Rebuilding Bravo 1 Upper
#1
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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...
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...

#5
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Originally Posted by JaayTeee;[url=tel:4875668
4875668[/url]]Did you buy the gear upgrade kit?
But I didn’t explore any X or XR upgrades, if that’s what you meant.
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#7
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Alright, racked up enough posts for pictures! So here's what I was talking about.

My one pic of the boat so far!

Brass timing collar separated from gear, and ground down

Brass timing collar stuck on clutch


Brass material from timing collar transferred to shift cam

My one pic of the boat so far!

Brass timing collar separated from gear, and ground down

Brass timing collar stuck on clutch


Brass material from timing collar transferred to shift cam
#8
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From: USA, PA
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.
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.
#10
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From: ankeny,ia.
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.
But I didn’t explore any X or XR upgrades, if that’s what you meant.



