Replacing nuts that hold lower unit-Force 120

[dmgray55]

I have a 1998 Force 120. I would like to replace the elastic insert nuts that hold on the lower unit when removing it to replace the impeller. I have looked everywhere trying to find what size these nuts are. At Lowes I found Grade C Nylon Insert lock nuts 3/8-24. They look like they are the same however they fit tight and I am afraid to force them on for fear of damaging the threads. Does anyone know if these are the right nuts or what the correct nut is for this application? Thanks.

 

[Frank Acampora]

Re: Replacing nuts that hold lower unit-Force 120

Seems that on later Mercs, and your lower unit is Mercury, The nuts are brass or bronze 14 MM. That would make the studs 8 or 9 MM threads. 3/8 threads will go on one or two turns and interference tighten. They do not fit so don't force them. Try Fastenal for the nuts in either stainless or brass. If that fails, Go to the dealer and pay him the first born child he requires for parts.

 

[dmgray55]

Re: Replacing nuts that hold lower unit-Force 120

You are exactly right....they go on one or two turns and then meet resistance. That is why I didn't force them. I'll check those sources and report back. Thanks for the lead.