Autopilot makes grinding noise

[gregorybross]

I have an Autohelm ST4000 Plus wheel autopilot. I has started to make a grinding noise when engaged and operating. Does anyone know if there are bearings inside of the black discs that can be replaced? The manual says that the unit is permanently lubricated.
Greg

 

[rpell1@msn.com]

Chances are.............

Hi,
Chances are your drive belt is worn and your "jumping" teeth.....or the two sides of your drive wheel are separating far enough to allow the drive belt to slip.

Another "winter" job for you.

Happy New Year.

I have an Autohelm ST4000 Plus wheel autopilot. I has started to make a grinding noise when engaged and operating. Does anyone know if there are bearings inside of the black discs that can be replaced? The manual says that the unit is permanently lubricated.
Greg

 

[Calif. Ted]

Last time I heard that noise the belt was shredded, got a replacement from Polybelt.
http://www.ebay.com/itm/Replacement-BELT-Raymarine-D169-Autohelm-ST4000-AutoPilot-Raytheon-Wheel-Pilot-/170975143285?pt=Boat_Parts_Accessories_Gear&hash=item27cee9a575

 

[gregorybross]

Thanks guys! Just ordered a new belt.

 

[smokey73]

Never hurts to have a belt but it could be something I ran into on a delivery from New York to Annapolis.

Inside the ST4000 black wheel are several rollers. Each wheel rotates independently around a small brass sleeve that is held in place by a plastic pin. Several of the pins had broken and the wheels were just dangling in there and "growling" as the ST4000 was engaged and working. I had to do an emergency repair after we hit some heavy seas leaving New York Harbor and pulled into Atlantic City. I drilled out the pin and used stainless steel screws in place of the plastic pins, screwed into the portion of the black wheel that is most forward (the fixed portion). I then dabbed a small amount of super glue to where the stainless screw now protruded ever so slightly through the black wheel. This has worked remarkably well and the wheel works great now so I plan on leaving it as is. I wish I had taken pictures but I'd almost bet that may be your problem.

If you find that and want to pm me with a phone number we can discuss an maybe I can explain it a little better.

 

[Anonymous 121765]

G-man,

I liked what Smokey said. I had similar problems with my AP. I also replaced some rollers using screws. Another problem was my locking cam. I needed to change that also, because it failed.

I can tell you that the belts are a petroleum based material. The bad news is that sun, UV weather differences & salt effect them over time. This is what dries them & they shrink & become hardened. I've had my AP since 1992 with only the one fix mentioned above. It's 22 years old but still going strong. I believe using a binnacle cover had a lot to do with this. I had a nylon(?) inside covering I believe cuts down on UV and moisture.

Problem with plastic rollers & locking cam is that as the belt shrinks, more pressure is applied causing them to wear. The first sign it's time to change the belt is when releasing the lock, I can hear the belt teeth "slipping sound," like it' not fully released.
Another thing to look for is if engaged, you find the lock lever lifting up on it's own.

I waited too long the first time. Had I changed out the belt early on, I probably would not have worn out the parts. I always order two belts. I keep the spare stashed in a low compartment in a black trash bag. UV (the monster) goes right thru fiberglass. I had a spare belt onboard on one of my shelves, for two years. When I went to use it, it was as bad as the belt I was changing out.

CR

 

[smokey73]

I also had the cam problem. What I found is that a small stainless steel pin that goes through the lever and then the shaft of the cam had broken. That caused the lever to be only held onto the cam by friction and that was not enough to hold the cam in place. As Captron noted, the lever would then disengage slowly and I'd see us drifting off course. I drove out the remaining pin inside the shaft of the cam with a finishing nail. Then I experimented with stainless steel finishing nails until I found one that would fit snugly and cut it to the correct length, inserted it through the lever and shaft and dabbed a bit of super glue to make sure it stayed in place. It was snug so the super glue was just for security. It has worked perfectly so if some of you have an ST4000 that comes disengaged you might want to check the pin. Again, I wish I had taken pictures but the fix is fairly straightforward once you realize the problem. By the way "I'm not a shipwright, but I stayed in a Holiday Inn last night!" (Actually I am a nuclear engineer and submariner - you need to jury rig things now and then - but not the nuclear reactor of course)