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Collection, Preservation and Display of Old Lawn Mowers

Drive clutch plate and cable

Hello,

The cable to the drive clutch control broke a few years ago and now I have replaced it with a new cable and adjuster. It does not presently work. Manually the lever (seen here connected to the lower cable) yields a slight outwards movement of the clutch by less than 1cm on the side of the machine and it does not return when you remove the force. Can this be adjusted/lubricated so that it returns to it’s starting position which I presume is the centre? The cable is in situ without any tension.

I had a good look around on the forum and have seen similar mowers and problems and learnt this could be a large job if seized. Not sure if need to strip down the traction clutch and investigate further or not? There is a You Tube video by ‘Fred Fish’ that mentions a ball pressing on an adjuster when you take the cover off at the side and remove the cover on the drive clutch friction plate. It also shows the ball bearings inside which I noticed some members have cautiously advised they do not fall out. I have not began to do this yet.

 This mower has been operated by using just the clutch from the engine which engages the cutters but it is difficult to keep stop and starting using this alone. I would love to be able to slow it down and speed back up again using the handle. Any advice/help would be appreciated including terminology so I know what to search the forums for. Alternatively point me in the direction on the forum of a similar episode please.

Regards,

Forums

wristpin Wed, 24/03/2021

Yes, take care if dismantling the traction clutch as there are 50+ 1/8" ball bearings that can drop out. Best to stand the mower on a tay or something to catch them if they do. Running through the centre spindle are two push rods with another ball between them and these can seize up and prevent correct operation of the clutch. 

I'll post a couple of images later

 

Stellacerveza Wed, 24/03/2021

Thanks for the quick reply. If you get a chance to put up a picture of that centre spindle and push rods with bearing in, it would be a great help. A pointer is just what's needed and I'll soon have it working again. 

Stellacerveza Wed, 24/03/2021

Making a start, looking on the reverse, inside the clutch plate it looks about 1mm thick and has a slight crack. Is this the problem? Managed to drop two or three of those tiny bearings while I was distracted  removing the chain link. Luckily most of them were caught by the newspaper.

Was grateful for the warning!

Also the cover plate that holds this on was tightened to it's maximum amount. And the part shown below with the three prongs has about 5mm play ( in/out) in the  which I presume is normal to help the clutch engage.

There is a central spindle in the middle connected to the cable lever.

 

Stellacerveza Wed, 24/03/2021

Thank you

Stellacerveza Thu, 25/03/2021

With a bit of spray on it last night I came along and broke it today. The clutch plates were stuck, with a bit of attention they will be clean again. Lots of built up stuff on the chain, it's never been cleaned. I should have used heat on the nut like I usually do but who knows? It may have been brittle. Not my best day, so for now it remains a puzzle how to put back together. 

Stellacerveza Sat, 27/03/2021

I felt a bit gutted when the nut sheared off the end of the spindle so I tool some advice from another forum (mig-welding) and bored it out and tapped it. The new threaded rod need a hole drilled through to allow the push rod.

Now away from the engineering and more about the mower. The original problem was clutch plates were stuck together. I did not even appreciate the simplicity of this system until I began work on it. I cleaned the clutch plates, all the little bearings and the two adjacent chains with engine degrease and applied new grease and started reassembly. 

It still needs loctite on the threads but it was re-assembled on a wing and a prayer. I could not believe I got it repaired by finding the bits I had already and only getting help of forums. The schematic diagram was a great help. 

If it stays good and works well I will continue to restore it because I was faced with losing this heirloom. 

Stellacerveza Sat, 27/03/2021

I felt a bit gutted when the nut sheared off the end of the spindle so I took some advice from another forum (mig-welding) and bored it out and tapped it. The new threaded rod need a hole drilled through to allow the push rod.

Now away from the engineering and more about the mower. The original problem was clutch plates were stuck together. I did not even appreciate the simplicity of this system until I began work on it. I cleaned the clutch plates with Turfanega, all the little bearings and the two adjacent chains with engine degrease and applied new grease on and started reassembly. 

It still needs loctite on the threads but it was re-assembled on a wing and a prayer. I could not believe I got it repaired by finding the bits I had already and only getting help of forums. The schematic diagram was a great help. 

If it stays good and works well I will continue to restore it because I was faced with losing this heirloom. 

Stellacerveza Sat, 27/03/2021

I felt a bit gutted when the nut sheared off the end of the spindle so I took some advice from another forum (mig-welding) and bored it out and tapped it. The new threaded rod need a hole drilled through to allow the push rod.

Now away from the engineering and more about the mower. The original problem was clutch plates were stuck together. I did not even appreciate the simplicity of this system until I began work on it. I cleaned the clutch plates with Turfanega, all the little bearings and the two adjacent chains with engine degrease and applied new grease on and started reassembly. 

It still needs loctite on the threads but it was re-assembled on a wing and a prayer. I could not believe I got it repaired by finding the bits I had already and only getting help of forums. The schematic diagram was a great help. 

If it stays good and works well I will continue to restore it because I was faced with losing this heirloom.

mrtooley Fri, 02/04/2021

This is my first (hopefully useful) reply and first video uploaded, just because I've not seen it anywhere else! I took my atco clutch apart, removed rust from washers and replaced a broken friction disc. From the discussion so far it looks like your problem in elsewhere, but I can say that my clutch cable doesn't move the 'actuator' that far, but the actual clutch was originally stuck due to rust.

https://youtube.com/playlist?list=PLwrjXpyRN8dqRJ7CHmEb3Qo-0H7_H51s2