Gearbox revisited

Back in July I asked about a problem with my gearbox - the kickstart lever pulls back when starting from a dead start.

The layshaft bearing had been changed after fisrt noticing this problem. The local and Brit bike mech. said everything looked ok.

Ron L asked if the previous (factory original) bearing had failed . No it didn't.

I've owned the bike since new and it hadn't been abused by burnouts or wheelies. Except that one accidental wheelie.

Ron suggested changing the kick start bush. He says it's a b*tch to change.

Now new info - the side to side/up down play of the kick start shaft is about .050"

In and out play is about .070"

These measurements are with the outside cover off.

Question, is this to much play? And does anyone have any tips on changing the kickstart bush?

Thanks

kickstart spindle bush

Hi Arch,
I can't comment on your play figueres, but, if your that far into it just go for it.
Its been a couple of years since a changed the bush in mine, but, as I remember I notched a little trench in it with a Dremel tool (ball mill). Then I dragged it out with a make-shift slide-hammer arrangement, IE. a long bolt with the head turned round and sharp on the edge. Catch the edge on the end of the bush and slide something against a nut on the other end.

justa thought,
geo46er

Arch,

The most successfull approach seems to be to find a tap large enough to cut threads in the bush, then screw in a proper sized bolt with a nut. Using a length of tubing (or a proper sized socket), hold the bolt and turn the nut against the tube, drawing the bush out into the tube. Good luck!

kick start bush

I agree with Ron. I bought a 3/4" Greenfield tap at the San Jose flee market for $1 (bearly if at all used) about 20 years ago for this purpose. Threading the bush then drawing it out as Ron said works good. In the last 25 years I think I've done this 3 times.

Arch,
They are correct, the bushing is very tight and there are several ways to remove it. A friend took a 'Sawsall' and cut it in half the same as suggested with the Dremel. I found a tool used to remove bearings from a blind hole (pilot bearings from the end of a crankshaft) and pulled mine out. It comes out hard all the way!

Another suggestion would be to take the shaft to a machine shop and have them remove and replace it. They can then ream it to the correct size while its in the shop. This would be a machine shop owned and operated by a machanist, not the shop in the back of the corner auto parts store. These people are almost always gearheads and like to do unusual jobs on wierd(Norton) stuff. The shop I use build bikes and race cars from scratch. They are also master welders and saved 'Pa's cracked transmission case.

I'm not sure you can actually measure the play in the shaft with the outer cover off. My mkiii outer cover also supports the outer end of the shaft. I was told that .070 was too much end play, fully assembled, and I reshimmed the layshft at the bearing end to get it to .025.

Did the mechanic who was inside of your box replace the bearing with a high quality roller bearing type?

A recipe for installing a new bushing into the kickstart shaft:
1) Clean the new bushing and put it in the freezer overnight.
2) Carefully clean all the grit, grease and grime off of the shaft, both inside and out with a good strong solvent.
3) Wash the shaft with a solution of hot soapy water until really clean and blow dry.
4) Assemble all the tools you will need before hand; an able assistant, big hammer, a drift just a little smaller then the diameter of the bushing (a socket with extension), a block of wood and two pot holders/oven mits.
5) heat oven to 250'f and "cook" shaft for twenty minutes.

--This is why the shaft has to be really clean, if you stink up HER house while cooking motorcycle parts in HER oven you and the bike may be banished to the garage forever!!!!!!!!!!

6) Place the block on the garage floor, remove shaft from oven, remove bushing from freezer.
7) holding hot shaft upright on wood block drop bushing into position and give it a really good smack with the hammer & drift and the job is done.

When my wife comes thru the kitchen and sees me wearing two oven mits, holding a pair of pliers and reading the workshop manual, she just shakes her head and walks on by. She never ask about the strange things in the freezer anymore either. Great girl, very understanding!

Sorry, but I seem to be having some trouble navigating thisa forum and posting with my signature.

The above recipe for cooking transmission parts was written by me.
Maybe this past will come out correctly.

Thanks for all the good info!

The bearing was purchased from British Marketing. There was nothing wrong (yet) with the original bearing.

Is the part no. of the bush 04-0146?

Thanks for the help!

Yup, my parts book says that's the one.

I just noticed I have the other bush, 04-0473. It came with a box-o-parts I bought a while back. Was curious so I looked up the number. Kickstart bush, inner cover. Brand new, still in the Andover Norton package. I suppose that one never wears out...

Debby

cooking

Oh, and here's an idea for keeping everyone happy the next time you need to cook some parts. Buy your wife a nice brand new oven. A good one, don't be cheap. Take the old oven out to the garage and wire it up. The next time you cook parts you can do so in the privacy and convenience of your shop. And the kitchen doesn't get all smelly. Everyone wins!

Debby

debby

I guess that you are lucky in that you dont have a wife to tell you DONT USE MY OVEN :lol:

bill

There's nothin' you guys (and gurls) don't know

Have you thought about half filling the old bush with grease and using the layshaft to hydraulic it out with a hide or plastic mallet? I recall it's a closed hole.......I think. Mine rotates, even with a new shaft needed when I converted the housings to Commando parts last year (my bike ran Dommie parts for years and I thought the stronger Commando spring might solve the problem. It didn't but it's not as bad). New roller bearing, straight layshaft etc doesn't seem to make a difference. What I have been told is that due to a very sloppy 1st laygear bush the situation can be worse. Mine is so loose that I will try this soon but that bush is thinwall and a real b**ch to replace without damage.....and it needs reaming.
Keith

Keith,

I tried the grease and an old layshaft ONCE! I only succeeded in making a big mess.

Are you saying the bush rotates in the shaft? I've never seen one that wasn't VERY tight in the kickstart shaft. If so your should be able to pull it out with a blind bearing puller.