#1 upper with Alpha lower waterpump question

[Alumarine]

Hi there. I have a 1980 #1 Drive serial 565xxx. I split the upper from the lower to change the water pump and it didn't make any sense to me.
I think that the upper is a #1 drive and the lower must be an Alpha.

The upper has the 565xxx serial number on it and the lifting ring on the top cover.
The lower does not have the preload pin, has the square anti ventilation plate and has what looks like a retainer nut under the water pump base.

Do I use the Upper Pump Kit 46-96148A5 (18-3517) with the Alpha Water Pump Base 46-44292A3 (18-3420)?

Thanks for the help.

 

[achris]

Yes.

 

[JustJason]

the lower is a MR

you need impeller kit 47-89984T5

If you want the base assembly, and it looks like you do, you want 46-44292A3

 

[Alumarine]

Thanks guys. Is there a difference between a MR and an Alpha?

 

[achris]

Thanks guys. Is there a difference between a MR and an Alpha?

Very little. Check to see if you have a letter 'A' stamped in the end of the prop shaft.

 

[Alumarine]

I don't think there is an A but I'll check tomorrow.
I have more pictures.

 

[achris]

Apart from the 'A' in the end of the propshaft, the drives look exactly the same.... Pictures will only confirm you have an MR/Alpha One....

 

[Alumarine]

Apart from the 'A' in the end of the propshaft, the drives look exactly the same.... Pictures will only confirm you have an MR/Alpha One....

Good one. I'll cool it with the pictures.

No "A" on the end of the propshaft. So that makes it a MR lower?
What the heck is the difference between the MR and Alpha then?
What years were the MR's out?

 

[achris]

An 'A' in the end of the propshaft would indicate an early 'MR'. It was dropped from the later 'MR' and Alpha One...

'MR' only ran in 1985. The 'Alpha One' ran from 1986 to the advent of the Gen II in 1991... The difference between an MR and an Alpha One? Marketing. 'Alpha One' sounds so much better than 'MR'....

Chris......

EDIT: Insofar as differences between models it goes something like this....

MC-1 to 'R'
Basically the same gear housing (lower), but a very different drive-shaft housing (upper)
'R' to 'MR'
Basically the same drive-shaft housing, but a very different gear housing.
'MR' to 'Alpha One'
I'm yet to find a single part different, apart from the decals.

HTH....

 

[Alumarine]

Yes, that did help, thanks. Although I had to google HTH :facepalm: