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Alpha 1 rebuild

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Jwotnac

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This is my first rebuild. Got all the tools but I ? The small grove below the upper drive shaft spline. Not the o ring grove probably caused by the oil seal. Over the years. Can I still use the shaft it’s not bent or lathe the shaft to clean it up. Or leave alone. Is there larger oil seal to compensate the wear. Drive shaft are crazy expensive
 
If the shaft is worn below the o-ring groove, then your choices are:
1) Machine shop to flame spray & machine it to size...
2) Use it as is. That seal keeps water out of the splines. The seal above keeps oil in upper housing.

Both seals are put in "lips up". Considering that you are forcing the o-ring thru that seal on assembly, & pulling it back thru on disassembly (for example when doing an impeller change) I don't feel small wear is important. But I'm not seeing it 1st hand.
 
Jwotnac said:
This is my first rebuild. Got all the tools but I ? The small grove below the upper drive shaft spline. Not the o ring grove probably caused by the oil seal. Over the years. Can I still use the shaft it’s not bent or lathe the shaft to clean it up. Or leave alone. Is there larger oil seal to compensate the wear. Drive shaft are crazy expensive
Click to expand...
You could also look for a good used one- I finally put my boat on the water in Aug, 2023 after repairing the damage from the previous abuser and when I went to my garage a few days later, saw a puddle of gear oil on the floor, so I lowered the drive and left it for later after checking the gear oil for water (it had none). I need the retainer tool and have had too much to do in the meantime, but after watching some videos, I'm assuming the shaft has a groove since the boat was made in 1984 and maintenance seems to have been a foreign word to the guy. I looked into the top when I checked it and everything looked good, but somehow, one of the four bolts was bent.

Define 'expensive' for the upper drive shaft- I found the range is $35-$100. It's highly unlikely that it's bent.

One of the videos I watched had the guy saying that the seal can be shifted slightly so it's on the larger diameter of the shaft (i.e., not pressed in completely)- it's not there to make sure the shaft doesn't move, so that could be a workable solution.
 
My 1st reply was based on the assumption you have an Alpha gen 1. I based that on the fact you mentioned the o-ring groove. Later Alpha gen 1 were made without the o-ring groove and are interchangeable. More than 1 early driveshafts snapped there, primarily V8s.

If I am correct, then that seal keeps water out only. The oil seal is bigger, about 1 inch higher and rides on the gear hub outer diameter. So a groove worn in shaft, worn seal or even missing seal will not leak oil. Note that I am not discounting the shaft wear as not important but not where the oil comes from. Because of this design, dropping the lower 1/2 for example to change the impeller will only leak oil at the small oil passage.

The gear however is an assembly of gear/lower hub part and the shaft pressed into the top of the gear with a small (thin walled) o-ring at the interface. The o-ring is does not have any relative movement and probably could leak filling the cavity with oil. I've never seen one leak.

For reference, Alpha gen 2 had a design change and the splines were in the oil reservoir. Because of this design, dropping the lower 1/2 for example to change the impeller will leak oil at the small oil passage & have it rush out at the shaft area too.

What bolt is bent? The only 4 I recall hold the water passage in place. No oil involved there.
 
Droid said:
My 1st reply was based on the assumption you have an Alpha gen 1. I based that on the fact you mentioned the o-ring groove. Later Alpha gen 1 were made without the o-ring groove and are interchangeable. More than 1 early driveshafts snapped there, primarily V8s.

If I am correct, then that seal keeps water out only. The oil seal is bigger, about 1 inch higher and rides on the gear hub outer diameter. So a groove worn in shaft, worn seal or even missing seal will not leak oil. Note that I am not discounting the shaft wear as not important but not where the oil comes from. Because of this design, dropping the lower 1/2 for example to change the impeller will only leak oil at the small oil passage.

The gear however is an assembly of gear/lower hub part and the shaft pressed into the top of the gear with a small (thin walled) o-ring at the interface. The o-ring is does not have any relative movement and probably could leak filling the cavity with oil. I've never seen one leak.

For reference, Alpha gen 2 had a design change and the splines were in the oil reservoir. Because of this design, dropping the lower 1/2 for example to change the impeller will leak oil at the small oil passage & have it rush out at the shaft area too.

What bolt is bent? The only 4 I recall hold the water passage in place. No oil involved there.
Click to expand...

You should really avoid discussing drive design that has nothing to do the original post and issues. It only adds confusion for the original poster.

He is dealing with pre Alpha. Stick with pre alpha discussion.

Pre alpha had a oring groove and a preload pin at end of vertical drive shaft.

MR was the first release of what became the Alpha Gen 1 and NO preload pin. MR had the Oring grove and when they officially started calling it Alpha, they lost the Oring grove.
 
As I went back & read again it seams I'm now replying to 2 people about 2 different boats.

As far as "4 bolts" - are you referring to the 4 that hold the cap on? How could even the worst DIYer bend one of those? Any leak there would be visible extermally at the cap. My earlier reply was assuming looking up into the bottom of the housing cavity.
 
Oops, He said Alpha 1...my bad
I also got confused as there are two or more active threads with pre alpha drive issues and questions....ugh
 
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