Reverse works at low RPM but ‘slips out’ with throttle

[ShipShow]

Hello all,
New member but long time boater. Recently purchased 2007 Larson Lxi228 w/5.0 Volvo Penta Gxi and (not quite sure) out drive. I have an issue where the boat shifts into reverse and works fine at low rpm (to get off trailer, etc), but if you give it any more throttle it acts like you’ve spun a prop. You feel/hear a clunk and rpm’s go up with no movement. The boat works perfectly fine in forward. It just happened yesterday evening on our maiden voyage with this boat, and I haven’t cracked anything open yet to look. Just wanted to get some input on where to look and to and see if anyone else has experienced this and what are likely culprits. Thanks all! Have a great weekend.

 

[Horigan]

I would take the back over off the outdrive and confirm it is shifting fully into reverse when the control handle is moved to reverse. If it does fully move to reverse at the back of the drive, then you have an issue (worn cone clutch, etc) internal to the drive. If it isn't going fully into reverse, you may be able to adjust the cable, being very sure that neutral easily drops into the mechanism at neutral and forward clearly moves the rear shift mechanism into forward.

 

[Texasmark]

3 possibilities come to mind:
1. Disconnect the shifter cable at the engine/outdrive end with the control box at max R position.....don't let anything move when you make the disconnect that would affect shifting range. Grasp the lever where it was connected to the shift cable and see if it will move farther. If so, adjust your cable such that you have a slight overrun.....the cable can push slightly farther than the control can move.

2. Spring in the LU that operates the "Clutch Dog" that slides up and down the prop shaft is weak.

3. Clutch Dog R end and or it and the rear of the R gear are worn such that the sides are no longer vertical, but rounded off.

 

[Scott Danforth]

3 possibilities come to mind:
1. Disconnect the shifter cable at the engine/outdrive end with the control box at max R position.....don't let anything move when you make the disconnect that would affect shifting range. Grasp the lever where it was connected to the shift cable and see if it will move farther. If so, adjust your cable such that you have a slight overrun.....the cable can push slightly farther than the control can move.

2. Spring in the LU that operates the "Clutch Dog" that slides up and down the prop shaft is weak.

3. Clutch Dog R end and or it and the rear of the R gear are worn such that the sides are no longer vertical, but rounded off.

Volvo outdrives do not have dog clutches, they have cone clutches in the upper transmission

 

[Scott Danforth]

Hello all,
New member but long time boater. Recently purchased 2007 Larson Lxi228 w/5.0 Volvo Penta Gxi and (not quite sure) out drive. I have an issue where the boat shifts into reverse and works fine at low rpm (to get off trailer, etc), but if you give it any more throttle it acts like you’ve spun a prop. You feel/hear a clunk and rpm’s go up with no movement. The boat works perfectly fine in forward. It just happened yesterday evening on our maiden voyage with this boat, and I haven’t cracked anything open yet to look. Just wanted to get some input on where to look and to and see if anyone else has experienced this and what are likely culprits. Thanks all! Have a great weekend.

First, welcome aboard

Second, with any new to you boat, you need to do all the maintenance that the PO did not do

Third, a slipping cone clutch could be any of the following:

• Shift linkage at trans not adjusted right.
• Wrong gear lube used and you burnished the cone clutch
• Insufficient gear lube and you burnished the cone clutch
• Incorrect shimming of the cone clutch

 

[Texasmark]

Volvo outdrives do not have dog clutches, they have cone clutches in the upper transmission

I missed that. My Mercury experience is showing. Sorry.

 

[ShipShow]

Thank you all! I’ve got these are good areas to check, and will update this weekend when I tear into it.