How to fix old worn slipping clutch/jammer

CapPugwash

CapPugwash

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Hello matey-forum-peeps.

I have a set of old clutches that are worn and allow the rope to slip. Do any of you have any tricks to make them grip again? I will replace them eventually but comfort down below always seems to take priority.

WornClutch.jpg
 
seumask said:
How about a bit of remaking the groves with a dremel. In my mind its all about re establishing those sharp / rough edges.
Click to expand...
I wouldn't do that, it will chafe the line; lightly roughening the areas polished by rope slippage with some abrasive wouldn't hurt, but the main grip is from the cam action so double check the rope is correctly sized, too big is as bad as too small. I've limped to the end of a season by leaving the slipping halliard on the winch and cleated off elsewhere, slightly awkward but it worked. You have had your money's worth, those jammers haven't been made since the 80s at least, possibly older.
 
How about a strip of thin stainless steel the width of the clutch. Place it in the bottom so it pokes out each end. Put a small screw into the deck to hold it to stop it slipping. This will effectively reduce the gap & make the clamping force tighter.
As a trial a piece of steel binding strap from a large parcel might work to test the theory. If you had a long piece you could trap the end with a pair of mole grips until you know it works.
 
I refreshed mine with a few careful strokes of an appropriately shaped file. The edges of the grooves/splines need to be fairly sharp to grip well and mine were ricely rounded off. I think that might be more controllable than a dremel. Compare the grooves and edges on the worn section with pristine ones that don't get reached by the rope and you'll see what needs to be done.
 
Have done mine ,whether because the line is too small or not,as Daydream Believer suggests but with thin aluminium strip.One end is turned down a touch and it is laid loose but stays in position.
 
We discussed the issue with a rigger when fitting a new dyneema main halyard - it is slightly slower on the drop into the stack pack for last metre or so but not an issue and clearly the halyard is far stiffer anyway due to material but it solved our problem re slip on a far newer jammer. Never have an issue hoisting but maybe that’s due to using an electric winch.
 
Have you tried washing the rope? Just put my main sheet through the mashing machine and it is like a different rope. No more twists in the blocks or slipping on the winch.
 
This may be obvious, but have you tried cleaning and lubricating the hinge?
As the cam grips and takes up the load, it will rotate slightly to increase the pressure on the rope. If the hinge, is stiff it won't be able to rotate easily and may not grip properly.
Assuming that the cam and leaver are aluminum and the pin is stainless steel, and the age of the clutch, it's likely that there are corrosion product causing excessive friction.
Try taking the rope out and give the clutch a good cleanout with some sort of solvent, then work an appropriate lubricant into the hinge pin and then clean up any split lubricant with an appropriate solvent.
Cheap and easy to do and might help solve the problem.
 
A close up look at the cams in the photo show that they are polished and worn in the fore aft plane.
Especially the red line and the right side vacant slot.
As mentioned 1 mm alu or stainless plate with a 4 mm (or so) lip at each end should stay in place and return the cam locking dimensions to what they were when the cams were new.
Remove the axle pin. Remove the cam and line.
Drop the plates into position and replace .
Worth a try and pretty simple job.
Let us know how it goes.

gary
 
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