Mercury 500 reverse lockout rod install, frustrated as all heck!

I have a '77 Merc Thunderbolt 500, I installed a new lower unit last year only to find out that the reverse lockout rod was missing. This is a long shaft engine with that little 5" or so extender between the shaft housing and the lower unit, s/n #4803973.

I purchased a new-old stock reverse rod and I tried to install it today. Up inside the driveshaft housing, there is little plastic winged piece that is a guide for the shifter shaft and the reverse lockout rod. When I install it, the shafts are parallel and seperated by maybe 1/8" at the most. When I try to install the mid spacer section, there is a round hole where the shifter shaft and the reverse lockout rod go down thru. There doesn't appear to be enough room to get that shaft and the lockout rod down thru there without them binding and being forced together. If I remove the plastic guide from up above, I can get it ON, but it still seems too tight.

The mid section and the plastic guide are original to the engine. The mid section has 2 pins that prevent me from being stupid and installing the piece upside down. Without the reverse lockout rod, I had the lower unit on last year and the motor running with no problem. The odd part is that if I lay the winged plastic on top of the mid section where it would normally sit right above, it is obvious by the holes that it would never fit right. It almost looks like the mid section should have a notch in it to allow room for the reverse lockout shaft.

This is the last thing that I have to do to this boat to get it wet, I completely gutted it last year and rebuilt it. Needless to say, it never got wet last year and thsi issue has frustrated me to no end. I'll bet that I spent 4 hours in the on/off rain today with no headway! BTW, I have a manual on CD, its about useless on this issue.

You need to install with Lowe unit off

Yes, the lower unit is off. I fished the rod up thru and installed the clevis and pin on top. Currently the rod is adjusted to the same length as the shifter shaft, I can freely push the rod up and down as it activsates the clamps up top. The shift shaft and the lockout shaft are parallel to each other sticking down where the lower unit will push up. The issue is when I try to install the intermediate driveshaft section, the hole in the intermediate piece is not large enough for the shift shaft and the lockout shaft to penetrate unobstructed.

Update; Here are pictures of the parts and pieces.

plastic spacer: http://i154.photobucket.com/albums/s276/hotrod53/Boat%20Album/Wingedspacer.jpg

Here is the intermediate piece between the upper and lower unit: http://i154.photobucket.com/albums/s276/hotrod53/Boat Album/Intermediatepiece2.jpg

Intermediate lower driveshaft cover, notice the round hole on top, the spacer goes in the upper section just above this but could slide down to this hole: http://i154.photobucket.com/albums/s276/hotrod53/Boat Album/Intermediatepiece.jpg

alignment of shifter shaft and reverse lockout with guide in place: http://i154.photobucket.com/albums/s276/hotrod53/Boat Album/Shaftspacing.jpg

Supposed installation of the guide, this could be upside down but it makes no difference to the issue: http://i154.photobucket.com/albums/s276/hotrod53/Boat Album/Spacerinplace.jpg

Here is the problem, notice how the reverse rod hole falls over the edge: http://i154.photobucket.com/albums/s276/hotrod53/Boat Album/Spacermisfit.jpg

Try installing the plastic guide in the leg above the extension spacer where it would go without the spacer,the shifter and the rev lock rod will still fit through the hole in the spacer

Yes, that is where I am installing it. I realize that its hard to visualize and for me to properly explain it, but the picture that I show holding the guide over the shafts is me sticking it up into the upper section without the mid section attached. The hole in the upper piece is shaped like the spacer and it fits up in without an problem. The problem is that when the shift shaft and the reverse lockout shaft are spaced parallel by the guide shoved up in the top piece, the two shafts together will not fit easily thru the round hole in the mid section. If I do get it down thru, it is so bound that it will never work correctly.

Let me try explaining it this way.... The shifter shaft goes directly in the center of the mid section round hole, the spacer holds the shifter centered and lockout shaft parallel to it. The lockout shaft must fit between the center line of the hole, which is occupied by the shift shaft, and the outer edge of the round hole. Picture a triangle with a round shaft in the middle, the distance between the round shaft and the point of the triangle is the only area where the second shaft can fit. There is no notch in the mid section for that to fit, therefore it appears to want to bind or not fit at all.

I get you now,time to get out the reamer and redesign that round hole in the spacer/extension.It's the only way I can see around it

I'm tending to agree with you, but I'd sure like to know how it worked all these years as it is???

I called a local marine repair service and he seemed to know exactlyu what I was dealing with. I'm hauling it over there tomorror for him to look at it.

Hotrod,has this engine got PTT by any chance? If it has you don't need the reverse lock rod as the PTT doesn't allow the outboard to rise up in reverse

It does not have PTT, all manual

Oh well another thought blown out of the water My only other thought is that the previous owner had the same problem and that is why they removed the reverse lock rod.The reamer seems to be the last resort

UPDATE: I took it to a marine repair facility... He tells me that this motor is a short shaft motor with a Bay Manufacturing shaft extender kit on it. There is an extension piece for the driveshaft, the shifter shaft, and probably at one time, one for the reverse lockout. The midsection is a part of the kit, therefore it never showed on my breakdowns.

I have Emailed Bay Manufacturing to see what they suggest. Our options seem to be 1. modify the OEM long shaft rod somehow 2. notch the extender piece, 3. buy a short shaft lockout and a new shaft extender form Bay Manufacturing.

I think by the time I am finished here, I could have purchased a used motor. I hope its worth it in the long run???

Notch the extension piece,cheapest option,and IMO,for what it's worth,the easiest. Ten minutes in a machine shop,or twenty in your own shed.Idle curiosity,that extension piece makes its a long shaft/20"? Bound to be long shaft mid sections on Ebay.But that means you must remove the power head.Ream it,cheapest option

Not sure what the total length is now, have to wait till I get it back to measure it. Suprisingly the driveshaft extender stayed up inside of the power head. I drove that thing 50 miles on the trailer and it didn't fall out! That may be the first good thing that happened to this boat all month....LOL!

Measure the drive shaft,I bet it's roughly 21+" long,'cause I don't think there is a shaft extension piece.I may be wrong, wouldn't be the first time,refer to user name. But if you are fed up with it,put it in a box and I'll take care of it for you

The guy at the Marina shined a flashlight up inside the power head and said he can see the extension piece, I personally didn't see it. From what I understand, extension pieces for the driveshaft and shifter are common parts of the kit. It's in his hands now... what the heck, it's only money...LOL. I'm puttin' this thing in the water this year damn it! LOL I'm tired of looking at all those new seats and new carpet, I want to splash some fish guts on it all!

I goggeled it and sure enough the it is.I live and learn

This story just keeps getting better! I received a call from Bay Manufacturing today, and kudos to them, their tech support was fantastic! As it turns out, the reverse lock actuator, that plastic splined piece with the steps in it, is supposed to get removed and installed up above the space piece in that round hole! Apparently it slips over the splines of the extension piece for the shift shaft. This allows the stock reverse lock rod to work as intended, unfortunately I purchased a new long shaft rod when I should have purchased a short shaft rod. We're hoping that we can move the actuator piece and cut off the reverse rod.