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Collection, Preservation and Display of Old Lawn Mowers

Atco clutch/flywheel puzzle

Hello, I am trying to remove the clutch mechanism from an Atco 24" (circa 1950's) H8 model. I have removed a similar clutch from a 20" F10 model which when disconnected from the bearings just simply pulled away from the flywheel. On the 24" H8 it is not quite so simple. It has been disconnected from the bearings but will not draw out and seems to be still fixed but can not see how. There is a rubber 'buffer' between the clutch and the flywheel and this seems free but internally there is still a connection somewhere with on obvious way to separate the clutch from the flywheel. I can see no fixing on the back (engine side) of flywheel or anywhere. HOW is this disassembled. I am trying to get at the clutch plates to fit on another mower. Any help with this will be much appreciated.

Forums

wristpin Tue, 26/08/2014

Don't fully follow  your explanation but I would probably take the engine off, just unbolt and pull array from the flexible ( cush ) drive . Then to remove the clutch carrier basket undo the countersunk screw set into the end of the clutch shaft. Here,  memory  fails me  but  something says that this may  have a left hand thread.

With the clutch carrier out of the way you can slide the plates off the square drive dog which may be secured to the shaft by either a roll pin or a split pin. If it's a roll pin make sure to support the shaft before driving it out.

The clutch set up is almost identical to the one shown in the parts manual for your other machine that I sent you last week.

Jon Tue, 26/08/2014

Sorry I have not explained that very well, doesn't help when I don't know what all the parts are called.

The clutch hand lever has been removed. The nut, bearings, chain  and housing have been removed from the side frame. Then I thought the clutch would pull away from the flywheel but its held somehow though it does wiggle around. Problem is I can see nothing else to undo that I can get to, even if I remove the engine. Do I need to take the flywheel off? if so how?

By the way photo taken before removing anything.

wristpin Wed, 27/08/2014

As per my earlier post, leave all the clutch in situ but remove the engine then the plates may be accessed with minimal dismantling of the clutch. Use the parts list that I sent you as a guide.

With the engine unbolted wiggle it from side to side and it will separate at tha flexible coupling and come away complete with the flywheel leaving the clutch accessible .

Jon Wed, 27/08/2014

Done. Unbolted engine as advised (thank you) and had more room to play with. Then with a bit of pulling the clutch separated from the flywheel. Reason for this being difficult was the bearing on the end was held fast from lack of lubrication. Anyway managed to take everything apart and borrow the clutch plates to fit onto the other mower and its still running hot and snatching. Now thinking the drive shaft may be bent.

wristpin Thu, 28/08/2014

That's good, by all means check out the shaft but what is the condition of the cutting cylinder and it's relationship with the bottom blade?  If the cylinder is not rotating freely, slacken off the adjusters a bit and test the clutch again.

Something else to check is that with the clutch engaged there is clearance between the thrust pads at the bottom of the lever and the withdrawal collar (part of the clutch pressure plate.. If not, it will get hot!

Correct adjustment is achieved when there is a visible clearance (say 50 thou) between the pad and the collar with the clutch fully engaged. It is equally important that with the clutch lever latched in the disengaged position the pressure plate is not withdrawn so far from the basket holding the plates that one can drop out of alignment.

I believe that on early machines the thrust pads were just metal protrusions on the two lever arms but on later machines they were replaceable metal and then fibre pads. The same basic design of clutch is still used, but now cable operated with ball race thrusts.  

Adjustment is achieved by altering the position of the lever pivot by means of the lock nuts each side of the chassis side plate.  .

Even with everything as it should be those Atco clutches were always quite harsh and needed delicate hand control for a smooth take off