qaberdeen

Having a problem with shifting to reverse...

i know you're not suppose to shift when the boat is not started with the bravos...but if i try to shift in reverse when boat is not started, if feels like something is about to break..but i get forward position no problem..

the other day when i was checking the alternator, with boat started on trailer, i dink when i tapped the throttles, i not sure but i dink in might have jumped into gear, but it was not a loud sound but i did hear something.. now when i try to get reverve, the shifter cant move back at all when not started, but when i start the boat, i can get reverse with the shifter, but the prop shaft is not engaging..but it does spin forward, i did try to spin the barrell, in different positions, but i did not play around with for long..

any i idea where i can start looking...

thks Q

Mr Gadgets

Q,
The bravo uses bump rings on the driven gears. There is a high and a low side. They are timed so that the high side and low side are opposite each other. When the gears are spinning the space between them moves up and down. When you shift the drive with the input shaft spinning it will start to push the cone into that gear, engaging it. When you shift back to neutral, the bump ring knocks the cone out of the gear when the cam on the shift fork hits the bump ring.
Now when the input shaft is not turing, the space could be close to fwd or rev gear. It will sometimes pop into one gear, but not the other because the bump rings are aligned so the space is closer to one gear than the other. Trying to force it against non turning bump rings will break things..

You say, when the motor is running, the drive will go into Rev and Fwd, but the propshaft does not turn in Rev, just Fwd. Does the shifter feel the same going into each gear? Do you hear the same noises when going into each gear? When you were checking your alternator and it possibly slipped into gear, what rpm was it turning at?

To look for the problem.. first I would remove the cable with the barrel nut. Start the motor and shift it into neutral. You should be able to feel the detent centering the shift linkage. Now line up the barrel so I slips back into the holder. Try shifing fwd, and rev.. check the feel and sound.
If it still does not engage. Then shut it off, drain some fluid and pull the back cap. Look at the linkage, make sure it is intact. You should be able to spin the motor over, with the kill cord pulled and not start the motor.. if you try shifting it, and it goes into gear, you wont be able to turn the motor over with the starter, the neutral safety switch will not allow it.

That is the theory behind it all. Becareful when you are working on it. I suggest being on the trailer at the ramp and try shifting and aligning the cable. If it goes into rev, you are good. If not take the back cap off after draining and check it, but not at the launch..

Hopet that helps.
Dick

qaberdeen

Thanks D, Hopefully i can get to it this weekend... I think i was probally running about 1300- 1500 rpms i'm guessing...when started it feels the same going into forward and reverse.. the prop shaft spins forward, but not backwards..theres no grinding or anything..which back cap did u want me to pull after draining the oil..


thks again Q

Mr Gadgets

On the back of the drive, the cap with the three bolts. It has the detent ball in it. You will be able to see what is going on, once you pull it. If the floor of the gear is pushed out, then the pinion gear/input shaft needs to be removed, then the top cap and shift linkage, then you can pull the gear stack and seperate it. Then you will be able to check it out completely.

Hope that helps.
Dick

qaberdeen

ok.. I had a chance to get to the boat, but just wanted to double check everything over.. here's whats happening.... when is started on trailer, i was able to shift forward with prop shaft rotating, shift neutral and prop shaft stops moving, but when i shift back into reverse nothing happens..prop shaft remains still.. i tried different settings with the barrel, with no luck getting reverse... i did not check the back cap as yet either..just did not want to mess anything up further...

but when i first noticed the problem.. i could shift forward when boat was not started, shift neutral no problem, but i could not pull the shifter back to get it into reverse.. it felt like something was blocking it and the shifter would not move back at all.. but when it's started it moves freely forward and backwards.... any ideas..

Mr Gadgets

The bravo drive is not suppose to be shifted when the input shaft is not turning. The bump rings have a high an low side. The two gears are timed so the space stays the same, but moves up and down. When at rest and the space is closer to one gear than the other, it may shift into that gear. But trying to shift into the other gear it will hit the high side of the bump ring and will not move. Spin the input shaft and it will shift.
Couple of things can be happening. on the older style, thin floored gears there is a thrust bearing with a cover over it. The cone spring rides on it, and that cover will crack. Loose pieces cause it to not seat the cone into the gear. Or the floor could be broken, not likely in reverse. How old is the drive, what does the serial number start with? If is OL or older, it has the thin floored gears. And a good bet the cover for the thrust bearing is cracked.

Hope that helps
Dick

qaberdeen

Thks Mr. G..

I had one of the local mechanics look at it...and i dink they just used the setting tool and all is well...but hopefully, i can get the boat over this weekend and see if indeed all is well..lol

thks again..

Q

YellowFever

Did you ever find to problem to this?