1989 Force 85hp lower unit housing cracked

[iref]

'89 Force outboard 85 hp model # 856A9F.
I'm afraid I know the answer to this, but here goes....
While getting my boat ready for Memorial day weekend, I noticed a 2 inch long horizontal crack in the cast aluminum prop shaft housing, about 1/2 way between the front nose and the prop shaft coming out the back. A small rust stain can be seen coming from the crack. I'm thinking this means there was water ( Lake Erie ) in the lower unit oil, and it froze this winter in outside storage. Before noticing this crack I tried to start it up and it cranked OK for several seconds but now it will not crank and I can't turn the prop by hand. The genius' I work with instantly suggested JB weld for the crack but that won't solve what is probably some kind of damage to the gears or bearings. Does anyone have any past experience with this kind of problem? I'd be grateful for any comments/advice.

 

[bman1bpm]

Re: 1989 Force 85hp lower unit housing cracked

sounds like you better start looking for a new lower unit to me.

 

[Frank Acampora]

Re: 1989 Force 85hp lower unit housing cracked

Rust leaking out and a stiff prop are pretty much the kiss of death.

Start looking on ebay. Any lower unit from any Chrysler or Force 3 or 4 cylinder --EXCEPT the Force 70, also except a 25 inch shaft length (a few were made)--from 1980 to 1989.

Next year, change the lower unit oil BEFORE storing the boat.

 

[bman1bpm]

Re: 1989 Force 85hp lower unit housing cracked

theres one on ebay right now for $199 says its a working pull I think from an 85 horse. There is also one that was just rebuilt for $499. I think I searched chrysler lower unit.

 

[jerryjerry05]

Re: 1989 Force 85hp lower unit housing cracked

On e-bay you need to cover all the topics.
Force Force/Mercury Force outboard Chrysler and any combo you can think of. Jerry

 

[iref]

Re: 1989 Force 85hp lower unit housing cracked

Thank you all for your responses. As a first-time boat owner i sure have learned an expensive lesson. A little time invested in replacing the lower unit lube would have saved me alot of grief. I'm going to check out the Ebay listings right now.

 

[iref]

Re: 1989 Force 85hp lower unit housing cracked

http://cgi.ebay.com/ebaymotors/MERC...010QQitemZ200224010100QQrdZ1QQsspagenameZWDVW

The only question i have about this one is the 2:1 gear ratio designated by the stamped letter 3. Mine doesn't have that. Will it still work for me?

 

[Frank Acampora]

Re: 1989 Force 85hp lower unit housing cracked

They only made 2 lower unit gear ratios: 2 to 1, and 1.78 to 1. 85s came with either gears -- I guess depending upon the whim of the factory. If your engine had the 1.78 to 1, then the 2 to 1 will really perk it up. You need to go up 2 pitches on the prop but you will most likely see 4-5 MPH more at wide open throttle.

So, yes, it will work and if you have a tach you will know right away if you need to go up in pitch--RPM will be 400 or so higher than with the original. However, a lot of the 85s also came original with the 2 to 1 lower gears. Yours may be one of those. If so, nothing needs to be done.

If I can find them, I only use 2 to 1 gears on all my Chrysler and Force 3 and 4 cylinder engines

 

[iref]

Re: 1989 Force 85hp lower unit housing cracked

Frank, I got my lower unit off today, mine has the 2 piece shaft. Will the 1 piece shaft like on the one I was looking at on Ebay in my previous post interchange?
Incidentally, the bearing under the water pump housing appears that it hasn't seen lube in a while, reinforcing my newly found belief in always knowing how much clean lube is in the lower unit.

 

[Frank Acampora]

Re: 1989 Force 85hp lower unit housing cracked

HMMMM----- INTERESTING----

Are you sure that your existing lower unit is an '89? Or that your engine is an '89? I always thought they used a one piece drive shaft through 1989 and switched to a 2 piece in in 1990. Maybe you have a late '89 year production engine incorporating the 2 piece shaft.

At any rate, not to worry. I have a 1990 90 with an earlier 1 piece drive shaft bolted to it. Drive shaft length is the same and although they changed the water pump, the outlet is in the same spot. Shift rod is the same too. As long as your engine doesn't have the MERCURY lower unit and midleg, you should be OK.

 

[iref]

Re: 1989 Force 85hp lower unit housing cracked

I can't be sure that the lower unit is the original. I'm not the original owner and there's no telling what has happened over the years. The small sticker on the motor shows that it's model # 856A9F, I believe the ''9'' designates the 1989 year. My Clymer manual has an illustration of the 2 piece unit and mine looks just like it. The book goes on the describe several different arrangements for the lower unit and drive shaft. The photos of the units I'm considering on Ebay show the water tube in the same location. As long as the OAL of the shaft is the same I see no issues so far.