Alpha vs. pre-Alpha

[FreeBeeTony]

I just seperated the outdrive from my '84 Grady.<br />Was going to replace the impeller and housing.<br /><br />This is the first time for this outdrive for me....just bought it last year.<br /><br />It appears to be an Alpha: flat top and more square on the back of the cavitation plate.<br /><br />When I removed the upper half. I found to my suprise the pre-load pin on the drive shaft. I was under the impression the pre-load pin was only on the pre-Alpha drives. What I did not find was the o-ring near the top of the drive shaft. Not that it was missing.......didn't look as though there is a proove in the shaft for it.<br /><br />Is it possible there was a cross-over in years. I'm pretty sure the Alpha's started in '83 or '84.<br /><br />Also found a large amount of sand in the front near the shift bushing.<br /><br />At least the lube was clean and clear....no water.

 

[Bondo]

Re: Alpha vs. pre-Alpha

It appears you have the "R" drive....<br />This 1,.....<br /><br />

<br /><br />This is the "MR" drive,.....<br /><br />

<br /><br />They're Both listed from 1983 to 1990......Ser.#s 6225577 THRU 0D469858......

 

[FreeBeeTony]

Re: Alpha vs. pre-Alpha

Thanks Bondo......here are a couple of pics.<br /><br />What about the missing o-ring?<br /><br />Anything else I should be aware of?<br /><br />

<br /><br />

 

[MrBill]

Re: Alpha vs. pre-Alpha

The Alpha One is the redesigned version of the MR drive. Only during the first year of production was the Alpha One gear housing identified with an "A" stamped on the end of the propeller shaft. The pre-load pin is absent on all Alpha Ones, but MR's are interchangeable. The Aplha One began production in 1986.

 

[Bondo]

Re: Alpha vs. pre-Alpha

Dunno,...... Maybe it's an Updated Shaft,.. Rebuilt Lower,..??....<br /><br />I know the the Oring was deleted in the later models,..... Seems it's Unnessessary,+ a Fracture Point,........<br />I've Snapped a drive at that Exact Point before........<br /><br />I Dunno Tony,........ I Don't see anything Bad there......

 

[FreeBeeTony]

Re: Alpha vs. pre-Alpha

The water pump kit I ordered was for the Alpha...was this the right choice?<br /><br />Should I be concerned about the o-ring?<br />What about the pre-load pin?<br /><br />Rebuilt lower? I like the way that sounds.....

 

[Bondo]

Re: Alpha vs. pre-Alpha

Originally posted by BabylonBoater:<br /> The water pump kit I ordered was for the Alpha...was this the right choice?<br /><br />Should I be concerned about the o-ring?<br />What about the pre-load pin?<br /><br />Rebuilt lower? I like the way that sounds.....

You Should be Fine,...... Forget about the Oring......<br /> Go over Here,+ Look up the Part #s......... <br />What About the Pre-Load Pin,..??.... Put it Back Together........

 

[FreeBeeTony]

Re: Alpha vs. pre-Alpha

Thanks Bondo........<br /><br />One more thing.....when looking for the o-ring in the uppper housing......I put my finger in the seal in the upper housing.......felt a little loose.....but I guess it's ok if there was no water intrusion.<br /><br />Guess I look in to things too deeply........

 

[muc]

Re: Alpha vs. pre-Alpha

Looks like you have an alpha 1 upper and an R lower that has had the drive shaft replaced.<br />When you remove the water pump base you will be able to see if you have bearing #21 or bearing #17 ( see how #17 has a screw in retainer and #21 doesn't) if I remember right they use a different water pump base part number.<br />Good luck muc

 

[FreeBeeTony]

Re: Alpha vs. pre-Alpha

Removed the water pump base......looks like I got the wrong one.......<br /><br />the one I recvd in the kit is too big....won't fit.<br /><br />Bondo was right (again), I have the "1" drive according to the bearing under the water pump base.<br /><br />Guess I need to get the right base...... <br /><br />Thought I had an Alpha.....so is the lower considered a pre-Alpha?

 

[Bondo]

Re: Alpha vs. pre-Alpha

Originally posted by Bondo:<br /> It appears you have the "R" drive....<br /><br />

I guess you could call it the "Almost Alpha" drive.........<br /><br />It's Not the old Model 1, or 888, or old 470s, or Any of the Other badges it wore....... The 1 with the "Eye".......

 

[FreeBeeTony]

Re: Alpha vs. pre-Alpha

You're right.........my mistake......you did say the 'R' drive.<br /><br />What do you think about the seal in the upper?

 

[Bondo]

Re: Alpha vs. pre-Alpha

What do you think about the seal in the upper?

I Dunno,.......<br /><br />That loads from the side you're Looking at, Doesn't It,..???....<br /><br />Go ahead,+ Pop 1 in, If you're at all concerned about it.......<br />I wouldn't worry about the Missing Oring Groove,.... That's a Good Thing.......

 

[FreeBeeTony]

Re: Alpha vs. pre-Alpha

I think it loads from the topside........<br /><br />Will look at it again tonight more closely.

 

[dubs283]

Re: Alpha vs. pre-Alpha

It is most likely that, yes, you do have the "R" drive. Merc made the I-R drive 1983-1984. The driveshaft housing had the same appearance as the Alpha, but the "R" drive had an MC-I gearcase, which explains the preload pin on the driveshaft. In 1985 the MR drive came out which is an Alpha One with a different name. It is a whole different animal from the MC-I and the I-R. The water pump you need is the smaller plastic one, not the newer steel large Alpha water pump housing. If you post a serial number this will provide the most conclusive evidence of what you have.