RESOLVED: "1984-94 25-50HP" : Which Lower Units are Compatible with 40/50HP 1994?
After another couple of hours reviewing Force forum posts, I found a reply to my question. For my 1994 Force 40HP motor, compatible lower units are found in 1984-1994 25HP to 50HP motors. Master roscoe found the information in his "manual". Thank you Master roscoe.
http://forums.iboats.com/showthread.php?t=151572&highlight=compatible
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Let me rephrase my question: Having a 1994 40HP Force, can I use a pre-1992 lower unit without major alterations? If so, what are the "issues"?
The 1992 to 1994 are "the same" regarding parts (by part number). The part numbers for all the components from a single year of pre-1992 lower units do not match 92-94. However, of the components I need, from 1974 to 1991 I could get the parts.
Are the lower units so similar between 1974-1994, that they are easily interchangable?
The post-94 models use a Mercury thru-hub exhaust lower unit, so I assume they are not compatible.
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Previous question:
I need to find a replacement lower unit for a 40/50HP 1994 Force ("by Mercury").
I am having trouble identifying motor years and models that could act as a parts donor.
The upper portion of the two-piece ?lower unit? is split/cracked top to bottom on the leading edge, and unservicable. Obviously, getting the part from a lower unit of a 40/50HP from 92-94 would work, but they are not common in my area, and I?m late when they are available. I want to know if other options exist.
The damaged piece is part number 817871A3. Sometimes called ?Driveshaft Housing Kit?, or ?Upper Gear Housing?. When I check ?also used on these models? feature of some websites, the model number also references 1974 thru 1980 motors in 35, 45, and 55HP. Models from 89-91 (early 92) have the same lower gear housing.
- Parts (vast majority) from 1992 (post Merc acquisition) thru 1994 are the same.
- The 89-91 lower-half gear housings have the same part number as 1992-1994.
- The 89-91 drive shaft and Upper Gear Housing do not have the same part number as 92-94.
- The 74-80 part has the same number as 92-94.
- The 74-88 lower unit housing has a different number.
So, can I use an Upper Gear Housing from a 89-91 Force, or a 74-80 Chrysler? Will I also need to change the drive shaft if I use a 89-91 Force Upper? Heaven forbid, would any (complete) lower unit, 74-94 be a slap-on fit?
Is the 89-91 Force part number difference only because of paint color, or something more significant given a driveshaft part number change? I understand that a lower unit from 1974 thru 1980 would need to be repainted to look appropriate, but I?d be more interested to know if it really is the same part, or there is a difference in the dimensions of the same part number from different decades.
Clear as mud, eh?
Thanks
After another couple of hours reviewing Force forum posts, I found a reply to my question. For my 1994 Force 40HP motor, compatible lower units are found in 1984-1994 25HP to 50HP motors. Master roscoe found the information in his "manual". Thank you Master roscoe.
http://forums.iboats.com/showthread.php?t=151572&highlight=compatible
********************
Let me rephrase my question: Having a 1994 40HP Force, can I use a pre-1992 lower unit without major alterations? If so, what are the "issues"?
The 1992 to 1994 are "the same" regarding parts (by part number). The part numbers for all the components from a single year of pre-1992 lower units do not match 92-94. However, of the components I need, from 1974 to 1991 I could get the parts.
Are the lower units so similar between 1974-1994, that they are easily interchangable?
The post-94 models use a Mercury thru-hub exhaust lower unit, so I assume they are not compatible.
********
Previous question:
I need to find a replacement lower unit for a 40/50HP 1994 Force ("by Mercury").
I am having trouble identifying motor years and models that could act as a parts donor.
The upper portion of the two-piece ?lower unit? is split/cracked top to bottom on the leading edge, and unservicable. Obviously, getting the part from a lower unit of a 40/50HP from 92-94 would work, but they are not common in my area, and I?m late when they are available. I want to know if other options exist.
The damaged piece is part number 817871A3. Sometimes called ?Driveshaft Housing Kit?, or ?Upper Gear Housing?. When I check ?also used on these models? feature of some websites, the model number also references 1974 thru 1980 motors in 35, 45, and 55HP. Models from 89-91 (early 92) have the same lower gear housing.
- Parts (vast majority) from 1992 (post Merc acquisition) thru 1994 are the same.
- The 89-91 lower-half gear housings have the same part number as 1992-1994.
- The 89-91 drive shaft and Upper Gear Housing do not have the same part number as 92-94.
- The 74-80 part has the same number as 92-94.
- The 74-88 lower unit housing has a different number.
So, can I use an Upper Gear Housing from a 89-91 Force, or a 74-80 Chrysler? Will I also need to change the drive shaft if I use a 89-91 Force Upper? Heaven forbid, would any (complete) lower unit, 74-94 be a slap-on fit?
Is the 89-91 Force part number difference only because of paint color, or something more significant given a driveshaft part number change? I understand that a lower unit from 1974 thru 1980 would need to be repainted to look appropriate, but I?d be more interested to know if it really is the same part, or there is a difference in the dimensions of the same part number from different decades.
Clear as mud, eh?
Thanks