1957 Fleetwin 7.5 parts interchange?

[W_Guy]

Hi,

What years (and HP) lower unit parts will interchange with my '57 Fleetwin 7.5hp? (housing, skeg, driveshaft, gears, etc?)

Thanks

 

[1946Zephyr]

Re: 1957 Fleetwin 7.5 parts interchange?

5.5hp of the same year. 56 - 58 on the 7.5, possibly 54 and 55. There may be later years on the 5.5's, but that depends on when they started the two piece shift rod.

 

[TN-25]

Re: 1957 Fleetwin 7.5 parts interchange?

Quite possibly the lower unit from a 1965 6 horse will also work. For 1966 they switched from a shear pin & shock absorber drive shaft to a rubber-splined prop without the shock absorber and purposely made the later props & earlier props unable to be interchanged. Your 7? prop will work on a L.U. up to & including the 1965 6 horse.

 

[F_R]

Re: 1957 Fleetwin 7.5 parts interchange?

Yep, any 5.5 or 7.5 up through 1965, as long as you are changing the complete lower unit. Mixing or matching internal parts may get you into trouble though.

Pre-1955 propellers may not fit newer lower units, but that doesn't seem to be an issue here. The older props won't fit over the newer gearcase bearing head. Ask me how I know.

 

[W_Guy]

Re: 1957 Fleetwin 7.5 parts interchange?

Thanks guys. The situation is this: my lower unit must have hit a rock (previous owner) and there's a hole punched in the nose that effects the lower housing and the skeg at the seam. Assuming the internals are ok, can I use a lower housing and skeg from a '56-'58 5.5hp or 7.5hp or other years as well?

 

[W_Guy]

Re: 1957 Fleetwin 7.5 parts interchange?

BUMP!
Answers please........:redface:

 

[F_R]

Re: 1957 Fleetwin 7.5 parts interchange?

The official word is that the skegs are not interchangeable because they were machined along with the upper housing and no two are exactly alike.

The shade-tree mechanic word is that they do it anyway.

Besides, if you rob a skeg off an assembley, then you have an upper housing with no matching part.

 

[W_Guy]

Re: 1957 Fleetwin 7.5 parts interchange?

YIKES!!!! OK, so I know I have to buy a whole lower assembly to fix my busted one.
'56-'58 only...........right???

thanks for the help...

 

[samo_ott]

Re: 1957 Fleetwin 7.5 parts interchange?

The official word is that the skegs are not interchangeable because they were machined along with the upper housing and no two are exactly alike.

The shade-tree mechanic word is that they do it anyway.

Darn tootin'. I'll slap any skeg on an upper and with lotsa 3M in there it'll work fine!

 

[1946Zephyr]

Re: 1957 Fleetwin 7.5 parts interchange?

YIKES!!!! OK, so I know I have to buy a whole lower assembly to fix my busted one.
'56-'58 only...........right???

thanks for the help...

If you have an inside micrometer, then bolt the halves together and measure the holes left and right and up and down make sure there isn't a difference. Also make sure there isn't a step to catch your nail on, in the hole. Truth be known, you'll find that there is a bearing insert that fits in the holes, so matching things up, really isn't an issue. It's all in how much sealer you use, as sammo_ott would put it and they are made pretty darned close in specs, from one to the other. They mold each piece in the same mold at the factory, then they mount them together, then they do a finish bore, to match the sets.

 

[F_R]

Re: 1957 Fleetwin 7.5 parts interchange?

YIKES!!!! OK, so I know I have to buy a whole lower assembly to fix my busted one.
'56-'58 only...........right???

thanks for the help...

No, 1955 up through 1964-ish 5.5, 6, 7.5hp will work. Not sure of the exact cut-off year without researching it.

 

[W_Guy]

Re: 1957 Fleetwin 7.5 parts interchange?

Thanks FR I wanted what years to shop for to replace my busted housing. Since there's a hole right in the nose of the gearbox I guessed there might be damage to the internals as well.............so I just bought a complete used lower unit ($50.) on ebay. That way I'll also have matching cases (I hope) + parts if needed.

BTW, I like the fingernail idea. That's a pretty easy way to tell if the 2 surfaces are true to each other.

THanks again
Verne