1989 force 85hp 2 piece shaft

[bigfish90]

I have a 1989 force 85 hp that has a 2 piece shaft lower unit, it measures 20.5 inches from the top of the pump housing. I have to replace the lower unit. Can I use a lower unit with a one piece shaft as the 2 piece is hard to find.

Thanks
John

 

[Frank Acampora]

Re: 1989 force 85hp 2 piece shaft

The long shaft is 18.5 inches not including the locating "***" on the end, or the coupler. The extra long shaft is 23.5, again, not including the coupler. SO If your measurment included the coupler and the stub from the pump, then you have a long shaft engine and you would buy a lower unit with a one piece drive shaft from a 20 inch engine.

The one piece lower unit came in two different gear ratios so depending upon what ratio is in yours now, you may need to change prop pitch

 

[jerryjerry05]

Re: 1989 force 85hp 2 piece shaft

Not sur ethe older 1 piece will fit???
Will take some measurements in the am and post with pics.

According to the parts cross over it won't work???

 

[Frank Acampora]

Re: 1989 force 85hp 2 piece shaft



Here is an old Chrysler 105 with a 2 piece drive shaft and a one piece. I use it to test lower units that I have repaired and are for sale.

Not to worry, Jerry. I switch one piece and two piece lower units on my Chrysler and Force engines regularly. They all will swap, up until the lower was changed to Mercury. On a very few midlegs you would need to grind clearance in two of the mounting bolt lugs to clear the water pump.

And, if you get a little creative, many different props can be used.

 

[swiggins]

Re: 1989 force 85hp 2 piece shaft

I have the 89' 85 hp force with the 2 piece shaft. I have a spare 89' 85hp force with the one piece. The one piece didn't fit, it was about an inch longer so I couldn't bolt the lower unit on.