Bravo 3 Shift Adjustment . . .

[tpenfield]

Hello Everyone,

The starboard engine started acting up today on the way back to my home port after a day-long outing. It would not go into gear once in the harbor and at no-wake speeds. (Bravo 3 outdrive) We had to stop a few times for traffic in the channel, so I was in and out of gear a few times. Then after a while, nothing from the starboard engine. :facepalm:

If I tried to force it (which I did once) , the engine revs would pick up before it went into gear, causing a jolt when it finally engaged. It has done this a few times in the past year or so, but the problem then goes away.

I navigated to the dock on the port engine.

Upon leaving the dock, the starboard engine would now go into gear no problem, as if nothing had happened :noidea: . I'm assuming it is an adjustment and I probably need to get the adjustment tool, but I thought I would check in with the experts before I get in too deep.

Thoughts?

FWIW - I have the crappy Quicksilver controls . . . thinking of getting the high performance controls with separate shift and throttle levers . . .

 

[alldodge]

I think its glazing of the upper driveshaft

 

[tpenfield]

I think its glazing of the upper driveshaft

Tell me more . . . :noidea:

 

[alldodge]

There are several threads but the clutches and shaft get glazed and start hanging/binding. Some take them apart and take 400 sand paper and get them going again. Others just replace shaft and clutch. The shaft is item 28

https://www.mercruiserparts.com/bam/subassembly/30971/952/70

 

[tpenfield]

There are several threads but the clutches and shaft get glazed and start hanging/binding. Some take them apart and take 400 sand paper and get them going again. Others just replace shaft and clutch. The shaft is item 28

https://www.mercruiserparts.com/bam/...y/30971/952/70

Thanks alldodge I'll look up those threads. Probably will have to deal with it for the season, as it would cost a small bundle to take the boat out and put it back in again ($330 each way) + what ever the cost of repairing the outdrive (parts/supplies).

Do you think running some sort of solvent in the outdrive gear oil would help remedy the 'glazing' ?

. . . or . . . Maybe best to plan a little bit of outdrive work over the winter :noidea:

 

[tpenfield]

I just read through a few threads that I found here on iBoats . . .

So this 'glazing' thing is preventing the clutch from moving up/down on the shaft as smoothly as it should ? Therefore, with a little bit of extra RPM, the clutch then slides along the shaft :noidea:

Just trying to get a picture of the gear action and the cause of the clutch hanging up.

Sounds like Mercruiser does not recommend the abrasion technique (400 grit or valve lapping compound), but others say that it works.

Specified repair is to replace the clutch/gear set . . .

 

[alldodge]

Morning, I wouldn't recommend any kind of solvent, only see more problems from it

So this 'glazing' thing is preventing the clutch from moving up/down on the shaft as smoothly as it should ? Therefore, with a little bit of extra RPM, the clutch then slides along the shaft

Yes, and the lapping makes it smooth enough to shift. I also agree with Merc, and all your doing is polishing things so it will slide easier. There is wear so the gears **** a slight bit, so lapping will work but won't last.

The correct fix is new shaft, and in your case new gears. The drive shaft was replaced with newer design and if you look up your drive the gears are NLA. Looking at the latest drive serial number series, it shows the same shaft and the new gears.

 

[tpenfield]

OK - thanks. After I posted my last comment I was thinking a certain amount of wear would allow the clutch to become cockeyed and bind on the shaft as it needed to travel up or down.

1,000 hours on these puppies, so probably time for some rebuilding.

We are out in the boat again today and the shifting initially worked fine, but while anchoring it would not shift into forward. Still does reverse thouGh.

 

[tpenfield]

And then after anchoring for a few hours. . . it shifted fine :facepalm:


Very much hit-or-miss at this point.

 

[alldodge]

Did ya get my email?

 

[tpenfield]

Did ya get my email?

