Loose drive shaft in lower unit Alpha1 drive?

[ottawamerc]

Hey guys

I just bought a new boat and the out drive came disassembled as the original owner planned to replace the water pump in the off season. When I was putting in the new water pump I noticed that there was some side to side play in the shaft when the pump was out? I thought it might be normal and once the lower unit was bolted back to the upper the upper gear case would support the shaft. Now that I am ready to try the boat in the water I'm starting to think that the shaft should have no play? I have seen there is a nut that needs a special tool that holds that upper bearing in place, could it have come loose? I'm afraid to run it right now incase the play causes some gear failure. Any info or suggestions would be great.

 

[oldsub86]

Re: Loose drive shaft in lower unit Alpha1 drive?

What year, engine and outdrive do you have?

Randy

 

[paultjohnson]

Re: Loose drive shaft in lower unit Alpha1 drive?

If memory serves, its normal . The cut of the gears causes that, but it tightens up when power is applied. The shaft is pushed upwards. I THINK !!!

 

[ottawamerc]

Re: Loose drive shaft in lower unit Alpha1 drive?

Oh sorry its a 1985

 

[achris]

Re: Loose drive shaft in lower unit Alpha1 drive?

If memory serves, its normal . The cut of the gears causes that, but it tightens up when power is applied. The shaft is pushed upwards. I THINK !!!

You think right.

Oh sorry its a 1985

1985 (drive is 'MR' model) was the first year the drive-shaft bearing was installed so the force of the gears trying to push apart pushed the inner race into the outer race.... Previous to that the bearing was installed so the drive-shaft had to be pushed DOWN to keep the bearing races together, and that is the purpose of the pre-load pin in the top of the drive-shafts on the 'MC-1' and 'R' model drives.

The answer, after all that, is that the movement you felt is normal...

Chris.......

 

[ottawamerc]

Re: Loose drive shaft in lower unit Alpha1 drive?

YEAH!!!!!!!! water here we come! Thanks guys for your help, happy boating

 

[paultjohnson]

Re: Loose drive shaft in lower unit Alpha1 drive?

You think right.

1985 (drive is 'MR' model) was the first year the drive-shaft bearing was installed so the force of the gears trying to push apart pushed the inner race into the outer race.... Previous to that the bearing was installed so the drive-shaft had to be pushed DOWN to keep the bearing races together, and that is the purpose of the pre-load pin in the top of the drive-shafts on the 'MC-1' and 'R' model drives.

The answer, after all that, is that the movement you felt is normal...

Chris.......

Thanks for da clarification

YEAH!!!!!!!! water here we come! Thanks guys for your help, happy boating

You welcome ! Back at ya