more gearbox woes

[chris_blake]

i have a problem with the gearbox on my 86 mono it is a second hand replacement i fitted about 2 months ago. everything has been fine since untill yesterday when the changes started feeling slightly tight then today the gear lever would not return to the center position after changing down. if i dont get into first gear before stopping it wont come out of second without slipping the clutch and using a bit of brute force. it works ok going up the box except into top where it can take a couple of trys .it seems to change going into top ok when the bike is being revved higher than normal.any suggestions welcome as i do not think i can face another box swap. the sad thing is the old girl was running better than ever before. heres hoping its something simple. the oil is clean and correct level cheers chris

[Bob_Roller]

I had problems with my transmission after an overhaul, it was the shift shaft seal, it was put in crooked and was jamming the shift mechanism.

I'm not so sure that a seal issue would just show up all of a sudden.

Only other area might be the adjustment of the clutch cable, and again I don't think it would start all of a sudden.

I had a clutch cable fail on me, at the handlebar, where the swaged fitting is crimped onto the cable.

The cable started breaking there, and prevented the clutch from operating properly.

Just a couple of wild guess ideas, hopefully it's not the transmission itself.

[chris_blake]

i was wondering about the clutch as it does seem strange for this to come on so fast what about the actuating arm . the clutch does seem to be operating as it should thoughie not slipping or grabbing.i wont be able to check anything till the weekend but keep all the suggestions coming in as i have never had a problem that someone on this site has not been able to help with

[vestandpants]

agree with bob there, when I received my recon box it didn't have that seal however I had ordered a replacement as I was armed with that knowledge.

Also, it could be the gear change mechanism itself, check close to the peg for the grease nipple and add some till it comes out of the gap. Also, if the mechanism is similar to the pre-81, check the bar running from the top of the peg to the gear shaft from the box. Its held on with two clips. Check around it to make sure there are no foreign objects in there.

that's the best I can suggest. I hope it isn't the box matey, if it is the worst case scenario make sure you have the receipt handy

[vestandpants]

also check the left peg for movement. If the bolt is slightly loose it will alter the angle of the bar to the gear arm from the box. I reinstall mine last weekend and although the haynes screw-it-up-yourself manual didn't recommend a torque setting I did mine upto FT = T stands for 'tight' and the F does'nt stand for 'fairly'.

[Rob Valdez 79 R65]

You did lube the input splines when you installed the used transmission, right?

[chris_blake]

yes i did the splines the gear change and footpeg are all fine . thinking about it now i think it is not a clutch problem as it started with the gear lever not returning after changing down gear.i have a bad feeling that it is the box. but keep sending any other suggestions as i can check every thing else before i have to think about chaging the box again.of course my original box is sitting in the corner of the garage awaiting the rebuild.doh

[chris_blake]

just looked on motobins hints and tips page and it mentions a spring sitting against a camplate that can fracture. i was wondering if any one has had this problem.if so is it a gear box removal job. once again thanks for all the help keep it coming .cheers chris

[Justin B.]

The only spring I know of that is said to be prone to breakage is the "Pawl spring".  Yook further down for my transmission overhaul thread and there are pix...