Lower unit shaft swap

[afojc]

How difficult is it to swap out lower unit shafts and can it in fact be done......The lower unit in question is a fine spline and it needs a 4 spline to work with my power head. Thanks in advance.

 

[Chris1956]

Re: Lower unit shaft swap

You need to post the model and year of both LUs.

 

[afojc]

Re: Lower unit shaft swap

The power head is a 1987 70 HP and the lower unit is a 1990 70 hP

 

[Chinewalker]

Re: Lower unit shaft swap

It is best to have a shop do the swap as there is some gear meshing that has to be set to spec with a gauge. A new shaft may be off a bit which could lead to premature gear failure due to the pinion gear riding too deep or shallow in relation to the other gears. I rebuilt my 90hp lower unit and paid the shop guy $20 to set the shaft depth for me... The rest is easy, but you'll need a big honkin' pair of snap-ring pliers to get the snap-rings in and out.

- Scott