Hi,
I am currently cruising down the east coast and have run into a problem
with the autohelm 4000 wheel autopilot. When in the disengaged, free
wheeling position (such as it would be in on standby when hand
steering), it still engages and will not turn freely--- it kind of
ratchets over the drive gear teeth.
Does anyone have any idea what might be causing this???

TIA

Otter

It sounds like the clutch is not disengaging but I'm not familiar with
the internals of the unit. You might try asking the question on
"rec.boats.electronics". There are several experienced marine techs
who hang out there.

"otter" wrote in message
oups.com...
Hi,
I am currently cruising down the east coast and have run into a problem
with the autohelm 4000 wheel autopilot. When in the disengaged, free
wheeling position (such as it would be in on standby when hand
steering), it still engages and will not turn freely--- it kind of
ratchets over the drive gear teeth.
Does anyone have any idea what might be causing this???

TIA

Your fault is strange, the problem is usually the belt slipping or the lever
disengaging. Anyway, the 4000 is easy to strip and reassemble. The two
halves split apart with the aid of a flat blade screwdriver or even a large
coin. The belt runs around a lip in one half of the casing and round the
tensioner and drive motor in the other half. As you take the two sections
apart, the belt (if not under tension) should slide off the lip and all the
components are all on view.

Graham.

"otter" wrote in message
oups.com...
Hi,
I am currently cruising down the east coast and have run into a problem
with the autohelm 4000 wheel autopilot. When in the disengaged, free
wheeling position (such as it would be in on standby when hand
steering), it still engages and will not turn freely--- it kind of
ratchets over the drive gear teeth.
Does anyone have any idea what might be causing this???

TIA

Your fault is strange, the problem is usually the belt slipping or the lever
disengaging. Anyway, the 4000 is easy to strip and reassemble. The two
halves split apart with the aid of a flat blade screwdriver or even a large
coin. The belt runs around a lip in one half of the casing and round the
tensioner and drive motor in the other half. As you take the two sections
apart, the belt (if not under tension) should slide off the lip and all the
components are all on view.

Graham.

Thanks for the help! I have also posted on rec.boats.electronics

Does anyone know if the principle of operation is that the belt
disengages from the drive gear, or does it slip on the driven drum??!!
I am thinking that maybe the belt is old and doesnt have enough
stiffness to pull back from the teeth?

I have had the unit apart, the only thing that seemed a bit amiss is
that the idler wheel that is moved by the lever seems a bit sloppy--
maybe it is binding?

It's a weird one. I was hoping for a "Oh yeah, mine did that and it was
__________!"

Thanks again!

Otter
Catalac 8m
Currently in Cocoa, FL headed south

Oh yeah, mine did that and it was a sheered pin in the idler-wheel
where it connects to the shaft that goes to the lever arm.

I drilled it out and put a bigger pin in, though it's hard stainless
and the parts are small and hard to work with.

The belts go bad, too. You can get a new one from West Marine for $55,
or fir $8 from:
9.5AT5-750 Urethane Steel
Belt Corporation of America, 1-800-235-0947
http://timing-belt.com/urethane_steel_at5.html#top

Another common problem: The little wheels around the rim of the
mechanism break off. I bolted them in place using locknuts so they can
still rotate.

Here's the service manual: http://www.ganssle.com/jack/st4000.pdf

Jack
Sailing stories: www.ganssle.com/jack


otter wrote:
Thanks for the help! I have also posted on rec.boats.electronics

Does anyone know if the principle of operation is that the belt
disengages from the drive gear, or does it slip on the driven drum??!!
I am thinking that maybe the belt is old and doesnt have enough
stiffness to pull back from the teeth?

I have had the unit apart, the only thing that seemed a bit amiss is
that the idler wheel that is moved by the lever seems a bit sloppy--
maybe it is binding?

It's a weird one. I was hoping for a "Oh yeah, mine did that and it was
__________!"

Thanks again!

Otter
Catalac 8m
Currently in Cocoa, FL headed south

I constantly had that problem. The best solution is to spend the young
fortune on their Wheeldrive II. A much better unit with the insides
all metal and with bearings.

However, there is something you can do about it. Well, a couple
things.

First, pop it apart and clean it. This may do it.

Second, there is a tension adjustment. I'm trying to remember exactly
where. I think it's close to the motor. Look on the motor side for a
plastic cap and pry it off. There's an Allen wrench adjuster with a
locking nut. The locking nut has a couple holes for a tool. I used a
pair of needle nose pliers that have about a quarter inch "bent" at a
right angle. Turn the adjuster a tiny bit and try. It's a very
sensitive adjustment. Too far one way and you get your problem, too
far the other and it won't stay engaged.

Rick

On 1 Jan 2006 14:53:06 -0800, "otter" wrote:

Hi,
I am currently cruising down the east coast and have run into a problem
with the autohelm 4000 wheel autopilot. When in the disengaged, free
wheeling position (such as it would be in on standby when hand
steering), it still engages and will not turn freely--- it kind of
ratchets over the drive gear teeth.
Does anyone have any idea what might be causing this???

TIA

Otter

This is a little "off topic" for this particular thread... but I
couldn't help but notice that Mr. Ganssle recently posted/
participated here.

In his posting he noted his personal web site:

www.ganssle.com/jack

About a couple of weeks ago... I was surfing the internet and
stumbled across the aforementioned web site. Once I opened
it up... I was totally engrossed in it's contents. For those of
us that love the sea and sailing... will find his accounts totally
awesome! He talks the talk... but has done the walk... so to
speak.

Enjoy... one heck of a fine "read" and thank you Jack for your
time and contribution to the sailing community.

Bill

On 2 Jan 2006 10:09:17 -0800, wrote:

Enjoy... one heck of a fine "read" and thank you Jack for your
time and contribution to the sailing community.

============================================

It is one heck of a read. Anyone contemplating a transatlantic
adventure on a small boat should definitely read "Go West".

Bill, thank you for pointing out the web site, and thank you Jack for
writing down all the details of your gut wrenching experience. I feel
your pain.

After much experimentation I believe the following:

1. That the principle of operation is that the belt loosens up and
doesn't grip the turned drum.(I might be wrong about this)
2. After loosening the belt tension all the way, my unit works fine.
3. I broke off two rollers and found a way to split the locking nut in
half (that secures the eccentric belt adjuster).
4. This is a higher level of destruction, even for me, than would be
typical for a fix of this magnitude. It is an older unit.
5. I guess I don't care about the adjuster so much since I want it
loose anyway.
6. I should buy a Mk II unit and keep this one for a spare.
7. http://www.ganssle.com/jack/ is an excellent website. Wonderful
writing, sublime experiences, very helpful manuals et al. Thanks Jack!

So for now that concludes my wee experiment with the Autohelm 4000.
Thanks again for the help.

Otter