1970 Mercury 800 shift shaft stuck after water pump replacement

[SunnyJimWhite]

CORRECTION: originally this post was titled saying Mercury 800 is from 1978. It's NOT 1978 but a 1970 (this disclaimer was added later...)

Hello all, and thanks in advance for any advice. First of all, it's a new boat to me, ran well but not much water pissing out, so I decided to change the impeller. The motor also wouldn't go into reverse, though it did grind just a little as if it was trying to.

I've read a few other threads regarding this question: after replacing impeller and putting the lower unit back on the motor, the prop spins only clockwise (and I hear the pawls clanking)in all three gear settings (from the drivers seat control). In the other threads, people refer to the "lower shift rod attaching or mating to the upper shift rod". My motor seems to only have ONE long shift rod that comes out the bottom of the power head. It inserts into a small hole with an oil seal just in front of the water pump assembly. I put the control unit in forward (like the Seloc manual I have for this motor says to do) before dropping the lower unit. I didn't remove the prop in the whole process (manual says to) and it did get moved around (thus turning the gear box) both clockwise and counter clockwise. Big mistake?

Any help here?

Thanks!

 

[carholme]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Do you have the LU removed, If not, remove it and using finger pressure only on the prop, tell us what gear the LU is in?

Forward: Prop will turn (ratchet) CW but not CCW
Neutral: Prop will turn freely in either direction
Reverse: Prop will not turn in either direction except for the amount of gear mesh.

What is your engine s/n?

Your long shift shaft connects to the lower shift shaft which is the one in the LU. I will send you the parts list when you give us the s/n.

Gerry

 

[SunnyJimWhite]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Do you have the LU removed, If not, remove it and using finger pressure only on the prop, tell us what gear the LU is in?

Forward: Prop will turn (ratchet) CW but not CCW
Neutral: Prop will turn freely in either direction
Reverse: Prop will not turn in either direction except for the amount of gear mesh.

What is your engine s/n?

Your long shift shaft connects to the lower shift shaft which is the one in the LU. I will send you the parts list when you give us the s/n.

Gerry

Hi Gerry-

I did more research after posting, and it seems that my shift shaft has stuck to the motor, and has pulled out of the LU.

The serial number of my motor is 2885431

The prop will rachet to the left, meaning I'm stuck in fwd. I had used the boat for a couple hours, and of course noticed that it wouldn't go into reverse. I think I inherited the messed up shift shaft when I bought the boat.

How do I go about removing (to replace) the upper shaft? Do I remove the lower cowl? I have some photos of what's going on and will try to post them shortly. Thanks again for any advice or help you can offer.

James

 

[carholme]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Just to confirm, is this a four or six cylinder?

Gerry

 

[emckelvy]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

You don't have to remove the powerhead or the upper shift rod to get the shift shaft unstuck from the upper shift rod.

Just heat up the shift shaft area where the aluminum coupler sits and you should be able to pull the shaft out. You can grab the shift shaft in the middle with some Vise Grips, cushion with a shop rag so it doesn't tear up the shaft. Any burrs in the shaft from the Vise Grips would have to be smoothed out with a file then sandpaper.

This recent thread describes this problem, with pictures and good advice on getting things apart:

http://forums.iboats.com/mercury-mariner-outboards/war-lower-unit-590009.html

Now, you have another problem, trying to get the shift shaft installed back in the lower unit. You'll need the special tool to remove the shift shaft bushing assy, or grind a couple of tabs in a socket, to engage the slots in the bushing. Once the bushing is out, you'll have to do some very specific things to be able to get the shift cam in a position where you can reinsert the shift shaft. Note that there's supposed to be a retaining clip in the slotted area of the shift shaft, so be sure you've installed a new clip.

Here's a thread which describes how to get the shift shaft reinstalled without having to disassemble the lower unit:

http://forums.iboats.com/mercury-ma...lling-shift-shaft-into-lower-unit-264376.html

Here's a shift shaft bushing tool for sale here at iBoats, not a bad deal for $18: Shift Shaft Bushing Tool - Sierra 18-9817 - iboats

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

 

[SunnyJimWhite]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Just to confirm, is this a four or six cylinder?

