ST4000 Belt -- Alternate Source

[Stu Jackson]

Shamelessly stolen from the catalinaowners website board:

Raymarine ST4000+ MK 1,2

I wanted to get spares for the belt on the autopilot and found this bit of information that I thought I would pass on. Raymarine wanted $70.oo for the belt. I did some searching and found out the belt is a:TAPEZOIDAL TOOTH Neoprene rubber timing belt, .200"pitch, Trade SZ 300XL, 30" outer circle 3/8" W. I found that McMASTER-CARR 6100 Fulton Industrial Blvd. Atlanta GA 30336-2852 carries that belt. I got two for a total of $15.55 Their part number is 6484 K239 if you care. Their telephone number is 404-346-7000. John USNret

All credit goes to:  LKYusnret of High Point, NC -- many thanks.

[karista]

My autopilot lever often disengages by itself, I jury-rigged a small chain cord to keep it from disengaging which works ok, however I would like to repait it correctly. The pin often mentioned, is ok and not broken, I therefore suspect maybe the belt has stretched. What is the procedure to replace this belt? Are the 2 round halfes just pressed together?

[Sailing Steve]

Having recently replaced the motor gear in the steering wheel drive of my older Autohelm 4000, I believe I can answer your question as I have had my belt in my hand.  I believe my older steering wheel drive unit has not changed significantly with the control head upgrades.  If I'd known about the alternate source, I would have replaced my belt as a preventative measure.

It is fairly straight forward to access the belt.  Remove the wheel from the pedestal, and optionally, the steering wheel drive from the wheel.  The two halves of the steering wheel drive will "snap" apart if you gently work a flathead screwdriver around the circumference prying the halves apart as you go.

This will expose the belt etc., and it is just a matter of doing a straight exchange with the new belt, then press the halves together with gentle hand pressure as you move around the circumference.  Watch that the belt is not getting pinched as you re-assemble the two halves.  The unit appears to be designed to be serviceable, and I've had mine apart a couple of times without any apparent risk of damaging it.

I ran the motor in both directions a couple of times to "balance out" the belt before I put the load of the wheel back on it - it may not make any difference in reality however...

Steve
'90 L'Abri
Hull# 1080

[karista]

Steve
Thanks for the information, I will order the belt from the supplier mentioned in this thread and replace my old one.

[Stu Jackson]

Another belt description and source

From: Chris Burti
Catalina C-320
Washington, NC

http://forums.catalina.sailboatowners.com/showthread.php?p=671427#post671427


FWIW, the belt is a simple timing belt. AT5 750 075 is a part number that fits the 4000+

It is a timing belt that has a 5MM pitch, 750MM length and 7.5MM width

Callahan Bearing is one supplier that reportedly will ship them at a reasonable cost, it has been suggest to give George a call at 215-368-4000.