105HP lower unit damage

spool

Petty Officer 2nd Class
Joined
Oct 11, 2011
Messages
126
Hey,

I was at my local lake on the weekend, had a full day out having fun, the boat was running perfectly as usual, anyway loaded it back on the trailer and took it home. Only notice today that there was significant damage to the lower unit.

When I pulled it apart i noticed more and more damage followed by a heap of water in the lower unit along with no oil.

Previously its always held oil and never leaked. i'm guessing it i hit something and broke the seal and the gears munched them self. Either way I have a feeling I need a new lower unit.

Carnage pics.
http://i29.photobucket.com/albums/c295/paradox616/2013-03-18194854_zps31873157.jpg
http://i29.photobucket.com/albums/c295/paradox616/2013-03-18194958_zpse8b981f0.jpg
http://i29.photobucket.com/albums/c295/paradox616/2013-03-18195012_zps659042ce.jpg

what could cause this?
 

spool

Petty Officer 2nd Class
Joined
Oct 11, 2011
Messages
126
Re: 105HP lower unit damage

Hey,

I was at my local lake on the weekend, had a full day out having fun, the boat was running perfectly as usual, anyway loaded it back on the trailer and took it home. Only notice today that there was significant damage to the lower unit.

When I pulled it apart i noticed more and more damage followed by a heap of water in the lower unit along with no oil.

Previously its always held oil and never leaked. i'm guessing it i hit something and broke the seal and the gears munched them self. Either way I have a feeling I need a new lower unit.

Carnage pics.
http://i29.photobucket.com/albums/c295/paradox616/2013-03-18194854_zps31873157.jpg
http://i29.photobucket.com/albums/c295/paradox616/2013-03-18194958_zpse8b981f0.jpg
http://i29.photobucket.com/albums/c295/paradox616/2013-03-18195012_zps659042ce.jpg

what could cause this?

I found a 75HP outboard engine (complete) with a blown cylinder, does this use the same lowerunit as the 105?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Re: 105HP lower unit damage

What year? It will probably have a different gear ratio.
If it fit's you'll probably need to experiment with different props.
Maybe FrankA will add something here. He seems to know a lot about these older Chryslers??
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 105HP lower unit damage

The gear pack is totaled. Nothing salvageable there. Difficult to tell if the case is good but the bearing carrier at the rear is also no good.

The lower unit will fit only if it is PRE-1978 two piece. The one piece is completely different and will not bolt-up.. Drive shaft and splines, water pump, everything is the same. I am not sure about the gear ratio but even if it is different, you can change the prop pitch to compensate..

I think the only different ratio gears were on the three cylinder 90 and the four cylinder 135. so. both your lower units should be 1.73 to 1.

Since your lower unit is apart, simply count the teeth on the pinion and the drive gear. divide to get the ratio. On the one that is not apart, puit in gear and back up the prop until it is hard against the drive dogs. Mark its position. Now turn the drive shaft two rull turns and see what the prop does. If it turns only 1 turn I, gear ratio is 2-1 if it turns about 1 1/4, the ratio is 1.73 to i.
 

spool

Petty Officer 2nd Class
Joined
Oct 11, 2011
Messages
126
Re: 105HP lower unit damage

The gear pack is totaled. Nothing salvageable there. Difficult to tell if the case is good but the bearing carrier at the rear is also no good.

The lower unit will fit only if it is PRE-1978 two piece. The one piece is completely different and will not bolt-up.. Drive shaft and splines, water pump, everything is the same. I am not sure about the gear ratio but even if it is different, you can change the prop pitch to compensate..

I think the only different ratio gears were on the three cylinder 90 and the four cylinder 135. so. both your lower units should be 1.73 to 1.

Since your lower unit is apart, simply count the teeth on the pinion and the drive gear. divide to get the ratio. On the one that is not apart, puit in gear and back up the prop until it is hard against the drive dogs. Mark its position. Now turn the drive shaft two rull turns and see what the prop does. If it turns only 1 turn I, gear ratio is 2-1 if it turns about 1 1/4, the ratio is 1.73 to i.

Thanks Frank thats some good information!. My engine is a 1973 with a 2 piece lower unit, I'll need to find out what year the donor is first. Hopefully it's a straight swap. At least it happened at the end of the summer season down here.
 

spool

Petty Officer 2nd Class
Joined
Oct 11, 2011
Messages
126
Re: 105HP lower unit damage

So Frank, If its post 1978 (1 piece) can i bolt up the midleg & gearbox to my 105 or do the 3 cylinders use a different face where gearbox meets engine?

If i get this 75HP it will be the complete motor, just waiting on the guy to get back to me with the year/model.
 

spool

Petty Officer 2nd Class
Joined
Oct 11, 2011
Messages
126
Re: 105HP lower unit damage

i ended up getting a complete 125HP Force
 
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