everything else appears to be ok and serviceable. I’ve had it back apart too many times to count Any other suggestions are welcome. I’m not a rookie, built several others before this one but never seen this issue before.
thank you in advance
Mike
 

CarlS

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Mike, sorry to hear you are having problems with the tranny. I have not experienced this with mine. We have some experienced folks here and they can possibly help you. @grandpaul
 

triumph david

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That's a new one on me, may be something to do shims or spacing?
 

grandpaul

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Hmmmmmm....

Maybe the inner dogs in the 2nd gear cog are prohibiting 1st from engaging?

You really need to look close to find even 1 bent spline.
 

Twin Pots

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Slides into all 4 gears by hand but won’t go into first when running. I’ll start out in 2nd and sometimes get it to slip to first When riding. Sequencing of shift quadrant is corrector I wouldn’t find all 4 gears when riding.
installed are New Shift forks, new 1st and 3rd Tare the two never seen this issue before.
thank you in advance
Mike
Hi Mike, I had the same problem on my 67 T120R. I found that one of the quadrant springs had broken (two curved springs that act opposite to each other). Renewing the springs cured the first gear problem completely. If neither of your springs are broken it is likely this is still the area where the fault lies. After repairing mine I now sometimes have problem engaging fourth gear and have to pull on the gear lever twice. I suspect maybe I swapped round the spring loaded plungers or something. I will strip it and find out what's going on but I can live with it for a while. Check out the wear and springs on the plungers.
 

cwomike

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Hi Mike, I had the same problem on my 67 T120R. I found that one of the quadrant springs had broken (two curved springs that act opposite to each other). Renewing the springs cured the first gear problem completely. If neither of your springs are broken it is likely this is still the area where the fault lies. After repairing mine I now sometimes have problem engaging fourth gear and have to pull on the gear lever twice. I suspect maybe I swapped round the spring loaded plungers or something. I will strip it and find out what's going on but I can live with it for a while. Check out the wear and springs on the plungers.
Thank you Twin Pots. All springs are new but new can break too. I’ll give them a look
 

Twin Pots

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FJR 1300 Yamaha
Hi Mike, yes I thought you had suggested the springs were new. When I did mine first gear came back perfectly but I now have occasional difficulty engaging fourth cleanly. I had also considered maybe the new springs are not quite the same as the old ones in tension or compression. I still have one unbroken original. When I next strip the outer case off (next gear oil change) I will try to compare old with new. I also think it may be very difficult to gauge at what point wear on the plungers may affect things. Mine look fine but who knows? I am sure it's something to do with the quadrant that is causing your problem rather than something deeper in the gearbox as it sounds exactly the same as mine. When I pressed down for 1st gear it just felt like there was nothing there. Hopefully it is and you have no need to open up the box completely.
Always start with the easy things first is my motto. Good luck with it. Let us know what you find.
 

Lowboyjim

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hi mike i restore 1950s and 60s triumphs i have this problem on some of them i have 7 650s on the road presently and i like to get 500 mi on before i sell one , i have problems like you are experiancing often, its almost allways the spring adjustments , its a poor araingement to start with and adjusting the springs isnt as straight forward as it looks ,i tape the clutch lever to the handlebar and kick it over and watch the presure plates till i get it to stop wobling, another cause is several plates may be sticking together along with a woble. i like to use automatic transmission fluid good luck jim
 

Lowboyjim

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mike , here is a little more about the gear box problem , it helps to understand the animal , i love my triumphs but triumph has never been one to make things better than they have to be - for instance , they early speed twins of the fortys and fiftys had a 2 piece crank shaft with a fly wheel in the middle , that was fine then till they started making them more powerfull then they had to come up with a better crank which was suitable for the t120s that came off the assembly line, serious racers pumped the t120,and t140 even further, lots a flatracker's here in the US were geting over 70 HP , those racers had to rebuild the motors after a race or 2 they found cracks in the crank shafts, clutches have been a problem for anyone using more HP than stock , in the mid 60s the factory lightened the fly wheels for a year or 2 , and then went back to the heavier flywheels , because the clutches were slipping after moderate wear. we fixed that by tightening the springs , then it was draging like i think you are experiancing . i remember a couple a flatrackers i knew had a trick they did at the start of the race . the starter would get everybody up to the line , these guys would watch the rest of the racers and when everybody had their bikes in gear they would throw up their hands, and fidle around with something meanwhile the other guys clutches are getting hot , the trick worked half the racers clutches were slipping. and the tricksters would get the hole shot , i have had several 66s and had trouble with the clutches dragging or slipping , now i don't even put one together with a stock clutch , i buy a 7 plate conversion kit ,it uses 7 stock driven steel plates and 7 new type drive plates , the drive plates have a larger inside diameter than the stock plates so they don't touch or ride on the hub they only touch the basket. Im not sure why these work but they do- they are available thru JRC engineering - and guys like the bonniville shop etc, they are around $130 give or take not much more than a set of new stock drive plates that won't last long , i hope this helps you jim
 
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