Wiggle in lower unit shaft

tatumd

Recruit
Joined
Sep 20, 2010
Messages
1
After taking my boat (mercruiser 4.3 alpha 1 gen 2) out on the river i got back home and after cleaning it up noticed an oil leak from water pickup. Local mechanic says lower bearing is bad. he suggest i replace entire lower unit instead of attempting to repair Showed me slack/ wiggle in shaft and feels rough when turned. if you pull up on shaft and turn no wiggle and turning shaft is smooth. I have read this is normal on alpha 1 gen 2. Should I find another mechanic?
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
Re: Wiggle in lower unit shaft

If this mechanic has the unit apart and is talking about the lower drive shaft he is wrong. the shaft is designed to be pushed upward by the gear set. Pulling the shaft upward should be no noise, letting it go downward will be a rough feel and have slack.
http://www.boatfix.com/merc/Techbk/97/97hs2.pdf
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Wiggle in lower unit shaft

Before the drive was pulled apart it should have been pressure tested to determine WHERE it was leaking. And as Bt said, that's the way the Gen II is designed (actually that design started with the MR/1985)....

Either your mechanic hasn't updated his knowledge (for 30 years!!!), or he's looking for an 'easy earner'....

Chris...
 
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