Mercruiser Shift Cable problem

bigdog · 03-14-2007, 07:45 PM

I have a 1995 4.3L Mercruiser, with a shift cable problem.
I noticed the problem started to occur, at the end of the boating season last Fall.

When I place the shift lever control in the neutral position, it wasn't necessarily "in neutral", as the boat continued to move forward.
This make me believe, that I need to adjust the "shift lever cable" ?
With a little "jiggling" of the shift lever, it seemed to go into "neutral".

Can someone describe how to perform adjustment of this cable ?
It would seem simple enough for DIY to perform without bringing to the dealer. Trying to save $$$ for other needed repairs.

Any help would be appreciated !

Dave R · 03-15-2007, 06:01 PM

You really need a manual for this work. The problem may be the cable, may be a problem with the drive, may be a misadjustment, or may be a problem with the shift interrupter switch. The interrupt switch actually interrupts the ignition for an instant when you shift. This relieves pressure on the gears and dogs and allows the drive to go in and out of gear.

Here's the factory service manual for the Gen 11 Alpha drive: http://www.boatfix.com/merc/Servmanl/14/14cover.pdf

Here's the Gen 1 manual:
http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf

Here's the 4.3 liter engine manual
http://www.boatfix.com/merc/Servmanl/18/18covr2.pdf

The tables of contents are hyperlinked to the chapter files online. Save them all if you want to have the whole manual.

Here's a link with a whole bunch o' Merc manuals and guides
http://www.boatfix.com/merc/mainmenu.pdf

Chris Craft · 03-15-2007, 07:57 PM

Like Dave said this is probably not a simple adjustment issue. It sounds to me like the interupt switch only because you said that if you wiggle it goes into nuetral. Of course I do not know if you are really talking wiggle or giggle

eye spy · 03-17-2007, 10:00 PM

Boat is 10 years old. Cable is about gone replace cable and shift boot.
Cable gets longer with more age and boot rots out also.
You may be able to adjust it but I don't think it will last. With spring coming up I would get it fix before summer

MJM · 03-18-2007, 11:05 AM

We had this issue also - and for us, it was indeed the iterruptor switch.

As always, very helpful posts from this forum!

Steve Di. · 03-24-2007, 01:58 PM

I have had a similar similar experience and found problems with shift interupters to be indicated by stalling when shifting and/or lots of force required to shift in and out of gear.

Cable problems have been evident by shifting into neutral and the boat remaining in gear; this is a dangerous situation that needs immediate attention. In my case, the problem was traced to the lower shift cable, not the main cable.

Good luck!

03-14-2007, 07:45 PM	#1
bigdog Senior Member Join Date: Apr 2006 Location: Central MA-Gilford Posts: 1,446 Thanks: 340 Thanked 119 Times in 96 Posts	Mercruiser Shift Cable problem I have a 1995 4.3L Mercruiser, with a shift cable problem. I noticed the problem started to occur, at the end of the boating season last Fall. When I place the shift lever control in the neutral position, it wasn't necessarily "in neutral", as the boat continued to move forward. This make me believe, that I need to adjust the "shift lever cable" ? With a little "jiggling" of the shift lever, it seemed to go into "neutral". Can someone describe how to perform adjustment of this cable ? It would seem simple enough for DIY to perform without bringing to the dealer. Trying to save $$$ for other needed repairs. Any help would be appreciated !

03-15-2007, 06:01 PM	#2
Dave R Senior Member Join Date: Jul 2004 Posts: 2,984 Thanks: 246 Thanked 743 Times in 443 Posts	You really need a manual for this work. The problem may be the cable, may be a problem with the drive, may be a misadjustment, or may be a problem with the shift interrupter switch. The interrupt switch actually interrupts the ignition for an instant when you shift. This relieves pressure on the gears and dogs and allows the drive to go in and out of gear. Here's the factory service manual for the Gen 11 Alpha drive: http://www.boatfix.com/merc/Servmanl/14/14cover.pdf Here's the Gen 1 manual: http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf Here's the 4.3 liter engine manual http://www.boatfix.com/merc/Servmanl/18/18covr2.pdf The tables of contents are hyperlinked to the chapter files online. Save them all if you want to have the whole manual. Here's a link with a whole bunch o' Merc manuals and guides http://www.boatfix.com/merc/mainmenu.pdf

03-15-2007, 07:57 PM	#3
Chris Craft Senior Member Join Date: Feb 2007 Posts: 120 Thanks: 0 Thanked 0 Times in 0 Posts	Like Dave said this is probably not a simple adjustment issue. It sounds to me like the interupt switch only because you said that if you wiggle it goes into nuetral. Of course I do not know if you are really talking wiggle or giggle

03-17-2007, 10:00 PM	#4
eye spy Junior Member Join Date: Dec 2006 Posts: 15 Thanks: 0 Thanked 0 Times in 0 Posts	Boat is 10 years old. Cable is about gone replace cable and shift boot. Cable gets longer with more age and boot rots out also. You may be able to adjust it but I don't think it will last. With spring coming up I would get it fix before summer

03-18-2007, 11:05 AM	#5
MJM Senior Member Join Date: Jul 2005 Posts: 262 Thanks: 0 Thanked 23 Times in 11 Posts	We had this issue also - and for us, it was indeed the iterruptor switch. As always, very helpful posts from this forum!

03-24-2007, 01:58 PM	#6
Steve Di. Senior Member Join Date: Jul 2002 Location: Wolfeboro, NH Posts: 60 Thanks: 8 Thanked 3 Times in 3 Posts	I have had a similar similar experience and found problems with shift interupters to be indicated by stalling when shifting and/or lots of force required to shift in and out of gear. Cable problems have been evident by shifting into neutral and the boat remaining in gear; this is a dangerous situation that needs immediate attention. In my case, the problem was traced to the lower shift cable, not the main cable. Good luck!