Alpha lower with pre-load pin...

[No Worries]

Is this possible? I did the impeller kit today and it was odd that the impeller base didn't fit. Sierra #18-3320. The shaft has the pre-load pin on it but the lower half is visually an alpha.

 

[FreeBeeTony]

You probably have a MR drive..........

 

[No Worries]

You probably have a MR drive..........

I thought an MR was an alpha. Do you mean an R?
An R lower with an alpha upper? Is that possible?
The upper is definitely alpha. Thanks.

 

[Bondo]

An R lower with an alpha upper? Is that possible?

Ayuh,.... Unit for unit, uppers, 'n lowers can be shuffled like cards, mix, 'n match 'bout anyway ya want,....
MC-1 upper or lower will work perfectly with a R, or MR, or Alpha 1,...
Both forwards, 'n backwards compatible, right up to '91, 'n the Gen.II drives, which don't interchange with any of the previous Alpha series,...

 

[No Worries]

No Title

Ayuh,.... Unit for unit, uppers, 'n lowers can be shuffled like cards, mix, 'n match 'bout anyway ya want,....
MC-1 upper or lower will work perfectly with a R, or MR, or Alpha 1,...
Both forwards, 'n backwards compatible, right up to '91, 'n the Gen.II drives, which don't interchange with any of the previous Alpha series,...

I have an '84 SeaRay Seville and have been told it's still considered a "pin drive". It looks just like an alpha but the impeller base from the alpha one gen one kit I bought didn't fit.

 

[Bondo]

It looks just like an alpha but the impeller base from the alpha one gen one kit I bought didn't fit.

Ayuh,..... Must be an R, or MR,.....

There's 2 other water pump kits, the one without the water port(which I think is what you want),....
'n the one with the water port, which is for much older MC-1s,...

 

[Bt Doctur]

that number comes back as MR/Alpha1 drive ,used in drives without the preload pin
should have been 18-3317 no flushing port

 

[achris]

R, MR and Alpha One all use the same upper. No difference externally or internally...
If the lower has a pre-load pin it's an MC-1 or an R. MR and Alpha One (identical internally and externally) have NO preload pin.

As far as the housings go, for the outside, R, MR and Alpha One look pretty much identical. It's very possible the original lower was damaged and someone replaced it with an R...

Chris......

 

[shughes12]

Ayuh,.... Unit for unit, uppers, 'n lowers can be shuffled like cards, mix, 'n match 'bout anyway ya want,....
MC-1 upper or lower will work perfectly with a R, or MR, or Alpha 1,...
Both forwards, 'n backwards compatible, right up to '91, 'n the Gen.II drives, which don't interchange with any of the previous Alpha series,...

Long shot on an old thread. I got a replacement drive that has the pin but my old leg doesn't have it, can I still use it?