Yes, sorry for the delayed response . . . Thanks for the info. :thumb:

Now to see if the outdrives can make it through the season as they are . . . :noidea:

 

[tpenfield]

BTW - you mentioned that I would need to replace the gears as well as the clutch and shaft. Not sure why the gears, unless they prove to be worn. Is there a old version vs. new version parts compatibility issue?

I have the 1.81 gear ratio. if that matters.

I replaced the bearing carriers on the LU a few years ago. Is there anything I need to be concerned about in the lower units? or . . . "I.I.A.B.D.F.I." :noidea:

 

[alldodge]

I.I.A.B.D.F.I.

Had to look that up

From my reading of the manual, drive history and Bul 2001-17 I'm finding things should be replaced as a kit. Might have missed something, just what I'm finding so far

View attachment Bul 2001-17 Bravo Gear change Bullentin.pdf

 

[salty3rd]

Hi Ted,
I had the same issue with one of my Bravo 3’s, I lived with it last season, kind of a PITA-couldn’t trust it when docking. I was going to try the polishing route, but opened it up and decided I wasn’t gonna take any chances. I brought it to a good Merc mechanic and he installed new clutch and gears for about $2700. It’s been running beautifully since. PM me if you want his name, I highly recommend him. He is on the South Shore..Bill

 

[tpenfield]

Hi Ted,
I had the same issue with one of my Bravo 3’s, I lived with it last season, kind of a PITA-couldn’t trust it when docking. I was going to try the polishing route, but opened it up and decided I wasn’t gonna take any chances. I brought it to a good Merc mechanic and he installed new clutch and gears for about $2700. It’s been running beautifully since. PM me if you want his name, I highly recommend him. He is on the South Shore..Bill

Thanks Salty :thumb:

I'll probably fix it myself and hoping I can get through the season ( Oct 1st). If it has trouble shifting on every outing this hit-or-miss will get old fast.

Also looking into the possibility of buying a used/rebuilt B3 and doing a 'hot' swap to keep me going through the season. I may be able to get my boat hauler to give me a break $$$ on a haul out/in for a repair. Seems like for $2500-3000, I could grab a used B3 off CL.

 

[tpenfield]

Quick update on my research . . .

I consulted with a friend who has some good experience rebuilding Bravo outdrives (also a member here on iBoats) and he gave me some advice regrading the sanding/lapping approach, if I were to go that route. One thing he mentioned, if I choose to rough up the glazed clutch surface, was to flip the gear set upside down upon re-installation.

I assume this would mean that the side of the clutch that used to be used for reverse would now be used for forward and vice versa. Since forward is generally used a lot more than reverse, I would then be using the less worn side for forward. It sounds like a good solution . . .

Thoughts?

 

[tpenfield]

Update . . .

Bringing my thread back to life, as I am now taking the outdrives apart to fix the clutches. I am doing the 'unapproved' approach of de-glazing the clutch surfaces.

Anyway, I got the outdrive apart . . .
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I am at the point where I need to take the top gear off the shaft to expose and remove the cone clutch.


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The service manual says to press down on the top gear and remove 2 retainers and then the collar that holds the retainers.
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I cannot see that pressing down on the gear is actually doing anything that would allow the retainers to be removed.

For those who have experience in this sort of disassembly, is there a trick to doing this?

Thanks in advance . . . the boat has been tag teaming me today.

 

[tpenfield]

The only thing that I notice is that the cone clutch is engaged in the 'top' gear, but I'm not sure how to release it back to a 'neutral' state. . . if that matters

 

[alldodge]

Just noticed this. The system doesn't provide old thread notifications via email, only newer ones

In any case, looking a both Bravo manuals, they both say the same thing. So I would say, your gears may be frozen up

 

[tpenfield]

I did it !!!
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I just needed to get the gear set on my bench so I could get a bit of leverage on it. Essentially I had to push down on the top gear with a fair amount of force until it 'shifted'. It all was easy from there.