driveshaft - propeller - backlash??

dodl

Seaman Apprentice
Joined
Nov 9, 2003
Messages
49
Hello,<br /><br />I have an old Mariner 20HP here and when i pulled off the lower unit to change impeller and gaskets, i found, that i can move the driveshaft pretty much when in gear, before the propeller starts moving. Has this to do with backlash? In the manual they write about 0,5-0,7mm when measuring backlash. I can turn the shaft much more. I can't believe that it is possible to put so much shimming material on the prop shaft to get the 0,5mm.<br /><br />Or is this normal and i misunderstood something here?<br />Lower unit oil is clean. No particles at all.<br /><br />thanks<br />martin
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: driveshaft - propeller - backlash??

Backlash refers to the gap between gear teeth. You're feeling that Plus the lash in the gear/clutch cogs that can easily be 1/4 turn or more by itself. You need to take the water pump apart and put the gearcase in neutral. Then you may be able to feel the gear lash. It's probably fine unless there's a lot of metal in your gearlube.
 
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