Rebuilding Bravo 1 Upper
 

Hey all! First-time poster here. I recently picked up a 1993 Baja Islander 240, with the Merc 7.4L and Bravo 1 drive. Had a rather unfortunate problem arise on my second trip out, and I'm curious if anybody might have had a similar problem or any insight into what exactly had happened. After having the boat in the shop for a variety of projects, took it out for the first nearly-successful trip and had a blast. While idling back into the marina to the ramp, I noticed that my shift lever (Dana offshore controls) was in full reverse. Knew something was up, as I was still moving -> -> that'a way. Turns out I no longer had neutral or reverse, I was totally stuck in forward. After some comedy, got the boat out of the water, and once I got home started pulling stuff apart. Shifter to linkage looked good. I just had the intermediate shift cable replaced, so I had my suspicions there, but everything checked out. Alright, time to dig a little deeper. Drained the outdrive (lots of metal in gear lube as it drained) and pulled the back cover off the upper to look at the gears. Bingo! Gears still look great, clutch looks good, but I found the brass collar / bump ring on the bottom gear, the part with the clutch timing marks, was totally separated from the gear, ground down, and chunks of that brass are found throughout the drive. Some of that material transferred to the shift cam, too. So, I pulled the whole drive off, and then removed the driveshaft to pull the whole clutch assembly out. Took that apart, and found that brass collar was actually flattened out to the point that it's stuck on the clutch, it's opening is now too narrow for the clutch to separate from it. The rest of everything, driveshafts, housings, lower, etc. all look totally fine, so I bit the bullet and ordered a complete new upper gear assembly. Still waiting on parts, but I have every expectation that everything will be great once it's reassembled. I am following all instructions from the mercury service manual and have ordered updated parts as necessary.

So, first off, any ideas as to what the heck could've happened, or what caused this weird issue? My only thought is that if someone had pulled the driveshaft, and not properly aligned the clutch timing marks before reassembly? Or worse yet, aligned them + to + and - to -, completely the opposite of correct? Seems to me that could cause the shift cam to come into undue contact with those brass collars?

Secondly, if anyone has any hot tips on reassembling the drive, I'll certainly take them. I'm reassembling exactly as I disassembled, and following the service manual for every little bit, properly lubing, sealing, and loctite-ing everything along the way... But any words of wisdom from someone experienced is always appreciated!

I'd upload photos, but I haven't been here long enough for the forum to let me... :signs036:

Tried to add photos. Still a no-go.

Did you buy the gear upgrade kit?

Need to post 10 times before you can upload pics

Finding metal when draining, going to need to open the lower to flush

Yeah, I bought the upgraded gear kit that changed in 2001, as well as the corresponding thinner shims specified in Mercruiser Service Bulletin 2001-17. This is really why I bought the whole new assembly; I was afraid of buying used and piecing together what might’ve ended up being a mix of original and updated parts.

But I didn’t explore any X or XR upgrades, if that’s what you meant.

Yep, I’ve got the lower torn off and apart too! Everything there is looking good too, just cleaned out all the shavings.

Alright, racked up enough posts for pictures! So here's what I was talking about.
https://cimg0.ibsrv.net/gimg/www.off...1fde8c37d.jpeg
My one pic of the boat so far!
https://cimg1.ibsrv.net/gimg/www.off...0d94fd8c4.jpeg
Brass timing collar separated from gear, and ground down
https://cimg8.ibsrv.net/gimg/www.off...1654261db.jpeg
Brass timing collar stuck on clutch
https://cimg7.ibsrv.net/gimg/www.off...e5a36e01e.jpeg
https://cimg9.ibsrv.net/gimg/www.off...885abd0c5.jpeg
Brass material from timing collar transferred to shift cam

What's the cost of this vs. a SEI whole bravo drive w/a 3 yr warranty?
My drives are approaching 900 hours and shifting is becoming more difficult. and I have paint issues on them, and I think both lose a bit of drive oil (maybe 5oz each over a season of 100 engine hours).

so, at some point, I'm thinking I'll throw 2 new SEI Bravo drives on it and sell the old drives for parts.

Don't know what caused it but looks like it got pretty hot

Was new style lower shaft installed with new gear set?
HP gear lube?

Otherwise I have nothing, could be stuff happens

Thats the kit I’m talking about, you’ll need a puller that will be capable to get the driven gear races off of the tower in the case and on the top cap, and a driver to position the new, narrower races on the tower( merc sells both)