1980 F-32 prop shaft

[kiltsup]

Think my prop shaft might be leaking as I am taking on water when in motion. No water appears to coming in when docked, only in motion. Any other ideas as to what might cause taking on water when in motion? Any bottom side seals I might need to replace or look at, tighten?

[g36]

it should drip at the packing while the shaft is turning. it doesnt need to be a flood by any means but this keeps the shaft and packing cool and lubricated by water. its okay if not leaking while sitting at the dock. you also have packing at the rudder posts which really doesnt need to drip since there is not alot of movement like the propeller shaft spinning. these might be harder to check since at least on my f32 its a little hidden. have you looked at these areas while someone is driving the boat? how much water are you taking on? take a good look at water hoses on the engine while its running maybe you have a bad hose.

[aaronbocknek]

i had a similar problem since i bought the boat in 2008 then in the spring of 2009, my mechanic and i took out the old packing material and repacked the stuffing boxes with 3 rings of goretex packing. it's super slick and they do not leak one bit, even underway. sort of a poor mans version to dripless stern tubes as you can get. future buyers of my boat take note on that upgrade.... and it's in my maintenance log book too.

aaron in baltimore

[k9th]

When you say "taking on water" how much are you talking about?

As stated above, you will get some dripping by design when the shafts are turning, and that drip amount can be adjusted to appropriate levels.

If the amount you are taking on represents more than that, you may want to look elsewhere to discover its source. There are a number of things that could be leaking while you are under way that may not leak when stationary at the dock.

[aaronbocknek]

dad's tri cabin experienced this prior to his selling the boat in 2008. it was traced to a bow area through hull fitting that had the caulk blasted out of when it was pressure washed. every time that displacement bow wave hit the through hull, water gushed in, down the inner side of the hull and into the lower areas of the bilge. i suggest that you run her at 1500 rpms, have a friend of yours operate the helm and you lay down on the forward deck and look down at where the bow wave hits any above the waterline through hull fittings. the one on our tri cabin was just under the forward port side berth.
other areas are leaking exhaust hoses in the genset and engines, leaking water pumps genset and engines, even water coming in side air vents. other leaks can take place in fresh water lines and the fresh water pump. you might want to check your fresh water tank too.... might not leak when docked and level, but in a bow up configuration, water might be leaking out of the hose from the tank to the water pump.
hope this helps.

aaron in baltimore.

[turtlem1969]

double check your tranny coolers also, had the drain plug on mine crack and about sent the boat under, only leaked when moving.

[sehord]

Pump your bilges dry then take off your engine hatch covers and take her for a ride. put someone at the helm and someone in the engine area. You'll be able to see where it's coming from. I recommend this for general maintenance all the time. Take a look at your engines while they are running. You may be suprised to catch a pully wobbling, a hose rubbing against a belt, a slow oil leak, smoke or water leaks boat motors operate MUCH DIFFERENT under a load then when run up at the dock.

[captainmaniac]

Agree with sehord... but be careful with hatches etc open while things are spinning.

No offence intended to aaron, but goretex is simply another brand of packing - it is not a miracle cure. It might have teflon embedded in it and be more slippery than standard flax packing, but in no way is it a 'poor mans version' of 'dripless stern tubes'. Any stuffing box will stop dripping if you tighten it too much - it doesn't matter what its packed with.

If you do the inspection that sehord recommended, try touching the stuffing boxes to get a sense of how hot they are (be very careful - hold your hand over top of the box without touching it first to make sure you donh't get burned). If the box is too hot to touch, not enough water flow. If it is touchable, its probably letting adequate water flow through.

[Big D]

I suggest you purchase a laser temp gun. It's great to have around a boat for making checks as noted above and a great diagnostic tool for the engine and genny, AC, you name it. They've really come down in price. In my opinion, keep the hands away. All it takes is a wake rocking the boat at the wrong time and it's all over. Use the gun and keep your distance.

[gettaway]

I run my F-32 at the dock a few times a month if I can't take her out, I add an extra line to the spring and stern cleats and put her in gear, and run at about 1000 rpm, one engine at a time, bring her up to temp for about 5 minutes or so then do the other.
this is when I check the stuffing boxes for the drip, a few drips minute while in gear, no drips while in neutral.

I can also check hoses, belts and water flow from the exhaust. I use a point and shoot "laser" thermometer to check the manifolds & risers for hot spots.
While I am sure this does not duplicat having herout and under a real load, it gives me a little piece of mind that I have at least looked at the running gear while under power.
if she is going to not start, throw a belt or pump or what ever, I would rather be in my slip than rolling around at sea.

[aaronbocknek]

i do that too once a week with the engines and genset. just like to make sure everything is running okay. it's my weekly diagnostic check, and yes, that also gets an entry in my maint. log book for my reference and for future buyers. besides, sometimes i just like to hear the sound of the engines running.... soothes my soul. and i too love my laser thermometer. during the winter, i also like to 'bump' the impellers (engines/genset) once a week so they do not 'freeze' in any one spot while she's winterized.