OMC cobra outdrive ???

[Lou W]

I am getting ready to reseal an 86 cobra outdrive. The question is how important is it to use new bolts, the ones with the blue factory sealant/threadlock on them vs cleaning the old ones and using locktite.

 

[Don S]

Re: OMC cobra outdrive ???

They don't need replaced. Just clean and loctite where necessary. I use Perfectseal/aviation form-a-gasket on bolt threads to prevent corrosion.

 

[a70eliminator]

Re: OMC cobra outdrive ???

I cleaned and reused mine, they seem to be a quality grade stainless steel. I don't know why the manual specs them to be repalced? I wouldn't use locktite but rather just a daub of aviation sealant is what I used, just to prevent water from penetrating the threads.
The 6 nuts that attach the drive also spec to be replaced.

 

[Lou C]

Re: OMC cobra outdrive ???

They do say in the manual to replace the 6 nuts that hold the drive on but I've just used the OMC gasket sealer on any nut or bolt on the drive and never have had problems getting them off because of corrosion....the OMC gasket sealer (Permatex Aviation) works well even in salt water...

 

[havasuboatman]

Re: OMC cobra outdrive ???

Those six nuts that hold the drive on can be reused, but indefinetly. They are what is called a Nyloc nut. There is no lock washer used on them. The nylon insert is all that keeps them from backing off.
If you can put them on the studs by hand, past the nylon insert, they MUST be replaced. That is true with ANY nyloc nut used on your boat.
If you use locktite on those nuts you run the very likely risk of having the studs back out of the transom assy. next time you have to remove them.
DON'T CUT CORNERS!!!

 

[zbnutcase]

Re: OMC cobra outdrive ???

The only time you should replaced bolts is if they were corroded in upon removal; they might be fatigued and could break upon torquing (esp 1/4in). Nylocks should never be used more than 3 times. As a matter of course I always replace the drive nuts(with correct factory chrome plated brass one's, not SS) on customers boats. 'nutcase