Stuck in forward gear

[EastTexasBassFisherman]

I recently changed lower units on my 1994 Mercury 40 hp outboard. After putting the used one on I cannot get the motor to shift into reverse. Is there a simple fix to this problem? Thanks for your help.

 

[EastTexasBassFisherman]

Re: Stuck in forward gear

Sorry Fellas, I should have searched deeper. I found the answer I needed and was able to fix my problem in about an hour. Thanks anyway. I love this forum.

 

[Jacket4life]

Re: Stuck in forward gear

Where did you find the answer? And where you at in E. Tx??

 

[EastTexasBassFisherman]

Re: Stuck in forward gear

Jacket I am in Lufkin, TX. I can't find the thread for my first fix but it was an adjustment of the shift shaft. That got me unstuck from forward gear and able to shift into neutral and reverse. However when I shift into reverse it grinds and produces little thrust, not much more than at idle. I can hear an audible shift change from neutral to forward but it is not discernable from neutral to reverse.

 

[Jacket4life]

Re: Stuck in forward gear

I'm in Jefferson, not terribly far from you. It sounds like you may have a worn out cam.

You have good thrust in forward, I mean what seems like reasonably strong? If not, you could have a bad thrust hub. If so, then the cam isn't selecting it all the way to reverse, or the gear lash isn't adjusted properly, OR your reverse gear could be no good, but usually the symptom then is grinding, not poor thrust.

Wait a minute, lets eliminate the easy stuff first. Is this tiller or controller operated?

 

[EastTexasBassFisherman]

Re: Stuck in forward gear

It's on a 1994 Tracker super pro 16. Power tilt and trim. Console steering. A little history, I first bought this boat in 2002 and subsequently sold it in 2003. I recently got it back due to lack of use by the guy that had it. It had been sitting unused for several years. When I first put it back on the water I got a solid whistle alarm at high speed, bad impeller, replaced it. Then it started to stall out at high speed. I cleaned out the fuel lines/tanks and the carb. It kept doing it. I was told by a local mechanic in west Texas at the time that it was the lower unit going bad ($1400-$1800 fix) due to improper lube change/air in the gearcase. I bought a used lower unit from the same year model and size motor and installed it. It was stuck in forward gear. I adjusted the shift shaft and fixed that. Now I am at the not going into reverse part. From everything that I've read that sounds similar in symptom to mine it is the shift cable needing adjustment. I would like to try that first and see if it resolves the problem but I've never done that before.

 

[Hackamore]

Re: Stuck in forward gear

Before you go into a big deal with all this. Take the cowl off and adjuts your shift cable to push the gear farther back. If you are mechanically inclined you can see the shift lever and cable. Unhook the cable and push the shift lever as far back as it will go. then adjust the cable to fit the lever. All lower units don't adjust the same depending on a lot of things. Mostly controls. You can adjust until you get the forward and backward right. You can check the adjustment by turning the prob with your foot. In fowared it will turn way andn lock when you try to turn it the other way. In reverse it will do the same only it will lock the opposit way. If this does not work then check deeper as the other post said. Good luck.

 

[EastTexasBassFisherman]

Re: Stuck in forward gear

That will be my next course of action, thanks for the input.

 

[EastTexasBassFisherman]

Re: Stuck in forward gear

OK I adjusted the shift cable manually and with it in full reverse gear manually I can put my foot against the prop and make it stop and grind as it does under load. Could another adjustment of the shift shaft be in order or is it the reverse gear its self?

 

[Jacket4life]

Re: Stuck in forward gear

If it's all the way in gear and will GRIND, your reverse gear is probably shot.

I was hoping you were going to tell us it seems like it SLIPS in forward and reverse, that would have been your thrust hub...lot easier.

If you are going to try and rebuild the prop shaft assembly, you need to get a manual. I haven't done it yet, but I read through it in my Clymer book. The thing that worries me is you have to have a special tool, and you have to set the lash on the gears.

Oh, and what that mechanic described sounds a little fishy. Is he saying you ran the previous lower unit completely dry and mangled everything? That's the only way I can see $1400-$1800 for a fix.

 

[EastTexasBassFisherman]

Re: Stuck in forward gear

All he said was that there was air in the gearcase causing the gears to seize up. I may try to drain and refill the lube in the original gearcase and see how it does. How difficult would it be to take the reverse gear out of one unit and put it in another unit?

 

[Jacket4life]

Re: Stuck in forward gear

Look, you are putting lube into a sealed area. If you don't have enough, you have metal-to-metal, we all know (theoretically) that is BAD. "Air" in the area just means not enough lube. If you ran the lower unit DRY, you probably fried it. (IE, the gears are shredded/welded together/etc.) If you just ran it "low", then, theoretically, you may be able to lubricate it to standard and still be operational. Did you do damage? Probably. Is the unit "fried" probably not. You went out and got another unit, and it sounds like it had a whole different problem, IE, the reverse gear is screwed up, the shift shaft is screwed up, or it's not calibrated correctly. All I'm saying is that your original lower may not have ben completely trashed to start with. Obviously, if you want to continue on with the "new" lower, you have an issue.

As far as replacing one reverse gear with another, you need to get a manual and look at the process. I have not done it, but I am scared of it, because you have to do something called "setting lash" on the gear adjustment. I have read about it, but am not sure I could do it. That may be all that's wrong with your's now.

Doesn't mean you would not be able to do it, it just worries me because I haven't done it yet.