- This topic has 2 replies, 3 voices, and was last updated 3 years, 9 months ago by
.
-
UPDATE: This may now be working, I need to barrel test, but putting the lower in neutral seems to have gotten me back on track. I’ll update this one I’ve tested.
Ok, so 5 hours ago my journey began of replacing the impeller on my 62 Merc 700. Yes, it takes me 15 minutes on my old 25HP Evinrude :).
Anyway, here is where I am now. I was having problems getting the lower to seat back into the upper, just about 1/4 inch. When I took the lower off I had it in forward, and I have found that the only way to get the lower to seat properly is to put the shifter in reverse. That doesn’t make sense to me.
Currently the transmission is in forward (turning prop clockwise clicks, counterclockwise turns the shaft).
So I thought that maybe I had bumped the shifter in the lower so I turned the shifter all sorts of ways and could never get it in reverse, it just won’t hit reverse. I can get it in neutral if I turn the shifter counterclockwise until it “pops” into neutral, then the prop spins freely.
I know there is a pin that is supposed to be a safety device, where if the pin isn’t engaged then it’s not supposed to do something – I think it’s to not go into reverse. Is that the problem?
I don’t know if I messed up the proper alignment of things. In the picture you can see the shifter and a collar for it, and I’m not sure the proper orientation of the shifter now. It turns 360 degrees (stops a bit after that), so I can turn it fully either way and the collar “sinks in” (see pics). Neutral is way to the left, so I’m assuming that I need to rotate the shifter to be closest to neutral, however I still can only get the lower mounted if the front shift lever is in reverse – even though the engine is NOT in reverse.
It has been very frustrating, to say the least. I’m now down to “I have no clue after five hours” and forced to take it to a mechanic and pay hundreds of dollars for what should be a simple impeller replacement. Any help is greatly appreciated.
The Merc shift shaft has six splines and can go any one of six different ways. Mercury has always stated in their manuals that the lower units should be removed and installed with the lower unit in forward. I have found over the years that this is pretty much baloney and neutral is really the way to do it, if you are gentle. What the problem is, is that the Merc sliding clutch is spring loaded in forward. This is great, because when have you ever seen a worn forward gear and clutch on a Merc? ( I didn’t say, “rusted;” I said worn!) The mechanism that moves the clutch is a cam, that the the vertical shift shaft twists back and forth. If you remove the gear case in neutral, there is the chance it can be bumped off the cam’s neutral position and the shift will slip into forward. If the mid section is still in neutral, this could end up being a problem; so they say to do it in forward. The trouble is, in forward, the shift cam detent is not well defined and can go too far past the forward direction, making it very hard to line the splines back up. Some people get the lower shaft position so far out of whack that lower unit will actually shift backwards, because the cam is now working off its back side. Anyway, if you remove and install the the lower unit in neutral and be careful not to jar it too much, the splines will go back together pretty easy, because the unit will stay almost perfectly in neutral, due to the nice, defined step on the cam. Just be sure to check the shift operation before going boating. In forward, the prop should lock one way and ratchet in the direction that the prop would normally drive the boat forward, in the other.
The clutch-dog-looking thing on the shift rod is part of the reverse lock mechanism. That is a whole other story. The way it is supposed to work, you may ONLY lower and raise the motor in FORWARD gear, engine off. That’s right; you shut off the engine, THEN push it into forward gear and tilt the engine up. Conversely, you lower the engine in forward gear and then shift to neutral and start up. Despite what it looks like, that ramped piece on the lower shift shaft is not really supposed to lift the reverse lock into neutral.
Always remember Mercury’s long standing (to this day) engineering motto: Look around, see how everybody else does it, then do the opposite.
Long live American manufacturing!
- You must be logged in to reply to this topic.
