Bravo 3 lower unit blown seals and corrosion

[gcarmich]

I pulled my boat out of the water last week and noticed an oil leak and severe corrosion on my Bravo 3 outdrive. The oil was leaking through the prop and at the gear case and when I pulled off the lower unit, I could see oil coating the drive shaft. I got the carrier assembly out yesterday and it also has severe corrosion (see pic). When I drained the gear oil it was black. The lower unit obviously missed a scheduled maintenance or more...

I think I can fix the corrosion on the outdrive with JB Weld or Marine-Tex after cleaning it up a bit. I can replace the shaft oil seals, carrier assembly, and o-ring on the drive shaft.

Questions: Are there other components on the lower unit that I should check/replace? Should I pull the gears out of the casing for inspection?

Thanks, Gil

 

[alldodge]

Need the manual, and if yours pre 2000 need manual 11 and 2000 on manual 28

Use seals for 2000 on because they work better and do fit.
1 each Small inner seal 26-8M0033407 (replaces 2 each lip seals)
1 each Large outer seal 26-861694 (replaces 2 each lip seals)
Dimensions 3 - 3/8 OD, 2 - 1/2 ID, 13/16 wide

Will need to check gear lash and may need to re-shim
This thread may help some
https://forums.iboats.com/threads/looks-like-im-getting-into-bravo-outdrive-repair.617342/page-2

 

[tpenfield]

The replacement bearing carrier has the seals installed, so you should just need the carrier assembly. Last time I bought them, they were $400 ish.

How's the rest of the drive?

 

[gcarmich]

Sorry - forgot to mention that it is a 2005. I have the digital manual.
I was checking out the engine yesterday and noticed that the lube reservoir had oil on the outside of it - it seems the oil might have been forced out of the cap? Maybe the gear oil got under pressure and pushed out where ever it could?
I've attached pictures of the lower unit.

I'll check into how to check gear lash - looks like I might need some more specialty tools...

Thanks, Gil

 

[alldodge]

The lube comes out the cap when the valve cap goes bad.

The inner shaft doesn't look to good, hope it cleans up

I would replace the inner shaft seal as well

 

[gcarmich]

The lube comes out the cap when the valve cap goes bad.

The inner shaft doesn't look to good, hope it cleans up

I would replace the inner shaft seal as well

I had oil coming out through the prop and the gearcase so I was thinking both seals needed replacing, I guess I'll also need an o-ring for the drive shaft and a cap seal. I think the shafts will clean up - I haven't touched them yet.

 

[dubs283]

Replace carrier assy, may or may not come with a prop shaft seal and o ring. Replace inner shaft seal as well. No need to worry about gear lash as long as the gears and bearings are being reused. Definitely need to remove both prop shafts and clean/inspect seal areas.

Never seen a relief valve on a monitor cap fail but have found cap gasket/seal in more than one bilge. No seal will cause the monitor to overflow due to pressure from drive operation. Seal is about 1.5" diameter, 1/8" wide rubber ring

 

[alldodge]

As Ted said in prior post the carrier comes with seal already installed, along with o ring.

There a many threads about the cap valve seal failing and belching lube out over the net. Mine also failed and did the same. Bought a complete bottle and just replaced the cap, all good after. Can post the thread if needed

 

[alldodge]

Note the difference in the valves

 

[dubs283]

As Ted said in prior post the carrier comes with seal already installed, along with o ring.

There a many threads about the cap valve seal failing and belching lube out over the net. Mine also failed and did the same. Bought a complete bottle and just replaced the cap, all good after. Can post the thread if needed

Maybe oem but that could have changed

Got it, your relief valve failed. Just saying I've personally never seen one fail, and I've seen a lot of monitor caps. I've found gaskets for the cap in the bilge more times than I care to remember, clean up isn't much fun. Wanted to let OP know there is a more common (IME) failing and possible for them to locate said seal if that is the case.

Would also mention it's possible the float assy seal at the bottom of the monitor has failed, complete bottle assy replacement is required for this, cap not included with bottle assy

 

[alldodge]

I've found gaskets for the cap in the bilge

Please shows us where the gasket cap gasket is located

 

[dubs283]

Please shows us where the gasket cap gasket is located

I hope you're kidding

But in the picture you posted its the black seal/gasket seated in the cap, it seals the cap to the top of the threaded neck on the bottle

 

[alldodge]

I'm not kidding, there is no gasket in the pic of either one old/new

 

[dubs283]

I'm not kidding, there is no gasket in the pic of either one old/new

It's okay, fella. You don't have to believe me but I can see the seals in both caps you have in the posted pic. Right hand one is a bit clearer and shows the witness from the top edge of the threaded neck on the bottle. But again believe what you like.

I'll chalk this one up to the difference between an armchair and a real/ experienced mechanic. Sleep tight