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Alph 1 Gen 2 water impeller replacement

T

tstaylor

New member
Time to replace my water impeller in my 5.0 EFI alpha 1 Gen II lower unit. Last thime this was done the shop did it for me. now it's my turn.
Is there a proceedure some replace that I can follow or just drain the oil and spilt it apart?? Do I need any special tools?? Gaskets etc.... When I bought the boat 8 years ago I went the first year on what was there. Boat was 3 years old at that time. The lower unti was using a little more oil than I thought it should so over the winter I had a shop replace oil seals and replace the water impeller. So I'm about 7 years on the one that's in there. No problems just think it's time. boat used in freash water only... skaneateles only since I've owned , water's pretty clean and deep. any info. would help thanks ...
 
Go to youtube and search for "Mercruiser alpha 1 impeller replacement". There is not much to the job. No need to drain the drive oil. Shift it into forward gear and remove the key.
 
Sorry...you don't have to drain OB lower unit gear oil because the oil is contained whereas the Alpha Gen II drive isn't. He left the plastic depth gauge for the shaft seal on the shaft...it is used only to set the seal to the correct height on the shaft so I take it off after setting the seal into place. When you are all done it won't hurt to remove the prop to inspect the prop shaft seal and remove any fishing line or debris and then relube the prop shaft and splines w/a heavy waterproof grease. Well, I guess you should check the prop shaft seal and grease it before dropping the LU because if the seal is bad you have to remove the impeller again to replace the seal...I guess it is a preference. If you don't find contaminated drive oil then do the prop last. I am going on 20 hrs of no sleep...not thinking straight! Once you have done several impeller changes it seems much easier than it looks. Recap: the gasket alingment is critical when changing the impeller including the oil seal he pointed out. Take your time and it will go well.
 
Gen 2 you need to change out the shift shaft bushing also. Doesn't hurt to do a pressure and vacuum test on the drive, before you fill it with oil.
 
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