1988 125 hp force prop/lower unit

[Knighteric38]

I have a 1988 Force outboard 125 hp I am getting a clunking noise from the lower unit and the prop has a inch or two of play is my lower unit toast?

​

 

[The Force power]

When do you get "the clunking sound" ? when you put it in gear?
What "play" do you mean? clockwise/ counter clockwise?

 

[Knighteric38]

It's only in gear and as far as play it's in and out on the shaft

 

[jerryjerry05]

IF???? you can pull the prop shaft out 1 -2 inches??
Then your lower is probably shot??
Try taking it apart.

Where you located?

 

[The Force power]

Check if the hub-spacer is behind the propeller, is the nut tied?

 

[Knighteric38]

I am in Hillsboro N.D. and I have taken the nut off and there is a spacer between the nut and a toothed spacer nothing behind it

 

[Knighteric38]

And the prop shaft does not slide in and just the prop

 

[Knighteric38]

 

[Nordin]

Please confirm that the prop is sliding at the prop shaft or is there a play in the prop shaft.
If you try to pull in at out at the prop shaft, do you have a 1-2 inch play?
If not and only when you have the prop mounted at the prop shaft you need a spacer/washer behind the prop and the prop nut.
The collar at the prop should slide in a bit into the gear case, if you have a gap there the prop can cavitate if you have adual exhaust gear case.
The exhauste will go out infront of the prop.

 

[Knighteric38]

When I had the prop off I pulled on the shaft and no play only the prop sliding and as far as a washer there is a nut then a washer then a toothed spacer that slides on the shaft then prop no washer behind the prop

 

[Nordin]

General there use to be from gear case and out, first a thick spacer plate with a taper in the hole fitting the taper at the prop shaft, the prop, the toothed washer and then a thinner washer and then the prop nut.
If the hub in the prop is shorter you have to put an other washer or a thicker washer between the toothed washer and the nut or between the spacer and the prop.
The spline at the prop shaft and in the prop hub may not fit correctly.
But be sure soo there will be a small gap between the gear case and the prop.
Otherwise the prop will grind at the gear case.
If you have the dual exhauset gear case the collar at the prop must slide a bit into the gear case body.
If not the exhaust will leak through the gap and it will cavitate.

 

[jerryjerry05]

Pics of the pieces on the prop and shaft where it comes out the lower unit?
Also the area on both sides of the prop.
Sometimes the thrust hub gets stuck to the prop and looks like it's made there.

The prop shaft should have a little bit of play. 1/8 to 1/4" in and out play.

 

[Knighteric38]

So I think what everyone is saying is that I am missing a washer between the gear housing and the prop? If so will any washer work or do I need to find a dealer or scrap yard that has one?

 

[Nordin]

Use a washer with large outer diameter (the same as the spacer would be best) and a hole that fits the prop shaft with not to large play.
The thickness would be large enough to tight the prop with out any play to the prop shaft.
A stainless one would be the best but if you use a one from iron coat it with grease and pull it off every autumn and grease it.
Otherwise it will rust.

 

[The Force power]

I would have to disagree, because the bore-hole on "the Spacer" is tapered for a snug-fit; a plain washer/spacer will bite into the shaft & the prop will not stay on straight.

This is what you need

 

[Nordin]

I believe he has that spacer but need another one to fill out the to get a gap to the prop and to the gear case housing.
Then fill out the play in the prop shaft.
Do not know if he has the dual exhaust LU or the single one.
If dual he need to get the prop to slide a bit into the gear case housing to avoid cavitation.

 

[The Force power]

True that, an real '88 would still be single-exhaust
He could use that Spacer, if he remove the anode

 

[jerryjerry05]

Post pics of the pieces you have????
That saves a lot of ???????
Without the right parts you can destroy the lower unit.
The pic that the force posted shows a hub that MUST be there.

 

[Knighteric38]

Sorry got busy with my house will try and post pics in the next few days I think that the piece that the force posted is not there I will check in next few days thank you for all of your help everyone

 

[The Force power]

As Jerry mentioned already; sometimes they're stuck in the prop, so for an untrained eye it looks like its not there.
Pictures most times say more than a thousand words. lol