Change water pump, can't get lower unit back on

[Thoroughbred]

Have a 1997 Merc 150 Offshore. Changed the water pump and now can't get the lower unit back on. Reading what I can find says I probably made a big mistake by taking it off in Neutral.

I tried putting boat in Forward no go, tried in Reverse no go.

ANY AND ALL help you can give me would be appreciated especially since I leave for vacation in 5 days.

 

[Superjetjim]

Re: Change water pump, can't get lower unit back on

Right, I had the same problem last week, from what I recall you have 3 x things to line up in the following order:

1) The driver shaft splines - these can lined up by someone pushing the leg upwards while someone rocks the flywheel back and forth a little. That gets the first one...

2) The shifter - While again pushing the leg upwards ensure the male and female gear shift splines are aligned by moving the female end around to suit (this can be reached just above where it comes outside of the lower unit) once this is partially engaged proceed to step 3 below. Let me know if you need a picture of where this is.

3) Again while pushing upwards get some one to wiggle the shifter into gear FWD/Reverse only a tiny bit - this should allow it to close up the last bit by aligning these last splines.

Its a pain in the ar3e of a job lining it all up!

Good luck.

Jim

 

[Superjetjim]

Re: Change water pump, can't get lower unit back on

Here's the external shifter rod location for number '2' if you need it

HTH

Jim

 

[Thoroughbred]

Re: Change water pump, can't get lower unit back on

When you say "leg" are you calling the whole unit the leg?

 

[Superjetjim]

Re: Change water pump, can't get lower unit back on

When you say "leg" are you calling the whole unit the leg?

No, the section below the Doel Fin shown in the picture above

 

[Thoroughbred]

Re: Change water pump, can't get lower unit back on

No, the section below the Doel Fin shown in the picture above

Sorry that is what I meant the lower part of the unit that comes off in order to replace water pump. BTW I have the same Doel Fin.

 

[Superjetjim]

Re: Change water pump, can't get lower unit back on

Sorry that is what I meant the lower part of the unit that comes off in order to replace water pump. BTW I have the same Doel Fin.

Then yes thats the part I mean, video of it here if you've not already seen it?

http://www.youtube.com/watch?v=E-uzQi7IgwU

Cheers

Jim

 

[Thoroughbred]

Re: Change water pump, can't get lower unit back on

Thanks and yes I watched Jose before and again before doing it this morning but doesn't help with this issue. His advice to change thermostats is a great one. When I ordered the pump kit I ordered two stats and glad I did. Those things look like they are frozen. Bet they are the ones from the factory.

I ended up bringing the whole thing out over and over and turning the shaft (clockwise) about a 1/4" until I got lucky and it slid in.

THANK YOU FOR THE HELP!!!!!

Dave

 

[Superjetjim]

Re: Change water pump, can't get lower unit back on

Your welcome Dave. Glad it's sorted..

To test your thermostats take them out, boil a cup of water and lower them in and watch to see if the piston moves after a few seconds. Water needs to be freshly boiled.

Cheers,

Jim

 

[Thoroughbred]

Re: Change water pump, can't get lower unit back on

Your welcome Dave. Glad it's sorted..

To test your thermostats take them out, boil a cup of water and lower them in and watch to see if the piston moves after a few seconds. Water needs to be freshly boiled.

Cheers,

Jim

These looked so bad I just replaced them. Small price to pay for something that means so much to the motor and it takes 5 mins to replace both and they are cheap.

Now back to the original issue. Talked with a buddy last night after getting it on and he asked "how much of a pain was the shift rod? I said, "uh none at all" but then I started thinking about it. While putting the unit back on I was looking at water tube, bolts etc while holding the thing by myself and thought my daughter was getting the shift rod lined up but she later told me she was looking at the skinny hose (what is that BTW, looks like a vacuum hose) making sure it got though opening and didn't get kinked. She didn't look at shift rod.

I was so worried I went out in the dark and since you can't look straight down in there used a mirror and a flashlight. You guessed it shifting rod is NOT connected.

Sooooo I "get" to remove it again tonight. What a pain in the butt.

 

[Chris1956]

Re: Change water pump, can't get lower unit back on

Install the gearcase in Neutral. It is absolutely the best way, since the lower shift shaft is on a neutral detent and won't move on you. Don't forget the water tube guide tube, and to grease the splines of the shift and drve shafts.

 

[Superjetjim]

Re: Change water pump, can't get lower unit back on

These looked so bad I just replaced them. Small price to pay for something that means so much to the motor and it takes 5 mins to replace both and they are cheap.

Now back to the original issue. Talked with a buddy last night after getting it on and he asked "how much of a pain was the shift rod? I said, "uh none at all" but then I started thinking about it. While putting the unit back on I was looking at water tube, bolts etc while holding the thing by myself and thought my daughter was getting the shift rod lined up but she later told me she was looking at the skinny hose (what is that BTW, looks like a vacuum hose) making sure it got though opening and didn't get kinked. She didn't look at shift rod.

