Need some lower unit help here.

mdgpl73

Cadet
Joined
Sep 29, 2011
Messages
10
Hi guys, new to the forum but have been searching this site for the last few nights trying to find some info. Found some great articles but can seem to find what I'm really looking for. So, here it goes.

I recently bought a little boat. It is a 64 duracraft that has, from what I've read, a 1981 Chrysler 55hp with model number 559H1N. I bought this rig knowing that it did not go into forward. After some adjusting with the cables i got that to work. After last weekend at the river i figured I'd throw an impeller in it. I have done this many times on I/O's and inboards but never on an outboard. So i take out what i think is the drain plug and the vent plug. I disconnect the shift linkage that is in the middle with the pin and cotter pin. Bring the lower unit down and replace the impeller and gaskets. Go to put the unit up and the linkage for the shifter seems seriously loose. So I took it back down and took a look at it. After reading way to late on here last night i found out that i removed the pin that holds all the shift mechanism together. Stupid! Stupid! Stupid! I know.

Now I am trying to take the whole lower gear unit apart to put the shifter mechanism back together. So this is where I am at. I have the lower unit down to the point where I am up against a retainer ring. It does not look like a regular snap ring. It looks like just a plain metal ring. I have tried using a pick and other pick like tools to get it to pop out but have had no such luck. I am going to post some pictures and hopefully someone can shed some light on this and point me in the right direction. :confused:

This is the link of the parts diagram of the lower unit.

http://www.boats.net/parts/search/Merc2/Chrysler/55 (1981)/559H1N/GEAR HOUSING/parts.html

And if there is a thread somewhere that i did not seem to find, sorry. But i really searched for a long time.

IMG00643-20110929-1951.jpgIMG00644-20110929-1951.jpgIMG00645-20110929-1952.jpgIMG00647-20110929-1952.jpg
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Need some lower unit help here.

Take a long rod and hammer down once or twice on the aluminum bearing carrier. This should give enough play to loosen the rings. They are two 1/2 rings with a gap on each end. One end of each ring is beveled so you can ge a hook under it, but if you smack the carrier and turn the lower unit on its side, the ring should just drop out of the groove. Then flip the lower and do the other 1/2 ring.

NOW: When you go to reassemble the lower unit push the bearing carrier all the way down to allow clearance for the rings to fit in the groove. THEN once they are seated, use some 5/16 all-thread rod to pull up. Be absolutely certain that these two 1/2 rings are seated in the groove. When you put in the spool, they are squeezed between the bevel on the spool and the bearing carrier. They are the only thing holding in the gearpack and if they move out of the groove during assembly, when the engine is reversed, the whole gear pack, prop shaft, and prop will be lost.
 

mdgpl73

Cadet
Joined
Sep 29, 2011
Messages
10
Re: Need some lower unit help here.

Thanks Frank, worked like a champ. Got it apart for the night. I appreciate the help a lot!
 

mdgpl73

Cadet
Joined
Sep 29, 2011
Messages
10
Re: Need some lower unit help here.

I was able to get that out, plus the prop shaft. I took off the nut on the end of the drive shaft but cant seem to get the pinion gear off. I would assume that it would just slide off and is splined. I used a little force but doesnt seem to budge. Am I missing something here?!?
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Need some lower unit help here.

The pinion is on a locking taper at the bottom of the drive shaft. After removing the pinion nut, you must put a couple of aluminum or brass spacers in the lower unit, bearing against the bottom of the casting and the drive shaft threads. Wedge between them to drive the shaft out of the pinion. Some come easy, some will fight you.
 
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