drilling/cutting spanner nut

[miichael18]

I have a 1976 merc 200 20hp and i cant get the spanner nut off and i had the spanner socket slip off and messed up the notches now i cant get it off. My repair manual says drill at a certain spot with a hole but my spanner nut isn't like the one in the diagram. Whats the best way to cut/drill the spanner nut out without damaging the housing threads? It is the spanner nut behind the prop that holds prop shaft in. I have dremel tool and drill I'm just scared i may mess up the threads in the housing/lower unit.

 

[Laddies]

Re: drilling/cutting spanner nut

Start with a small hole in the center of the outside ring, drill it on center and then increace the hole size intill it almost touches the hsg. Do at lest 3 holes at regular intervals. Then with a punch or chisel tap the nut towards the center and it will beak quite easily

 

[miichael18]

Re: drilling/cutting spanner nut

Thanks alot. I will give it a try this weekend. what is the nut made out of? anyone know?

 

[Laddies]

Re: drilling/cutting spanner nut

Alumium

 

[emckelvy]

Re: drilling/cutting spanner nut

The nut is typically made out of aluminum, and very easy to drill. Be careful you don't drill too far.

It helps to use a very small drill bit as you can better control the placement of the holes.

After you have everything apart, be sure to clean out the internal threads in the gearcase as they'll fill up with salt & other deposits. Test fit the new spanner nut before you reassemble the gearcase, to ensure it spins in freely. If not, you'll need to clean the threads a bit more.

BTW you may get either an aluminum or plastic replacement, either will work fine.

Slather a thin coating of Permatex No. 3 Aviation gasket dressing on the sealing surfaces of the bearing carrier and also on the gearcase threads, before you reassemble. This will keep any salt out of the joints and also make it a ton easier to disassemble if it becomes necessary in the future.

HTH & G'luck..........ed

 

[miichael18]

Re: drilling/cutting spanner nut

Is there anything else i should replace once i got it apart? Reason im taking it out is because the prop shaft seal is leaking oil.

 

[gungalunge]

Re: drilling/cutting spanner nut

i cut mine off all alumimim sliced it in two spots with dremmel