Howard 350 cone clutch corrosion/friction material.

[rjy]

It’s getting there, slowly. This is the one that hasn’t run for about 25 years, but is in better condition than the newer (I think) one.

Took the clutch apart, to grease the bearings and splines. There’s enough friction material, BUT there’s powdery white corrosion on the light alloy inner cone, and the lining, which should be glued to that, has come away.

I don’t know where I can get a small quantity of brake lining/clutch lining glue (anyone?), so I was thinking of cleaning the clutch inner cone, and the friction material, applying a thin smear of “chemical metal”, and clamping it all up to let it set. I wouldn’t have thought the clutch gets burning hot.

Does that seem reasonable?

[rjy]

Well. Write-up, FWIW. In case it’s useful.

Took the clutch apart, using the opportunity to re-pack the bearings with grease.

I scraped off the outer surface of the friction material, taking care, it’s probably fragile. I also cleaned the cast iron outer cone, and the inside surface if the friction material, scraping gluey residue off, and the light alloy inner cone, dressing it lightly and evenly with a flat file.

It seemed a good idea to put the chemical metal on the alloy inner cone, so I did that, as it was easier than putting it on the friction material, wiping on a thin layer with a plastic spreader, then using a coarse hacksaw blade as a notched spreader to make it an even depth all ’round.

After that, I put the assembly into a press and applied light pressure until the chemical metal began to squeeze out.

Tomorrow I’ll get it out and fit it It will be interesting to see what happens if I can get the thing started. This is the machine with points, which is in rather better condition than the other one.

The thought occurred that it may have been better to use “Gun Gum”, use a couple of bits of flat bar with holes for a bolt through the middle, and a couple of spacer blocks to allow the cast iron and alloy to be pulled up, then when all’s ready, stick it in the oven on “low” for an hour or so before turning it up to 200C for another hour.

We shall see.

Quiet in here…

[disco2]

Hi it’s Will I have used JB weld to glue clutch shoe linings back on for my brushcutter also used it on a Hayter Osprey drive clutch both with good results. I tend to give the metal a rough up to give the glue something to grip to. Fingers crossed for you.
Best wishes William

[rjy]

“JB weld”!! That’s what I was looking for, had seen it mentioned, but brain ft made me think “Chemical Matal” which I had some of. Argh! Will keep you informed.

[rjy]

Well, I will test this tomorrow, but thought I’d better add this before I forget.

Problem: rebuilt clutch would not disengage.

I had re-glued the clutch friction material exactly, I thought, where it came off (distortions in the material back this up, and that the ends of the friction material met as they originally did). The clutch material overhung the end (larger diameter) of the inner cone by 1mm to 2mm max.

The clutch would not engage, due to the friction material fouling the inside (back) of the cast iron pully.

Fix: I filed off the back of the inner cone’s attached friction material. Clutch operation OK.

[rjy]

Ran the machine for about 1 1/2 hours today. The clutch survived the strain. Very rooty ground, old bramble “Turks heads”, long creeper roots, places I’d grubbed out smallish ash trees etc. It will need going over again a couple of times, but success so far.

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