Reverse shifting issue with stern drive of an OMC 1987 4.3L GM V6 (432APARY)

[becoleman3]

Shifts fine into forward but does not engage into reverse; I just hear the grinding of the gears. If I disconnect the shift cable I can manually move the shift arm and put it into forward and reverse with out any problems. Do you think this could be a problem with the shift assist module?

 

[southkogs]

I don't know the mechanical shift systems, but my first thought would be that the cable needs adjusting.

 

[bruceb58]

Sounds like an issue with your console shifter not giving you enough throw.

Just so you know, the only purpose of the ESA(what you are calling the shift module) is to stumble the engine when coming OUT of gear while you are in the water. It isn't needed going into gear or shifting out of gear when you are on muffs.

 

[becoleman3]

Thanks bruceb58 I will take a closer look at the throw, but the shifter does appear to be shifting equally in both directions.

 

[bruceb58]

When I say throw, I mean the throw back at the shift plate at the engine. You should be able to easily measure it.

If that's the case, you need to adjust the lower shift cable. You need the two OMC special tools to do it properly.

Failure to adjust this cable with the tools may result in you ruining the dog gears...a very expensive repair. Make sure you do it the correct way.

 

[becoleman3]

bruceb58, I have been testing this in the water while on my shorestation. In fact I wasn't having any shifting issues when out of the water under muffs. I put it in the water and ran it about a mile and when pulling it into the shorestation I shifted into reverse a couple of times with out any problems and then had an issue the third time and have not been able to get it back in since.

 

[bruceb58]

OK..if it was working ok and then started doing what you are saying, it's likely your lower shift cable has failed. Not unusual. I had a couple fail on me.

 

[becoleman3]

Thought so; but it's strange how I can manually do it from the shift arm.

 

[jim tubbe]

Had same problem on my 1980 hydro/mechanical lower unit. I finally gave up and installed a twin lever engine binnacle at the helm. I also cut out a slot on the bottom of the shift converter so it had a lot more "throw" on that delta shaped part where the two cables connect inside it. Just installed a 4 blade prop also, great for vibration reduction. Get rid of that stock multi tasked shifter, way to complicated when they get old.

 

[Speak]

Had same problem on my 1980 hydro/mechanical lower unit. I finally gave up and installed a twin lever engine binnacle at the helm. I also cut out a slot on the bottom of the shift converter so it had a lot more "throw" on that delta shaped part where the two cables connect inside it. Just installed a 4 blade prop also, great for vibration reduction. Get rid of that stock multi tasked shifter, way to complicated when they get old.

Not the same system as the cobra that Becoleman3 has. Totally different set up. Bottom line, buy the tools, check it or pay out the nose for new gears. If you dont have any history on that lower cable then replace it. Set it up properly and clean and lube the bell crank mechanism. If you do nothing you will grind those dogs to pieces. The repair costs are large even if you do the job yourself. Just my opinion for what is worth.

 

[Thajeffski]

The EXACT same thing happened to me last year.

The cause was corrosion down where the shift cable meets up with the shift rod thing down in the out drive. Ruined my lower clutch dog gears in the process... are you hearing a skip or thunking noise when you manually shift into either gear?

A new lower part of the drive, intermediate shift cable and hours and hours of work later. She shifts again and doesn't seem to have a problem.

 

[Lou C]

If you can shift it by hand with the transom shift cable without grinding but it grinds when shifting to rev with the remote control, you have to adjust the remote cable at the engine bellcrank (engine shift lever). Both the transom shift cable and the remote cable need to have equal throw in fwd&rev.