Steering sheaves

[Brett]

Recently, I was inspecting our autopilot, quadrant, cable and sheaves.  I noticed that our upper port side sheave wasn't turning more that 15 degrees.  The cable is still solid, not showing any undue wear or broken strands.  We still have the bronze pins which I am replacing with the stainless pins.  But I don't know much about the sheaves....can the needle bearing in those be replaced by a machine shop or do you have to order all new sheaves ? Which run about $500 each......ouch....

[Soggy Paws]

Brett,

Unless there has been a change by Edson our sheaves are made with just a bushing that rides on the pin.  Original pins were bronze, new replacements are SS.  You should be able to buy just one sheave, but I think they are made of an aluminum alloy now. 

I recommend you call Edson and discuss your options with them.  After you change out the sheave, if necessary, be sure you check all your sheaves and place some oil at the pin/sheave contact point.

Dave

[Chip]

My sheaves had bronze bushings that were in good shape so I left them alone. There are needle bearings sized to match many common sizes of bushings so it is possible to swap the two. With a little care, the bushings can usually be replaced with nothing more than a hammer, drift pin and block of wood. Any shop with a press can make short work of it. Bearings need a little more delicate touch but are replaced the same way. If they are really stuck, heat the sheave. Industrial suppliers like McMaster-Carr should have the parts.

[Brett]

I spoke to Edson tech support shortly after I found the issue.....they were the ones who recommended the SS pin replacement ......they didn't mention the bearings though.....since I had time to do a little research I became curious about replacing the bushing/bearing without replacing the whole sheave.....

[Brett]

Just a quick a update....the pin was in good condition....some slight wear from the bushing and a few grooves worn in it.  The bushing seems to be the main issue....it doesn't seem to allow the sheave to turn at all, or very little.  Easy enough to remove but finding a new one may be a problem....Edson doesn't have any on its website.....I'm waiting on a call back from them.....all the other sheaves in the system are turning freely......later news...Edson finally called back they offer a one day turn around for bushing replacement !!!! To the UPS STORE !!!