Bravo shift problem

[Mischief Managed]

I have an older Bravo upper gear case (0Lxxxxx serial number) that started shifting strangely over the weekend. It seemed like all of a sudden the shift cable became mis-adjusted and the drive would not go into forward gear until the throttle was advanced far enough to make it rev slightly above idle. At this point, it would clunk into forward and hold (no slipping). I adjusted the lower shift cable to make it operate normally (I moved the brass barrel toward the stern by rotating it clockwise on the cable sheath). It worked fine for a short time and then needed to be moved back again to make it shift correctly. Eventually, I ran out of adjustment and it started requiring too much lever throw to go into both reverse and forward.

I took the drive off today and cannot find anything obviously wrong with the lower shift cable. It moves smoothly and does not seem to have any slop in the pull direction. I can't figure out a good way to test it in the push direction, but I suspect that's the issue...

Anyway, since I have tools and spare parts at my disposal: I took the upper gears out of the drive and inspected the cone clutch, the inside of each gear (where the cone clutch engages), and shift mechanisms. They look perfect and have no visible differences in wear when compared known good parts.

Should I just go ahead and replace the shift cable? I cannot think of any other cause of this sort of issue. The cable is 8 years old and has at least 550 hours on it. It's an OEM Merc part.

Thanks in advance.

 

[alldodge]

Eventually, I ran out of adjustment
Should I just go ahead and replace the shift cable?

That's what I would do, sure looks like a lot of slop in the cable

 

[scoflaw]

Doesn't take much for the clutch to act up. It should have sharp edges with a dull black coloring. Revving until it engages with a bang is a classic symptom

 

[tpenfield]

You have the Merc Manual for the drive (right?) I would go ahead and put a new cable in as long as you have checked for the other more obvious causes. It may not fix the shifting, but it is worth a try.

Do you still need my Bravo Outdrive tools? I will probably need them back over the winter, but am OK for now. I got some days off coming up, so we can meet up once you have this issue behind you.

I'll send you a PM/email.

 

[Mischief Managed]

You have the Merc Manual for the drive (right?) I would go ahead and put a new cable in as long as you have checked for the other more obvious causes. It may not fix the shifting, but it is worth a try.

Do you still need my Bravo Outdrive tools? I will probably need them back over the winter, but am OK for now. I got some days off coming up, so we can meet up once you have this issue behind you.

I'll send you a PM/email.

I do have the manual.

I bought a new cable on my lunch break. Hopeful that it will be the fix. I was never going to remove an 8-year old cable for inspection and re-install it regardless, and inspecting the cable is the nex logical step. Guessing the sheathing is worn through somewhere in the engine compartment and the inner part of the cable is hanging out of it when pushed. If I'm right, I will coin the phrase "herniated shift cable" to describe it.

I will no longer need the tools at the end of the day today when I re-assemble the drive. Would love to meet for lunch again. Cheers!

 

[Mischief Managed]

Put the new cable in (it's SO much easier when you cut the end off the old cable, slide the old sheath off the old cable, slide the new sheath onto the old cable, slide the old cable out of the new sheath, and slide the new cable into the new sheath). Can't see anything obviously wrong with the old cable or sheath, which has me worried... I also put the drive back together and installed it. For the heck of it, I flipped the cone clutch over, but I saw no difference between the wear faces on either end. Shifted perfectly in my driveway. Water test on Friday. Fingers crossed. If it hoses up again, I'll put my spare drive on for the rest of the season and take my time figuring out what is wrong with it.

I built the funny-shifting upper gear case out of spare parts I acquired for little money, and it worked perfectly for 39 hours. Maybe I was just lucky for those 39 hours...

 

[tpenfield]

Aren't you supposed to be at work :noidea: You still have a job, right ?

 

[Mischief Managed]

Aren't you supposed to be at work :noidea: You still have a job, right ?

I work from home, so with no commute, I have a couple of extra hours per day to do this stuff.

 

[tpenfield]

:thumb:

 

[Mischief Managed]

Update: New cable did not fix the issue. When adjusted properly, I now have a roughly 1.5 second delay going into forward gear when the drive oil is warm, seems to engage at the normal speed, but really gently when cold. Reverse feels normal. I plan to swap the forward and reverse gears and also roughen up the female surfaces of the cone clutches on both side to extend the life of the parts. Any other advice? This is my spare drive, made for very little investment, so willing to try something innovative if anyone has a nifty idea.

FWIW, during the 35 hours that I have used this particular drive, it has never run low on oil, it has spent less than 5 minutes at WOT behind my 7.4 MPI, and the oil I used is the Quicksilver High Performance gear lube that I've always used in all my Merc drives over the years. I do not know the history of the parts prior to me using them to build the upper gear case, they came out of a badly corroded Bravo 3 I got on craigslist for really cheap money. I already had a nice upper gear case housing to put the parts in, so the purchase made good sense. I already got my money's worth out of the craigslist parts...

 

[alldodge]

Does your drive have the orange or silver garter springs in the upper gears. They where changed to orange in the later versions which are a smaller diameter. Timing marks aligned and other then that I have nothing more to think of

 

[Mischief Managed]

I don't recall any orange parts in the drive. It has what I call the "old style clutch" with the "7" stamped in it, so guessing silver springs. I aligned the gears correctly per the manual using the timing marks, and also made the nuts were on the bottom of the fork/cams assembly (though I cannot see what that would matter...). Fortunately, I am fond of this kind of work, it's truly a hobby for me. I just wish there was some obvious thing I could measure that would indicate exactly what wore out, this part of Bravo drives seems like more like magic than science or engineering. When I say the clutch parts look identical to known good parts, I mean really identical, same wear patterns, colors etc. That said, maybe my known good parts were just about to fail and the difference is in microns.

 

[tpenfield]

Yes, I did not think the cable was going to fix it. Is the next step to open up the outdrive? Is this the one you put together from parts on Craigslist?

 

[Mischief Managed]

Yes, I did not think the cable was going to fix it. Is the next step to open up the outdrive? Is this the one you put together from parts on Craigslist?

Yup. Sadly, I opened it up when I changed the cable, should have just roughened up the clutch mating surfaces while it was a pile of parts on my bench. Oh well, good practice for a potential way to make a little extra cash when I retire.

 

[Mischief Managed]

I'm getting really good at this, Took the drive off, drained a quart of gear oil, took the upper gears and clutch out and disassembled them, cleaned and roughened up the clutch cup surfaces on the gears, put the gears back in with forward and reverse swapped, and was about the button it up when my wife asked if I'd join her for a walk. Elapsed time was only 45 minutes...

 

[Mischief Managed]

Got the drive buttoned back up and installed. Tested it on the muffs and there is a massive difference in clutch engagement. This drive shifted very gently since I put it together, until now. Since doing my little trick to the clutch cups,it shifts very positively and with no delay. Will water test this weekend. Assuming it works properly in the water, I wonder how much more life this clutch assembly has in it...

It's awesome having a spare drive to experiment with, if you are in any way intrigued by this kind of stuff, I strongly recommend that you keep an eye on craigslist etc. for good deals on Bravo parts and tools. You can find ridiculous deals if you are not in a hurry.

 

[alldodge]

If this works and stays that way for some time, maybe we start sending all the drives your way for repair

 

[Mischief Managed]

Water tested today. Shifts instantly and very positively into forward and reverse. Amazing what a few tiny scratches can do. Long term? No clue...