Outdrives comming up while in reverse??

[blucherb]

I have a 1989 Carver with volvo penta engines and inboard outboards. I dont know much about the outdrives and am wondering whats wrong. The boat runs fine underway, but when i put the boat in reverse, the outdrives pop up out of the water and i cant go in reverse. The wont go back down untill i put the boat in forward and i manually put them down. I have heard thats its because the outdrives need to be clean, but i have cleaned them several times. any ideas

[KnottyBuoyz]

Depending on which model outdrive you have there is a mechanism called a "reversing latch" or "reversing lock" that is engaged when you shift into reverse. This latch is designed to hold the drives down against the backwards thrust that is lifting your drives. These latches wear over time. Depending on the amount of wear they may have to be replaced or refurbished. Sometimes marine growth can affect their performance but not likely. Sloppiness in the shifting cable and linkages within the drive can cause similar problems. Sometimes a little tweaking and tightening can fix this problem. If you post the model of your outdrive I can locate the appropriate part numbers required for the fix.

Rick

[blucherb]

how would i go about finding out what type and model number my outdrives are?

[marshmat]

Should be written on the outer housing... if the original decals are worn off, look for a serial number plate on the inside of the transom fitting; sometimes it's also on the side of the outer part of the transom fitting.

[KnottyBuoyz]

http://www.marinepartsexpress.com/vp_engine_finder.htm

[longliner45]

should have lockdown pins at the transome

[gonzo]

The reverse latch mechanism works only with the drive trimmed in. Many operators trim the drive up while running and forget to trim down to reverse. This causes it not to latch or even worse to partially latch and damage the mechanism.

[Raftman1979]

Be careful, though. Once you get this thing to lock in the down position, it is no longer safe to operate in shallow water, or where there may be submerged objects or wing dams just below the surface. With it unlocked, the out-drive can pop out of the water if you run aground in shallow water or hit something. My Bass Tracker's 40 horse Merc outboard has no locking pin. I can only idle in reverse or it'll pop out of the water. But it's an acceptable trade-off for not having my engine rip the transom off the boat when I hit a sand bar at high speed.

[grady]

I don't know about volvo's but I have experienced this problem with an omc cobra stern drive. That was caused by a hydraulic line from the trim pump to the ram on the outdrive. The leak allows the ram to compress upward under the force of drive being operated in reverse.

The two lines from the pump (one for extending the ram,[down] and one for retracting the ram [up]. If the one used to retract the ram has a lost of pressure it can allow manual compression of that ram which would cause the drive to lift out the water in reverse.

The lines terminate at the transom sheild via a coupling then are picked up on the other side by short hoses to the rams.

I hope this helps

Best of luck.

[grady]

Just noticed the time date stamp on the original thread. Sure hope you have gotten to the root of the problem by now.