Gear oil (I think) leaking from lower unit

[cchamp]

So, went to take the boat out today and same seepage is occurring. I'm assuming that means I didn't seat the gasket properly? I was very careful, didn't over torque, and am surprised that the leak persists.


On another note, about 10 minutes into my trip today I noticed the boat was running a bit hot when I pushed it. Normally runs about 170 (according to my gauge) and was pushing 195. I assumed it was the impeller I installed, that maybe I did it incorrectly. Cut the boat, did some fishing, went to start it and absolutely dead (no accessories etc). After some inspection I noticed the red cable attached to the starter was completely snapped where the O-ring attaches to the fuse. Luckily was able to cut the cable and reconnect it to the screw BUT a few questions:

Will running the engine at 190-200 for a short period of time do any damage? After the cable was reconnected the boat ran fine and kept its usual temperature.

Last year I had a broken starter bolt, now this year this wire snaps. Its an old boat so its possible this is normal...but is it possible that something else is causing these issues? Rough start/jolt etc?

Crazy day! Thought I was going to be stranded for a bit there.

 

[achris]

It's more likely the engine wasn't running hot... If the engine was running when the cable broke, then the alternator was the only thing providing power, and without the battery connected for a voltage reference, its output would have gone very high (up to 20v)... Those gauges are just a simple voltage divider, and a higher supply voltage would generate a higher reading for the same engine temp....

Chris....

 

[cchamp]

It's more likely the engine wasn't running hot... If the engine was running when the cable broke, then the alternator was the only thing providing power, and without the battery connected for a voltage reference, its output would have gone very high (up to 20v)... Those gauges are just a simple voltage divider, and a higher supply voltage would generate a higher reading for the same engine temp....

Chris....

Thank you. I didn't notice any other indicators of hot running.

Can you confirm that if I'm seeing gear lube again from the water intake vents that I must not have secured the impeller gasket properly? Is there any other possible source for that leak?

 

[achris]

Did you pressure test the drive before refilling with oil?

 

[cchamp]

Did you pressure test the drive before refilling with oil?

I honestly wouldn't even know where to begin with that, so no. Did not. Don't think I have the equipment needed to do it.

 

[cchamp]

On that note, if the pressure test is simply done to indicate x/y/z seal should be replaced just tell me which ones are at issue and I'll replace them all. This boat is 17 years old and I'm sure they are all game.

 

[achris]

http://forums.iboats.com/showthread....4743&p=3556035

That should help you. And yes, at 17 years old, seals get a bit 'tired'... Most are dead easy to replace, some a bit trickier..

 

[Rick Stephens]

Still a good idea to make up a pressure tester. I made one with a hunk of 1 1/4" PVC pipe, a few fittings, a schrader valve and a suitable pressure gauge that cost me about $12. I then stole the metal fitting off of a lower unit oil pump, the kind you get to fill your drive with oil and voila, I had a pressure tester. There is a thread on building your own in the Adults Only section of this forum. If you are changing all your seals you will need to pressure test the drive to be certain they all sealed up properly.

 

[cchamp]

Thanks all. I think I can build one of those. Anyone have a seal kit they'd recommend? I think I'm just going to take it apart and do the whole damn thing. I've got a 2003 mercruiser 3.0 with an alpha one gen 2. Can get serial number if needed.

 

[achris]

For things like bellows and seal kits, I only use OEM. I've used non-genuine in the past, and always regretted it.

Seal kit for the top housing is 26-88397A1. For that you'll need the special spanner to remove and refit the front cover.. and a torque INDICTAOR to reset the preload for the bearing pack (see my videos).

The lower housing is just the seal under the water pump you have already replaced, the shift shaft seal and the bearing carrier seals (propshaft) and O ring. The bearing carrier needs another couple of special tools to remove, and as it's not leaking, leave it alone. I usually just replace the whole bushing assembly for the shift shaft (it has all the seals and O rings already installed), part number 23-815921A20. No special tools required.

Chris......

 

[cchamp]

So, good news and bad news. The good news is I was able to put together a little pressure tester based on the example from Ziggy in the link above, used a bike tire valve and was able to give it a go this afternoon. Only have a plastic connector from one of the gear lube pumps but hopefully it will hold up long enough for my limited needs. Total cost about 15 bucks.


Bad news is when I gave it a go it barely held any pressure and let out a pretty god awful squeal that sounded like it was coming from the upper unit. I was hoping the leak would be in the lower unit since it appears to be a much easier job...but looks like I'll be doing the upper unit. Ordered the parts, looks like it will be about a week before they arrive.

Video of the pressure test/sound it emits: https://www.youtube.com/watch?v=XGACxKuKc8U

 

[achris]

Use soapy water to find which seal is leaking...

 

[cchamp]

Use soapy water to find which seal is leaking...

OK. Will do.

 

[cchamp]

So, replaced the shift cable bushing and double checked my installation of everything else. Now its holding pressure and I think I'm good to go. Doing bellows/gimbal bearing/shift cable as well and hope to put it all back together this weekend. Getting close to getting back on the water (crosses fingers).

 

[achris]

Were the gimbal bearing and shift cable damaged?

 

[cchamp]

Were the gimbal bearing and shift cable damaged?

Gimbal bearing rotated freely but was greasable and I wanted to go to a sealed bearing. I also think it may have never been replaced (boat has been in family for about a decade). It bent my puller tool when I tried to remove it initially and I had to go rent a slide hammer from a local auto parts store. Took A LOT to get it out, but it eventually came. New one went in easily and I aligned the engine, was slightly elevated in the front.

I clipped the little nut on the end of the shift cable to remove the bell housing so I could have easy access to everything. Also doing trim senders, water hose, gear lube line, bellows etc. Honestly,shift cable is the one thing I'm a bit hesitant to tackle. Seems ripe for problems.