Bent Prop Shaft - Alpha One Drive

Limk

Cadet
Joined
Jun 8, 2010
Messages
7
Hi Guys

I have 1998 Searay 190 with a 4.3L Mercruiser Engine and an alpha one outdrive. The serial no of the drive is 0F095817.

I recently hit a rock with my prop and not only did i damage the prop but i also bent the shaft.

So guys what are my options here?

1. Can i replace the shaft? If so, i take it a i need to remove the lower unit from the upper drive unit to get the prop shaft out.

2. Can i straighten the shaft? The shaft is visibly bent when you rotate it!

3. Do i need to replace the complete lower unit?? I hope not! If so i'll be off the water for some time as my budget will not allow this i'm afraid...

I started to take a look at it last night and removed the prop and parts as far as the bearing carrier (item 58 in the manual). I wil need to borrow a suitable pullers as my own isnt long enough to remove the bearing carrier.


Any advice would be greatly appreciated.

Thanks
Limk
 
Joined
Mar 27, 2010
Messages
3,008
Re: Bent Prop Shaft - Alpha One Drive

Unfortuantely,
a new prop shaft as around $300.00. The lower has to come off and be completey disassembled and reassembled which includeds setting shims and clearances which require special tool to do it. If it is not correct the gears will be destroyed. If you pay to have it done it will cost as much if not more than a new aftermarket lower.

You can try shop around for a used one, they are always on ebay, and hope to get a good one, (there are SOME good sellers on there).
Or get a new SEI lower and bolt it up to your upper.

I damaged my prop shaft with wire line getting wrapped around it and the cost to replace the shaft was not worth it. (Alpha one gen one)

Good luck with it,
Eric
 

Limk

Cadet
Joined
Jun 8, 2010
Messages
7
Re: Bent Prop Shaft - Alpha One Drive

Thanks for the feedback Eric.

I'll have a look and see if i can source a secondhand lower section which may be my best option.

On the other hand has anyone here succesfully managed to replace the prop shaft? I am currently looking through the manual but dont see a proceedure for it. If i thought it was possible i might try and give it a shot??

Thanks in advance for replies
Limk
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,130
Re: Bent Prop Shaft - Alpha One Drive

The lower has to come off and be completey disassembled and reassembled which includeds setting shims and clearances which require special tool to do it.

Ayuh,... Limk,... By your statements, it sounds like the task is Way over your head...
It takes Special Tools, as well as the Special Knowledge to get it Right...
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,360
Re: Bent Prop Shaft - Alpha One Drive

plenty of times but they wouldnt listen to me when I tell them that the shock of the impact was transmitted all the way to the coupler.This is another reason I like aluminum props. There like a cheap insurance policy. 2 days -2 years they come back with broken gears, broken driveshafts, and claim the never hit anything.

pull lower, remove water pump, drive shaft bearing nut(special tool) ,remove lower carrier, remove pinion nut while holding upper driveshaft(special tool), remove pinion, remove driveshaft, wiggle prop shaft to clear shift selector and remove. remove dog spring ,pin ,shift spool, fwd gear and bearing. and you have the shaft.
Sounds easy ,BUT without the special tools and adequate knowledge to disassemble
and reassamble with all the clearances it`s a 1st Timers Gamble.

a prop shaft is about 300, a new lower with a 3 year warrenty is $600 ish.
 

Limk

Cadet
Joined
Jun 8, 2010
Messages
7
Re: Bent Prop Shaft - Alpha One Drive

Any suggested suppliers for a new lower section. I had a look and most seem to be in the $800 range.

I assume that mine is a standard rotation! How do I tell? The serial no of my alpha one drive is 0F095817 1.84R which i assume means the ratio is 1.84. Also based on the serial no. i think its a GenII??

Do i need to ensure that i order a lower section with a ratio of 1.84 or are all of the alpha one lower sections compatible?

Thanks Limk
 
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