I know of many early -mid 90's series of bravo ones that have been abused beyond thunderdome that have outlasted the engines infront of them. It was like they felt a imminent threat on the horizon with the new at the time stuff coming down the pike from the vp boys and took it up a notch with the premium line than rolled it back when they got comfy . Maybe it was the chinese trying to hoard up aluminum and steel

I bought my '96 Baja 272 with 700+ hours on the clock, junk 7.4mpi, and no known history. The drive still seems solid and a visual inspection of the gears shows no problems. I'm not saying that it won't grenade the next time out, but this far has held up.

Hello All,

Got the drive apart yesterday and as promised, I'll fill you in on the details. Good news is, everything - gears, bearings, races, clutch - all look pristine. At 440 hours, the gears have a slight discoloration at their exact point of contact with their mating gear, which looks to be textbook shape and size. What happened? Well it seems the pressed-on brass ring on the top driven gear "fell off" and wouldn't allow the clutch to shift out of the last gear engaged (reverse). This part doesn't appear to be available from Mercury - it comes pre-installed on a new upper gearset. Now from my inspection, it looks like this ring was pressed on along with some kind of Loctite-type adhesive. There is definitely residue inside the ring that's not oil. A buddy of mine has some really heavy duty, industrial strength, not-sold-to-the-public loctite type stuff and a big giant press. I'm thinking, clean out the ring thoroughly with a brass wire brush & solvent, apply thin layer of the adhesive, press back into place and done. It's worth noting that just before the failure, I was running the boat wide open for maybe 30-45 minutes. I have a drive shower that seems to work well (there's a hurricane of water back there while running on plane) but it's guaranteed the drive was up at it's operating temperature... whatever that may be. I can say then when I jump in the water after a hard run, the drive case (which I like to feel for temp) is only warm, maybe 100°-120°F. I mention this because the different expansion rates of the steel gear & brass ring surely must have played a part in the separation failure.
Now for the bad news... In my blinding excitement during disassembly, I completely forgot to mark the gears for reassembly. The brass rings actually serve part of that purpose, as shown in my last pic, but that will do me no good since the ring has separated from the top gear. Plus I totally forgot to mark the pinion too. The only upside is that I've kept the bearings/races where they belong and facing the right direction. How critical is it that I reinstall everything so every gear tooth is mated back with it's corresponding tooth? As I said above, there is no chipping or damage of any kind to the gear teeth, only a slightly visible, normal wear pattern. Will this thing grenade when I put it back together out of correspondence? I guess I'll be finding out, since it's not possible at this point to reassemble it exactly as it was.
Brian

Make sure that area where the ring goes on doesnt have any cracks.
A matched thick floor single gear from a set is usually pretty cheap compared to being stuck in gear somewhere

Get used to that blower motor chewing up bravos.lots of torque mid range getting/staying on plane at the lower speeds.
I too have reg.bravos and wonder why a drive not really rated for 525hp was placed behind that engine?

It should be ok if you can keep the Brass Ring on the gear, call Max Machine in Lake Havasau, ask them if it will work, they are very good at building drives.
It most likely will need to be checked for correct gear backlash and bearing wear with those hours.

Quick update:
Drive is back together with original parts. Inspection showed no cracking, pitting, chipping on anything inside. I have a concern though, the backlash in the driveshaft housing gears is between .003 - .004" ...does this sound normal? I mic'ed the thrust bearing shims and they correspond to the stamps under the rear cover. I don't really see any other adjustments here. Otherwise, it should be good; I plan on a short trip to shake it down and then drain the oil and visually inspect afterward.

Thats a little on the tight side, .010 is normal, did you check lash on both forward & reverse , and how did you measure it,

I'm embarrassed to say, since I wasn't sure how to get an accurate reading. The top cover should be installed IMO since this is the upper bearing carrier. And the u-joint obviously must be installed, so I set a dial indicator up on the drive housing and checked the play at the u-joint. So I guess what I measured was the play between the pinion and both the driven gears.

There's a couple of tools that are used to check backlash,

One is basically clamps on to the eccentric ring to allow you to hold the gear in place,
The other is a dummy input shaft that you install on to the pinion gear, then there's what they call a flag which is basically a hose clamp with a tab welded on to it with a line scribed on it..this goes over the dummy shaft....you line up the dial indicator to contact the line on the tab, hold the driven gear, rotate the dummy shaft at take the measurement, then move the clamping tool the opposite driven gear and repeat the process

Make shire on final assembly that you line up the plus and the minus, never plus-plus, minus-minus