Another clutch anomaly

When you pull the clutch lever in the following happens......

1) The pressure plate lifts.

2) As the pressure plate lifts the 3 springs are stretched and pull on the spider body, which is bolted to the gearbox mainshaft.

3) Inside the gearbox, the mainshaft has a splined shoulder on which sits the 3rd gear. This shoulder butts up against the sleeve output gear that has the gearbox sprocket on the outside end and the big cog that gives first, second or third gears on its inside end. When the clutch is pulled in the gearbox mainshaft gets pulled towards the shoulder of the sleeve output gear.

4) If the RLS 5 2LS bearing........the small one on the kick start end of the mainshaft is worn or loose.....the actions above will cause the mainshaft to rub on the sleeve output gear causing all kinds of badness to happen.

5) To check if your RLS 5 2LS is worn heave the clutch body in and out. If there is movement or clicking the bearing is worn or the nut on the mainshaft has come loose. Better to take the clutch right off and pull directly on the end of the shaft.

See attachment for diagram of inner chunks.

Attachments
gearbox-drawing-section-jp-jpg

Not a lot.

The main shaft is free to float between the bronze thrust washer and right hand bearing. When you pull the clutch in it will force the main shaft against the thrust washer and make the high gear harder to turn. You felt this as resistance at the rear wheel.

Colin

Like Phillip, I thought the main shaft was attached to the end bearing and inner cover by a nut, I canât see how it floats?

Dan

I recall that George has a lay down gearbox. The main shaft is not positively restrained by a nut on the right hand bearing. The end float is controlled by a bronze thrust washer between the shaft and high gear one end and a shim the other. Effectively the shaft floats between these. Hence you see posts on here about checking the condition of the thrust washer in cases of clutch drag etc.

When you pull the clutch in you are pushing the clutch to the left. As it is attached to the main shaft this is also pushed to the left. The bronze thrust washer mentioned takes this load. Even with oil there will be friction between it and the high gear on which it bears. In neutral when you turn the wheel with the engine stopped and you disengage the clutch you feel this resistance.

Later AMC, Triumph, BSA etc boxes have the shaft positively located by a nut on the right end as explained by Philip so this is much less noticeable.

I've noticed something similar with my ES2 (laydown box). In neutral, with the engine running on the centre stand (rear wheel off the deck), the back wheel doesn't spin unless the clutch is pulled in. This confused me a little till I read the above after which it makes perfect sense.

I remember my Commando, where the back wheel would always spin in neutral with the clutch engaged but of course that's the later AMC type box with the positicely located mainshaft.