Gearbx assembly

[a101960]

Much has been written, and posted about this topic. One of the things that has cropped up is the problem of gasket clearances having the potential to affect the operation of gear selection. What I would like to know is this: Do you do a "dry" assembly first to determine what is going to give satisfactory gear selection and then strip down and reassemble again using gasket cement? I ask this because if you put it altogether and discover that remedial work is required, then there is going to be a lot of mess from the gasket cement that needs to be cleaned up. I just want to be sure that I do everything in the correct sequence. I know that this must seem to be a daft question, but I just want to make sure that I do the job correctly.
John

[coater87]

 Hi John,

 You cannot go wrong running through as many dry assemblies as you need to.

 Use the gaskets (dry) and bolt everything up just like you were putting it together for the last time. Smear some clean oil or assembly lube in the bushes to protect mechanical parts.

 Then you can check all your clearances, make sure nothing is binding or clunks or rattles.

 Make sure you tighten bolts and screws up tight enough while doing dry runs that its just like the "real thing", that way you dont fool yourself on clearance.

 When your happy with everything and know the exact steps for putting it together, make sure everything is clean, lube everything up (you cannot over lube), and use your sealants.

 Make sure you lube the inside lip of any oil seals you have, you do not want those to run dry even for a second.

 while putting it together for real, keep checking your clearances when you can to make sure everything is going well. Do the same thing when its all done.

 I think the only really tricky part I found was timing the gears. After you get that figured out these really are not bad.

 Lee

[chaterlea25]

Hi John,
Its normally not an issue with swing arm gearboxes, unless you have replaced the layshaft bushes and need to check the endfloat,
As Lee said do a number of dry runs and make sure to get the quadrant marks set with the camplate in neutral
Sometimes the marks may not align perfectly so you may have to go one "notch" up or down

John

[a101960]

Thanks for advice chaps. I am glad to know that a dry assembly is a good thing to do. John I have not replaced any bushes, I have changed the quadrant ( which did not need changing but as I had bought a new one I changed it anyway) I have also fitted a new selector ( p/n 67-3341), that did show some signs of wear so that might have been the cause of the problems I was having, and also the two gear change selector forks. The problem was an intermittent inability to engage 2nd when changing up from 1st. If 2nd did not engage then changing back down 1st and trying again would get it to go in, but obviously it needed looking at. I just hope that the work I have done has cured it.

[Russ]

Hello guys,
Further to John's question, I am intending to rebuild my gearbox, 51 A10 Plunger, but it will not go into service for a couple of years. Yes that's right, a couple of years. This is a long retirment project when I get aroung to retiring. My question is can I rebuild it now and put it on the shelf. What would I have to do to make sure it is still mickey mouse in a couple of years.
Russ

[duTch]

 

What would I have to do to make sure it is still mickey mouse in a couple of years.
Russ

 Maybe find some Minnie Mouses for the Mickey Mouses to keep them away from exercising on your unused box 

[Greybeard]

...My question is can I rebuild [the gearbox] now and put it on the shelf. What would I have to do to make sure it is still mickey mouse in a couple of years.

This may have been better asked in  a new topic.

[edboy]

yes you must set up the gearbox on a bench. set the cam plate plunger for nice smooth gearchange - not too stiff which 2 threads showing can. if it jumps out of gear on the road its easy to get to and  wind in a turn. i always fit gaskets on plunger boxes and use wellseal on inner gasket. temporaly fit outer cover and check selection , kickstart/ cotter pin, sleeve bushes. bsc screws for outer cover inspection plate. etc.

[bikerboy]

I have to be honest if I am stripping and rebuilding a gearbox I flatten the surfaces and just use a touch of grease on the gaskets no gasket cement at all.

I think its about the only place on an A10 I have never had a leak from