DT115 Lower Unit Teardown

[ScubaSteve]

While waiting for some parts for my trim/tilt unit I've decided to do some maintenance to the lower unit. After shearing the heads off 3 lower unit bolts and having to pry the gear case away from the motor, I was able to open the water pump housing, impeller and gasket.

The oil seal around the drive shaft is still intact, but saltwater has done a number on the housing and some of the aluminum is missing around the seal. I also need to figure out what to do about the exhaust seal. The rubber insert that was once there is now completely missing.
I've tried to remove the screws holding down the bearing housing but I'm sure I'll end up using an ez-out on those too.

Looking at dj movers' thread (very helpful pictures and comments) it seems our 2 strokes have suffered the same ill-effects.
I notice my motor doesn't have the sub-water tube. I wonder if this was discontinued in the later models? Mine just has a cap over where the pickup would be.

Here are some pictures in its current state. If anyone has any advice or comments based on past experience I would greatly appreciate it.

[Solarman]

Not getting your pics, they just are not there for me.
What year motor do you have? Is it possible a previous owner removed the sub water pickup/ pipe?

Ok, just looked up your '99, dt115, gear case, and it shows the sub water pipe and parts for your unit? What do you mean ”it's capped off”?

Let us know.

[ScubaSteve]

OK got the bearing housing off. 3 of the bolts came out with an EZ out. Had to drill out the last one and re-tap the 6mm thread to 8 mm. I can live with it.

Let me know if the pictures work this time. Otherwise I can post a link to my photo bucket gallery. There is a cap over where the water tube would pick up the water. The rubber gasket and seal plate both have tabs that cover where the sub tube would have been. The pickup tab by the trim tab is also a full cover without any holes.

It looks like these parts are all original. Perhaps the water tube became an option in the later models? The gear case schematic shows Item 42 which is an exhaust seal assembly. Looks like these parts replace Item 13 and 14 which have a hole for the sub tube.

Waiting for the new housing and impeller kit to get here before I put it all back together.

[ScubaSteve]

Working on removing the propeller bearing housing. Fashioned my own puller but it just won't budge. Outer seal and retaining ring are shot so I'm weary of leaving the assembly as-is. Gonna add some penetrant and heat and let it sit under tension.

[Solarman]

Are you trying to pull the retainer under the prop? It takes a special puller. Do you know what you're doing? Are you trying to go into the gears/ transmission, and why? That has an oring seal, if you heat it up, you'll have to replace those seals.

And no, your pics still don't show. You should be able to add pics on the reply page.

[Moonlighter]

Pics are showing for me, on iPad anyway....

[Solarman]

No, none of the pics show. Steve, the retaining clip you can replace without pulling the prop shaft housing. If the shaft seal is not leaking, there isn't a need to pull it.

Let us know what is going on.

[ScubaSteve]

Not sure what to do differently with the pics.
Got the housing removed with the puller and some heat.
The outer dust/oil seal is completely shot and only a matter of time before it started leaking. The manual says to remove the whole housing to replace the seals so that's what I did.
Found a brand new assembly on eBay for a decent price so I have that on its way. Pinion gears and rest of the transmission look great. Looking forward to getting it all back together. Assembly pics to come (even though you can't see them Solarman)

[dj_movers]

Hi Steve,

***! That tube is missing??? That nice new plate that comes with the water pump kit should allow us to live with that salt water corrosion underneath. I just cleaned it good with a wire brush and mineral spirits.

I did not remove the bearing housing on mine. I noticed that the phillips screws had been replace with hex bolts on mine and that one of them was stripped. Mine is back together as of yesterday and working fine.

That rectangular area over the aluminum plate on mine could leak through to the water chamber. I'm not sure if that is a big problem, but I reapply a bed of silicone adhesive on mine.

Also, I replaced the rubber groummet that goes on the top of the water pump case housing (very cheap). The old one was cracking and brittle.

This is a very current topic with me, so if you have any specific questions, I will be happy to try to help as others have graciously done for me.

Regard,

David

[dj_movers]

***??? Really? All I said was W-O-W. Unbelievable...

[Moonlighter]

***??? Really? All I said was W-O-W. Unbelievable...

Yes, this site has some seriously weird things at times.

I was audacious enough to us the word g-o-l-d in a post evently and the same thing happened!

Sorry for any offence to those who are not **** plated!

See! It just happened again! Aaarrrggghhhhh!

[ScubaSteve]

I'm thinking *** is blocked for "whip it out Wednesday"??
No clue. I've gotten away with a lot worse in other forums.

Since the housing was all eaten away and oil seal becoming compromised, I decided to order a new housing from boats.net. Also have an impeller kit ready to install and other bits and pieces.

DJ...seems there was an option to seal up the water tube on the later models.
It shows both options on the schematic so I'll just leave it as is. I have the rubber seal and cover for the exhaust passage as well. Was going to silicone like yours but found the parts really cheap on fleabay

Will let you guys know when I start the re-assembly later this week.

[dj_movers]

Good to hear. So you found it on fleabay (not ebay)?

[ScubaSteve]

Haha yes I found it on ebay. Didn't realize fleabay is an actual site.

[dj_movers]

OK, thanks for clearing that up. I thought maybe I was looking at the wrong place!