65hp Mercury lower unit problems

[firefighter5406]

Hi guys! I have been fighting the lower unit to get it installed correctly. I've read everything on this site to help me line up FNR but I still can't get it. And I had lowered the lower unit so I could adjust the shift pin with pliers, like I'd been doing for the past two days, and I pulled up on the pin with the pliers about an inch and now the pin just spins. I don't know what I did? Did I pull it out of the socket is sits into? Or did I do more damage than that? Any nudge in the right direction would be much appreciated. Thanks, Doug

 

[emckelvy]

Re: 65hp Mercury lower unit problems

Doug, the good news is you won't have to disassemble the entire lower unit to fix your problem! You will however need to make or purchase a tool to get your shift shaft bushing out, so you can properly re-insert the shift shaft. That is, unless your 65 HP is real old and the bushing is surface-mounted where you can carefully grab the outside edges to unscrew it. Otherwise you can grind two "tangs" in a socket to fit the bushing.

What's happened is you pulled the shaft right out of the 'clip' that holds it in place. Since you haven't pulled the shift shaft all the way out, that clip is still on the shaft, just not in its retaining groove. So, when you get it apart, you can fix that.

As far as reinstalling the shift shaft goes, no sense in re-inventing the wheel, so take a look at this long-winded discussion we had this summer about that very same subject.

http://forums.iboats.com/showthread.php?t=264376

It should answer your questions, if not let us know.

HTH................ed

p.s. it might not be a bad idea to renew the bushing assy while it's apart. The part is not that expensive and comes with a brand-new & improved oil seal and a new O-ring.

 

[firefighter5406]

Re: 65hp Mercury lower unit problems

Thank you very much for the quick and thorough reply! I ordered one of those tools on ebay. And I read the info on the link you sent me and it made it very clear what I have to do. The only thing I don't know is you say there's a clip? But I don't remember it talking about how to clip it on? Or maybe it's self-explanatory once I pull it out. I'll work on it when I get the tool in. And I'll let you know how it went. Thanks again for your help. Doug

 

[emckelvy]

Re: 65hp Mercury lower unit problems

There are 2 styles of shift shaft retaining clip, one is just an "E-clip" type and the other one is more like what you'd call a "spring clip". In either case the clip goes in a groove cut into the shift shaft, just below the bushing assy.

Neither clip is real strong, and the groove isn't real deep, and that's why it's possible to pull the shift shaft out thru the bushing if a fair amount of force is applied.

If the clip isn't too distorted you could straighten & re-use it, otherwise run down to your local auto parts store and pick up an appropriate clip which fits the groove.

Probably better to replace it as it's likely weakened from its "ordeal".........ed

p.s. be sure to smooth out any "burrs" on the retaining ring groove before reassembly.

 

[firefighter5406]

Re: 65hp Mercury lower unit problems

Thank you for all of the useful info! I just got my tool in today, so I'm going to go try it. I'll let you know how I do.

 

[firefighter5406]

Re: 65hp Mercury lower unit problems

No luck. I spent a couple hours on it. I drained all the oil. I can look into the hole where the shift shaft should go, and I can see a hole almost to the bottom about the same size as the shift shaft. I turned the prop shaft until right before it clicks and look into it and I can just barely make out what appears to be maybe a rounded end of a rod facing to the front of the lower unit just below the hole. But I only see about 1/16 of a inch of it. No matter whether the prop is just before clicking or right after, I still see the same thing. I tried spraying carb cleaner, but don't see or hear anything rattling. And when I put the shift shaft back in, it still just spins. I'm stumped. Any help would be appreciated. Or if anyone knows where a cutaway view of this lower unit is so I can see what's going on down there. Thanks

 

[kingsnakejr]

Re: 65hp Mercury lower unit problems

Firefighter,
Go to crowleymarine.com and enter the year and model number of your motor and look under gear case or lower unit and it should give you an idea of what you're looking for.

 

[emckelvy]

Re: 65hp Mercury lower unit problems

Doug, the 'rod' you see is the shift plunger. The shift cam has moved forward in the gearcase, out of sight. If you carefully rap on the nose of the gearcase with a rubber mallet you may be able to jar the shift cam back into position.

You'll know when it's back because you'll see either the edge of the shift cam, the edge of the hole in the cam, or the "whole" hole, visible with a strong lite down the shift shaft cavity.

The cam has internal splines in it, so you'll be able to tell right away that's what it is. What you want is that splined hole to be perfectly lined up so you can get the shift shaft right back in it.

Note, be sure the propshaft is on the 'ramp', i.e. right before the 'click'. If you let it go past the 'click' you can't get the shift plunger to go 'aft' into the middle of the propshaft. And this won't allow the shift cam to move aft, either.

So, try positioning the prop shaft and give the front of the lower unit a few good whacks and see what happens. If you tilt the lower unit up a bit, it'll help the shift cam to move aft. It might be that there's still a bit of gear oil holding it in place, so I'd spray some more cleaner down there and swish it around.

HTH.........ed

 

[firefighter5406]

Re: 65hp Mercury lower unit problems

Thanks emckelvy! That worked! I found it and got the shift shaft mated back with the cam. It turns approximately 60 degrees or so like I read it should. But it only has fwd gear. Do I need to fill the lu with gear lube before it will shift? I'm stumped again. I really appreciate everyone's help through this. This site is a wonderful place for shadetrees' like me.

 

[firefighter5406]

Re: 65hp Mercury lower unit problems

Another quick question. Just to rule it out. Can the shift cam get shaken around and flip upside down in the gear case? I was wondering if that could happen and that that could be my problem why it's not shifting and is stuck in fwd.

 

[emckelvy]

Re: 65hp Mercury lower unit problems

Nope, the space is too small for the cam to flip. About all it can do is move to and fro without being held in position by the shift shaft.

There's a fair amount of effort needed to shift from forward to neutral, or from neutral to reverse; you'll need a set of pliers or something similar to grip the shaft. Try turning the prop or driveshaft as you shift and that might help.

 

[firefighter5406]

Re: 65hp Mercury lower unit problems

I tried with a pair of vise grips, but no luck. Is the gear a round one or oval shape? I thought maybe the gear wasn't aligned correctly and that's why it's not working. I'll try to put some lube in it after awhile and try it again. I'll let you know. I'm not gonna give up. The motor runs way to good to do that! Plus, I just had to put a new rotor with shaft in it. And they're not cheap! Thanks everyone for all your help.

 

[firefighter5406]

Re: 65hp Mercury lower unit problems

I found out, after paying to have the lower unit fixed, that there are two castings inside the lower unit that the shift cam rests between. Well, I somehow broke the bottom casting that the shift cam sits on. So that is why it wouldn't shift anymore. I guess I'll look for a case now. Thanks everyone for all of your help. It's much appreciated. Thanks, Doug