I was so worried I went out in the dark and since you can't look straight down in there used a mirror and a flashlight. You guessed it shifting rod is NOT connected.

Sooooo I "get" to remove it again tonight. What a pain in the butt.

LOL - yes the shift rod is a PITA!

They all line up one after another in order of length - first the drive shaft, then the pipe (which is the pressure pipe for your speedo if you use it) and then the shifter. The shifter is lined up by holding the rod where it comes out of the lower unit as I mentioned in point 2 above so they marry up.

Cheers - and have fun tonight *again*!

Jim

 

[nbnewbie]

Re: Change water pump, can't get lower unit back on

A couple of posts from the past. May or may not help.

For future lower unit stabbers, here is a little trick
I picked up from this forum and a little inginuity on my part.
When stabbing the lower unit I used a ratchet strap to
hold the lower unit up and also to slowly slip the
lower unit back in place.

I have used the strap method, and it does help but you might
consider this. I have since made myself 2 long studs out of
threaded rod, one for the front and one for the rear of the
lu. The rear one can either be threaded into the trim tab,
with a large washer and nut on top, or a large washer
and nut both above and below on the rear. Make them long
enough to easily start the threads into the lu. Then by
tightening one and then the other, you can easily bring the
lu up into place while lining everything up (shift linkage,
water pump guide tube). Once in place remove the threaded rods, and replace with proper front stud and rear bolt. Do be careful using this method, you can exert enough pressure to do damage if things are not lined up, but for me it works flawlessly and lu "stabbing" is no longer as frustrating as it used to be. Just a suggestion!

 

[Thoroughbred]

Re: Change water pump, can't get lower unit back on

Funny you say that because I used a strap once it went in. I had a couple in the back of my truck. Helped a lot to say the least.

Thanks for the long stud idea!


Also for everyone what grease do you use on the shaft gear? Wheel bearing grease ok?

I used Vaseline on the impeller, would that be heavy enough?

 

[Chris1956]

Re: Change water pump, can't get lower unit back on

Any good heavy grease is fine for the splines. I use a bit of oil on the impeller.

Gee, I never need a straps to reinstall the gearcase. Do you guys lock the motor up all the way, or install when verticle? Remember to wiggle the gearcase in place, using just your hands. If you use bolts and wrenches to install it, you will ruin the end of the crankshaft.

 

[ufm82]

Re: Change water pump, can't get lower unit back on

I've read here that greasing the impeller "may" not be good for pump operation as the grease interferes with the seal between the rubber and the housing. That being said, I always sprayed a little white grease on mine before installation and never seemed to have an issue. After my last go around with my overheat issue, I used dish soap this time as it will wash off the impeller once the water hits. You know what? It may be psychological but my pee stream is stronger now. LOL Maybe I'm imagining things but I swear it's stronger. No pressure gauge on my engine so I don't know for sure but I "feel" better!

UFM82

 

[Thoroughbred]

Re: Change water pump, can't get lower unit back on

Any good heavy grease is fine for the splines. I use a bit of oil on the impeller.

Gee, I never need a straps to reinstall the gearcase. Do you guys lock the motor up all the way, or install when verticle? Remember to wiggle the gearcase in place, using just your hands. If you use bolts and wrenches to install it, you will ruin the end of the crankshaft.

I locked all the way up and I just used the strap to hold it in place once I wiggled it in. Didn't want any risk of having it fall and I was in direct sun on a 95 degree day. That way I could take my time getting the nuts and bolts back on. I used vaseline after a OB mechanic on a you tube video said it was ok.

 

[Chris1956]

Re: Change water pump, can't get lower unit back on

OK, Normally I can get a bolt on the stud a few turns with fingers (no wrench), before the shift shaft is seated, so I don't need a strap.

 

[Thoroughbred]

Re: Change water pump, can't get lower unit back on

I could do that too Chris but with Murphy's law and the fact I wanted to take my time (first time on this size motor) and make sure it was snug the strap that I use to get hay for my horses came in handy. Kind of like having an extra hand.

Anyway got it working tonight. Dropped it only enough to get shifter rod in and it slide right back up with no strap btw but I did have my daughter helping.

My Merc is peeing again!!!!

THANKS for all the help!

 

[nbnewbie]

Re: Change water pump, can't get lower unit back on

Any good heavy grease is fine for the splines. I use a bit of oil on the impeller.

Gee, I never need a straps to reinstall the gearcase. Do you guys lock the motor up all the way, or install when verticle? Remember to wiggle the gearcase in place, using just your hands. If you use bolts and wrenches to install it, you will ruin the end of the crankshaft.

How have I ruined the end of my crankshaft? My outboard runs great!