Social kickstart

I finally got the head back on after the exhaust port repair and the bike is running beautifully, however my kickstart has started to wave at passing cars and even the occassional Harley rider. It seems to be totally non-judgemental, it will wave at anyone regardless of creed or culture.

Actually it has only given a few waves out so far, but I suppose this is fair warning for the layshaft bearing redo. Does this symptom indicate that an immediate fix is required , or will the bike run OK for a few hundred miles like this?

worntorn said:

Does this symptom indicate that an immediate fix is required , or will the bike run OK for a few hundred miles like this?

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DO NOT RIDE IT ANY FURTHER - for any reason, you run the risk of the gearbox and rear wheel locking up solid on you!
Pulling the clutch in and freewheeling to a stop will not be an option, and you are likely to destroy gears, shafts and maybe wreck the casing as well when the layshaft bearing finally breaks up.

Thanks LAB, I'll heed your advice. It is winter afterall, so it's a good time to have at the transmission.

Here's a link to a recent thread dealing with the layshaft bearing problem, which contains some information that you may find useful?: http://accessnorton.com/norton_commando925.html (3 pages)

worntorn, Every time the kick lever moved the bearing was spinning in the back of the gear box housing. The part of the bearing that is supposed to stand still. It was talking to ya.

I think you got lucky! Tear the gearbox down immediately! Don't ride any further. I was pretty lucky when my layshaft bearing disintegrated as it didn't do much damage to the gearbox and gears. However, I have heard lots of horror stories including high speed back wheel lockups, grenaded gearbox cases so please don't take a chance riding this bike! Recommended upgrade is to a roller layshaft bearing which should be better able to withstand the forces applied to the gearbox by the Commando engine.

I will take it apart and do the repair before riding again, however from reading the link L.A.B. posted, my MK111 should already have a roller bearing installed from the factory, correct?

worntorn said:

my MK111 should already have a roller bearing installed from the factory, correct?

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Various members have said on this forum that their Mk3s had the layshaft ball bearing fitted, and not the roller.

Hi all, as a matter of interest to do with replacing gearbox bearings, is it possible to do the replacement without removing the 'box from the frame?, I have the necessary bearings all set to go and don't want to take out the 'box if I don't have to.( 1974, 850 )
Thanks for your help.
James.

James,

It is possible to do this with the box in the frame, but it really does not save much time. You already will have the primary dismantled, so you are talking about removing the top and bottom gearbox bolt and the engine headsteady and one or both of the rear most engine to cradle bolts. The engine has to be pivoted to clear the opening in the cradle for the gearbox (unless your cradle has been modified to allow the gearbox removal without disturbing the engine mounts). Once out it is much easier to heat the end of the gearbox to remove the old bearing and insert the new one. It also allows you to thoroughly clean the inside and outside of the case.

If you choose to attempt this with the box in the frame, you may need a blind bearing puller to remove the old bearing. Heat the case to expand it around the bearing area. You may find the bearing simply falls out. If this is the case check the bearing recess closely for cracks, especially between the layshaft bearing recess and the mainshaft bearing recess. If it does not appear cracked, you may need to use Loctite stud and bearing mount to prevent the new bearing from spinning in the recess.

Thanks Ron, I will probably remove the 'box as you describe, take a good look at the casing and bearing housings.
James.

I second the opinion that the gearbox should be removed to work on it. Much easier to work on out of the bike. You can heat the case and inner cover in a gas barbecue to get the bearings out and new ones installed. Much more effective than a propane torch. There are two very detailed and helpful documents on the Old Britts web site regarding gearbox disassembly and reassembly that you might find helpful. Lots of good photos and step-by-step instructions. These really helped me through my gearbox rebuild. Good luck!

I found heating the case in the oven to be very effective. You want to control the temperature to prevent the aluminum from getting too hot.

Make sure you clean the oil from the case thoroughly before going in the oven. If you don't, the oven will stink like burning oil every time you heat up a frozen pizza! :lol:

Jason Curtiss said:

Make sure you clean the oil from the case thoroughly before going in the oven. If you don't, the oven will stink like burning oil every time you heat up a frozen pizza! :lol:

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"What's for dinner, honey?"

"EP90-infused frozen pizza, dear! Yum!"

:lol:

Debby