Stuck sheave in Schaefer block

[captmikecoin]

My Liberty 49 is fitted with double row Schaefer foot blocks at the quarters to allow the foresail sheets to lead to their winches at the right angle. Unfortunately one of the sheaves is stuck fast despite attempting to turn it with a strap wrench. Neither will it pull off its axle which is welded to the frame.

Schaefer tell me that it is fitted with a Teflon/Nomex composite bearing which I have not been able to find out much about and their advice has been to use penetrating fluid. I am reluctant to do that without confirmation that it will not harm the bearing, perhaps by causing it to swell.

Does anyone have any suggestions? Freezing spray?

Mike

[Orion Jim]

Originally Posted by captmikecoin

My Liberty 49 is fitted with double row Schaefer foot blocks at the quarters to allow the foresail sheets to lead to their winches at the right angle. Unfortunately one of the sheaves is stuck fast despite attempting to turn it with a strap wrench. Neither will it pull off its axle which is welded to the frame.

Schaefer tell me that it is fitted with a Teflon/Nomex composite bearing which I have not been able to find out much about and their advice has been to use penetrating fluid. I am reluctant to do that without confirmation that it will not harm the bearing, perhaps by causing it to swell.

Does anyone have any suggestions? Freezing spray?

Mike

Schaefer can be trusted. I wouldn’t hesitate to heed their advice. Perhaps call them back and advise them which penetrating fluid you intend to use to ensure they have no issue with that specific product.
I have a single sheave unit with a bronze sheave and a stainless axle. Surprisingly they still stock replacement parts which I required to refurbish mine. Great customer service for 36 year old hardware.

[captmikecoin]

Just a quick note to say "I got the sheave off!" I used Crack-It from Arctic Hayes which is a freezer spray combined with some penetrating oil. I sprayed about half a tin onto the bearing and stub axle and after about 10 - 20 secs the sheave could be carefully levered off using two screwdrivers. Once the stub was cleaned up the sheave would run freely.

I hope this info is of use to someone.

Mike

[Jim Cate]

Good one! Glad to hear that you prevailed over reluctant hardware. It's amazing how hard it is to service many boat bits when they are neglected for a while. One suspects that the mfgs would like you to just buy new replacements.

Anyhow, well done!

Jim

[Boatguy30]

Don Greene can machine you any new parts you need. Greene marine

[searoom]

Good story.
Nice work freeing up and restoring the old deck block.
Tough quality block should go the distance.

Bob

[captmikecoin]

Thanks to all for your ideas and kind words.

Mike

[akero]

Hello,

Did you manage to find replacement sheaves? I have the exact same block and Schaefer marine are not able to assist unfortunately.

Thank you

[captmikecoin]

No, I didn't need them fortunately. The sheaves you may be able to get machined locally and probably expensively! The problem may well be the special PTFE composite bushes. You may have to settle for ball races if you can find any of the right size and then have the sheaves machined to fit the available bearings. I don't have any other solution except a complete new block. Sorry for your misfortune.

Cheers,

Mike

[dfelsent]

For what it’s worth igus has a fairly broad plastic bearing line. McMaster Carr has a lot of ptfe bearings as well.
I used some McMaster sleeve bearings years ago to replace some sheave bearings. I don’t recall the exact model though.