93 Force 120 lower unit help

[Robreefer]

Hello all, long time reader, first time poster here. Any help would be much appreciated. The lower unit on my force is shot, and I need to replace it. It sounds like it's filled with marbles. My question is do I need to look for one from that exact year and hp? Or are there other years and hp models that will fit. Second question is it hard to rebuild? I am mechanically inclined, but have yet to dive into a lower unit......

 

[pnwboat]

Re: 93 Force 120 lower unit help

Looks like they used that lower end on the 120 HP from 1990 to 1994. If you don't want to do a lot of "experimenting", I would stick to 120 HP for those years.

You may be able to use one from a 90 HP from the same years (1990 - 1994), but you need to confirm the gear ratios used in the lower unit. Gear ratios are not a show stopper, but you may have to get a prop with a different pitch to achieve proper performance if the gear ratios are different.

Rebuilding the lower end is a possibility if you have unlimited funds. Parts are available but are very expensive.

 

[tavett]

Re: 93 Force 120 lower unit help

I'm no pro like these guys, but I had a similar problem with my force 125. I pulled the prop and found that one of my retaining bolts had backed out and one was being chewed up, and sounded like marbles. I cleaned up the shavings and replaced the bolts and had a summer free of reoccurence. Hope this may help. It wasn't my l/u.

 

[HAV2FISH]

Re: 93 Force 120 lower unit help

What spline count do you have and what length shaft is it?
I sent you a private message.

 

[Robreefer]

Re: 93 Force 120 lower unit help

Hav2fish, I have not received any pms..... Thank you all for your suggestions and help! It just happened this past Sunday and have not had the chance to drop the unit yet. I will be doing so this Saturday.

To give a short synopsis of what happened, I was cruising at around 30 mph, (bay was like glass) when all of a sudden the motor bogged down, then about 2 seconds later the motor freed and the rpms shot up to red line and I killed the motor. When the motor rev'd up, the boat was still slowing. (Thank god I have Sea tow). While waiting for sea tow, I checked the basics on the motor and every thing was okey dokey. Restarted the motor and it ran fine. No missing, rpm was steady, no weird noises from block. As soon as I put it In gear it dies immediately. If I put the boat in gear and try and turn the prop, it binds but doesn't stop. And makes a grinding noise.

 

[HAV2FISH]

Re: 93 Force 120 lower unit help

Sent you the PM again. You should have it now.