Prop shaft end play?

Slojoe

Slojoe

Seaman Apprentice
Joined
Sep 13, 2009
Messages
32
I have a 77 Evinrude 70 horse, the prop shaft moves in and out almost 1/4". I am wondering if this is normal or cause for concern. Everything else seems ok with the motor. Any advice is appreciated.
 
W

Will Bark

Lieutenant
Joined
Aug 1, 2010
Messages
1,470
Re: Prop shaft end play?

A Joe Reeves or F-R will have to chime in but my 77 15hp Rude and 87 150 johny both have that much play in them with no problems ever; I would think there has to be some movement in them.
 
E

EN2

Chief Petty Officer
Joined
Nov 19, 2007
Messages
404
Re: Prop shaft end play?

MY 88 40hp has about the same.
 
metriccrescentwrench

metriccrescentwrench

Commander
Joined
Oct 22, 2007
Messages
2,598
Re: Prop shaft end play?

That little bit of movement is just a fact of life because of the design. I think everyone who's getting started out working on their own engine eventually notices that play and wonders about it. After I had a couple of lower units apart it became obvious where that play is coming from, and that it's normal.
 
J

jeffersondodson561

Ensign
Joined
Oct 28, 2010
Messages
923
Re: Prop shaft end play?

OMC just measures pinion and forward backlash, as far as I know Suzuki and Yamaha are the only ones that had a spec for propshaft endplay.
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: Prop shaft end play?

Are you sure it is the prop shaft moving and not the prop sliding on the shaft? The latter could indicate a missing thrust washer, and if it is the forward one that is missing will have disasterous results. (never assume)
 
J

jeffersondodson561

Ensign
Joined
Oct 28, 2010
Messages
923
Re: Prop shaft end play?

F_R said:
Are you sure it is the prop shaft moving and not the prop sliding on the shaft? The latter could indicate a missing thrust washer, and if it is the forward one that is missing will have disasterous results. (never assume)
Click to expand...

This is a very good point, have seen numerous times the prop just secured by the cotter pin. Prop nut torque should be tight, refer to service manual but I would think that the nut should be torqued to 40-50 foot/lbs.
 
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