Gerry

Four cylinder. And looks like it was pretty much run in fresh water its whole life. I did replace the wiring harness and switch box, as it wouldn't start at first. After that, it ran like a charm except that it wasn't pissing much water and it wouldn't go into reverse. That made for an interesting trip into my boat basin and slip. Slow and steady.

 

[SunnyJimWhite]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Ed-

The first thread was a great read. And it appears to be nearly exactly what my situation is. I'll try to heat it up and tug on it. I did do the vise grips and tap that with a hammer thing already, but didn't have time to heat it up. The retaining clip is gone, and I may make the shift shaft bushing removal tool from a socket, as I'm about to leave home for three weeks and would love to have this project wrapped up so I can sleep while I'm gone.lol

Thanks for all the help, I'll let you know how it all turns out. This forum has been fantastic.

James

 

[carholme]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Well that s/n clears up as bit of confusion as it comes up as a 1970, not 1978:

80 1970 S&L 2783253 - 2986443 2786463

From here:

MERCURY OUTBOARD MODEL YEAR GUIDE 60 HP - 100 HP -- Mastertech Marine

Parts list for model 1800100:

MERC 800E - Mercury, Mercruiser, Force, etc. Parts Lookup

Here is a link to the condensed version of the Clymer service manual. Download it soonest to your computer as the link is short lived.

Small Engine Repair Reference Center Home: MERCURY - MERCURY FOUR-CYLINDER MODELS (1969-1989).

In this link from the parts manual, scroll down to item 48 and click on the picture of the cam and click on it again to blow it up. Is this the type of shift cam you have or is yours the two piece metal shift cam?

Mercury, Mercruiser, Force, etc. - GEAR HOUSING ASSEMBLY, COMPLETE - MERC 800E

Gerry

 

[SunnyJimWhite]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Gerry-

I don't know why I typed 78... sorry for the confusion. I have the one piece shift cam, it looks like. And it looks like plastic to me. It is very black. I guess it could be oil stained? And the link to the Clymer service manual would not go through for me. I'm about to go out an apply heat to the shift shaft and try to pull it out. I'll let you know how that goes.

James

 

[SunnyJimWhite]

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

Re: 1978 Mercury 800 gear stuck after water pump replacement Help!

I heated up the shaft and it pulled out with a couple of whacks. I had trouble with my Ace Hardware torch, it kept cutting out, and when I turned from dealing with that, I saw that the shift cam was slowly burning on the bottom, bubbling up. So it's definitely plastic. I am about to get the shaft splines cleaned up and see if it's going to work. Again, thanks for all the help. I will post the outcome.

James

 

[carholme]

Re: 1970 Mercury 800 shift shaft stuck after water pump replacement

James;
Will try this again in the hopes that you are back on here soon.

Small Engine Repair Reference Center Home: MERCURY - MERCURY FOUR-CYLINDER MODELS (1969-1989).

Gerry

 

[SunnyJimWhite]

Re: 1970 Mercury 800 shift shaft stuck after water pump replacement

Gerry-
I was able to download the file. Thanks. I'm sure that will come in handy.

I cleaned up the parts and put them back together to test everything. The lower shift shaft is not engaging with the ramp in the bottom of the gear case. I guess it's time to pull out the shaft seal and have a look down in there. I believe that was covered in one of the other threads. My problem is of course, time. I'm leaving town tomorrow for about a three week road trip. I may just take the lower unit to a shop and let them have at it. I haven't decided yet.

 

[emckelvy]

Re: 1970 Mercury 800 shift shaft stuck after water pump replacement

Yeah, there's just about no way to get the shaft reinserted properly unless you remove the shift shaft bushing/seal assy.

Since you're leaving for 3 weeks, maybe this is a good time to order one of those shift shaft bushing tools, it'll be there when you return!

Have a good trip..........ed

 

[SunnyJimWhite]

Re: 1970 Mercury 800 shift shaft stuck after water pump replacement

Just a quick update: it's all back together after I took the lower unit to a local repair guy to fix while I was away. When I first put it together, I had an issue with reverse lock not letting go in any gears, even though I had forward and revers and neutral. I had to remove the LU and reposition the shift cam so the reverse lock was not "on" (controller in fwd as well as gears). All working like a champ now, and impeller making a great stream. Thanks for the encouragement and the enthusiasm on this forum. This was my first time working on an outboard, and I got through a lot of it with your help. Have a fun and safe 4th of July 2013..