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Shift Cable adjustment question

Chris Rohde

Chris Rohde

Regular Contributor
I think I need to adjust my shift cable. Here's what's going on;

When going from forward to neutral, drive goes into neutral just fine.
When going from reverse into neutral, boat stays very slightly in reverse, like it's barely engaged, but still engaged.

I looked at this for a moment on land at the end of the season, and had the wife put the boat in forward and reverse, while I looked at the drive with the cover off. It appears that the linkages move the lever to the proper position, but again, it does stay very slightly reverse. I remember making a slight cable adjustment at that end, but it didn't fix anything the next time we went out.

Just wondering if this is common, and if there is anything I should look for that might jump out as an obvious problem. I plan on taking a look again this weekend, and any tips would be greatly appreciated!!

Thanks!
 
A number of things could cause this. Lets look @ the cheap fixes first.. Firstly I'm assuming that when you say it stays slightly in reverse that you mean that the shift "rocker" (under the cover towards the top) is not moving fully into its detented position?????

1) make sure the clamp plate ( an open U on one end and a hole for a hex bolt on the other) that secures the cable jacket to the drive housing is properly installed and tight.

2)The standard setup for the fitting on the end of the shift cable is a single washer and a cotter pin. Sometimes a second (thin) washer needs to be stacked on the pin where it goes into the arm to remove slop. I have one washer between the cotter pin and the arm and another one on the other side of the arm towards to cable end fitting.

3) Make sure there is no excessive slop @ the helm shifter arm on the back of the control also.

4) No excessive slop at any of the junctures at the drive end between the cable end and the "rocker"

Remember, when properly set up the cable end from the shift cable is expended out for FWD.
 
Disconnect the link going to the eccentric piston on the upper gearbox and see how well it shifts by hand with the engine running. What is the engine idle rpms in neutral? It could be slop in the control bushings also see how far you can move the control handle before the shift cable moves. When I put new bearings in my upper gearbox the eccentric piston had a little burr that kept it from snapping into neutral detent position. If it sticks when you shift it by hand pull the shift eccentric piston clean it up get a new seal and o-ring and replace what is necessary.
 
Chris, take heed of what Bob and Kim are suggesting. Give their suggestions a try!

I always begin at the shift unit by starting in absolute Neutral, and then adjust all else to accommodate.





Regardless of the year/model, your Volvo Penta drive uses "cone clutch" gear engagement.

Within the transmission (upper gear unit) there is one main "drive" gear, and two "driven" gears each with sliding sleeve "cups" on them.

There is also a sliding sleeve that fits onto/over the steep spiral cut splnes of the vertical shaft.

All three gears rotate when the engine is operating..... therefor both gear cups are rotating.

As the sliding sleeve is either raised or lowered (via the eccentric piston/shift shoe), it begins to engage with a gear cup.

As it begins to engage, the steep spiral cut splines create friction between the sleeve and corrisponding gear cup.

As friction increases, lock-up eventually occurs.


Sometimes metallic contamination causes the sliding sleeve to remain locked within a gear cup..... or at least has become sticky, so to speak!

The shift shoe groove is eccentrically cut into the sleeve as to create a mild "hammering" affect when gear disengagement is attempted. You may not feel this at the shift lever, but it is occuring!


As suggested, drain the gear oil and pull the shift mechanism out and examine the eccentric piston and shift shoe.
It will cost you 3 new O-rings only!

If all is OK, then it is most likely metalic debris in the sliding sleeve oiling grooves and/or on the cup itself.
Unfortunately, this fix would require transmission disassembly.



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