Can an autohelm linear drive unit be user cleaned?

[S/V Elusive]

Originally Posted by Raven

Next comes the hard part - twisting myself back into its mounting and removing the unit. At 6'1" and 200lbs, I may have to solicit someone with a smaller body to perform the task. (One time I got myself so hopelessy "caught", hanging from my ankles and suspended head-first in the engine compartment, I though I was going to have to have a line tied around my ankles and be winched out off of the boom.)

I can SO identify with that. In fact, I have a couple of bilge pumps that need to be cleaned up (and one replaced). From my passageway deck level to the bottom of the bilge is 5 feet 3 in. I'm 6'6" 230 - I'm waiting until I get some help to do that one.

[DeepFrz]

Hey Raven, you get stuck down in the laz??

[Raven]

Yep. Headfirst down in the engine compartment. The PSC34 has a removeable panel in the cockpit, opening access to the engine from above. I went down in - to the point of doing a sort of handstand - feet pointing skyward. Took every effort I had to get out, with a bit of pulling from my 110 lb friend Johanna who was aboard at the time.

[DeepFrz]

I was just reading an article in Sail about servicing the Linear drive unit on an autohelm system. Apparently it was gunked up with refuse from the brushes. He cleaned that stuff out and it worked well afterwards. It was apparently easy to access the internals.

The article starts on pg. 75 of July Sail magazine. No details, just a little wordier than my summation above.

Raven, Raven, the trick is to send the 110 lb freind down there...

Deep

[Talbot]

Any chance of a copy?

[Doghouse]

Talbot,
It was a passing remark in the article, not the full article. The author stated that after sending it in once for replacement, the second time it started getting drive stop errors, he removed the drive and opened it up. Then proceeded with a soft bristle brush to remove all the carbon dust from the brushes. The drive has worked fine ever since.

I beleive that it was written that was as to not act as a recomendation to others to open up their drives unless they are willing to take responsibility for their actions.

[kimberlite]

Hi,
you probably just need to clean the brush dust out and replace the brushes. on a late model drive as you have the brushes are easily attainable from raymarine. did this on mine no problem.
if you will e-mail me back channel i will send you a parts diagram of a type 2 drive which is the same as yours but bigger.
fair winds,
eric

kimberlite at optonline.net

[kimberlite]

just use a can of compressed air then contact cleaner sprayed down the brush holes.
eric

[Raven]

I finally got around to inviting a dear friend to help me get at my linear drive unit so that I could fix it. At 5'2", Marion was able to get down in the engine compartment and make her way to the rudder quadrant. As expected, removal of the unit was not to be easy. The rusted clip that held the drive piston to the quadrant immediately snapped off and was impossible to extract with the unit in place. The attachment pin, bolted to the underside of the quadrant, had siezed up due to galvanic corrosion, as had the bolts holding the other end of the drive to its bracket. After a couple hours, though, we were able to free things up and get the drive out. From that point, it was easy and straight forward to simply remove the two bolts that hold the cover, free the sticking brushes, clean out the carbon, etc., and put things back together. All's well.

You just have to wonder why Raymarine is reluctant to share this easy proceedure. They are probably quite content having customers send in their units for the four or five hundred dollar flat rate service fee to have the factory do ten minutes worth of work. (Once the drive was out of the boat, everything else was quick and easy.)

[Milkman]

If possible can you forward me a copy of the parts diagram. I am in the process of rebuilding my linear drive and this would help get a few parts.