I just changed to another drive (used, but supposedly in perfect running order). The drive seems to work fine, accept for a complete lack of any signal from the speedo.

However, I've now got a slow but consistant leak into the bildge. It doesn't seem to happen any worse while running, and in fact only occurs when the boat sits. I've stuck my head down around the drive on the inside and felt all around and can't find a source. The only thing that has changed since the leak started was the new drive.

I don't seem to be getting any water into the drive oil, and I followed all the instructions carefully during the change. What is the most probable leak path at this point? When I take the drive off, what should I check for?

thanks

The rubber bellows around the drive shaft/u-joints is either not on correctly or leaking due to deterioration or damage. Did you replace it when the drive was off. If not, you should. What drive is it? Some have other passageways through the gimbal that water can leak through.

You need to fix this before your boat ends up on the bottom. A ripped gimbal bellows will let in more water than most doal bilge pump setups can deal with.

Sounds like your speedo pickup hose from the drive is not connected..........

Speedo Pickup
Gimbal Bellows
Shift cable bellows

It's a bravo1 drive. I didn't take the entire assembly off, just the drive itself. the gimbal and housing and any existing belows stayed in place and were not moved or altered in any way. Not sure what could have changed there.

The speedo pickup is attached both inside as well as on the drive.

Probably a coincidental occurence. Or you could have snagged a partially-deteriorated bellows with the input shaft/u-joint. Bellows is usually the most common spot.

other than the three O-rings, there's nothing in that interface between the drive and gimbal that needs to seal, correct?

usually the shift cable bellows leaks into the boat. The u-joint bellows fills the cavity but the seal that rides on the driveshaft pretty much seals the water from coming in the boat. Try trimming the drive all the way up and turn the steering all the way to port. if it gets worse probably shift bellows. Could also come from the trim hose manifold outside the boat or exhaust pipe horn if you have corsa,captains choice or other switchable exhaust not a block off plate on the transom asm.
good luck

A friend of mine had a very similar problem and it turned out to be the shift cable bellow. Is there any chance you tilted the bellhousing up higher than its normal range of travel?? Could have split an ailing boot!

When my drive bellows was bad I had water in the bilge. If that is the case I would recommend (from my limitedexperience) going ahead and replacing the Gimbal Bearing because it is probably now prone to premature failure. My symptoms were similiar to yours, water whether running or stopped.

I tackled mine myself, and if you are mechanically inclined at all you should go for it.

Swivel seal is also a leak culprit - I now have one leaking - symptoms are that it takes on water when it is splashed. For example if we are anchored and it is getting wet at the top of the "helmet", or when I come down off plane. I find water on the top "shelf" of the gimbal inside the boat directly beside the steering arm, and in my case I found salt residue after it dries)