Cobra lower gear oil drain plug stuck, now what?

[joerao]

So I attempted to change the gear oil in my 1987 Cobra lower unit. Of course, it didn't go quite as simple as some of the write-ups on the forum. Turns out that the bottom gear oil drain screw/plug is jammed and won't back out of its threads no matter what I throw at it.

I've tried torqueing it with a larger screw driver/wrench combo as well as using a bit of WD/40 to try and break it loose, no luck (wish they didn't use a flat head screw).

Looking for some suggestions on alternative ways to drain the lower unit's gear oil. I was able to get the upper drain plug out and drained almost half the oil, although its the lower half (plus any water, fingers crossed) that I'm more concerned with).

Is siphoning or pumping the oil out through the upper drain plug an option or is the risk of getting my pump tube stuck in the gears not worth the risk?

Any other options, or suggestions on getting the drain plug out, or getting the rest of the oil out without damaging the lower unit too much.

Thanks in advance..

 

[wcasey5]

Re: Cobra lower gear oil drain plug stuck, now what?

You could make sure you have a flat blade that fits the slot, I used a flat blade socket from sears and a ratchet. Alternatively you could use an impact driver, one that you hit with a hammer. And allen would be much better. Someone else may show up with a better solution.

 

[Levinz11]

Re: Cobra lower gear oil drain plug stuck, now what?

First time I changed my drive oil, I had to buy a hand-held impact driver to get that sucker out.

 

[Nivekt]

Re: Cobra lower gear oil drain plug stuck, now what?

You need one of these: Impact Screwdriver Set with Case but with the right size head to fit the screw. I use a grinded down old chisel to perfectly fit the screw head. Then I clamp on to the chisel with a pair of channel locks and turn while pushing in the handle of the chisel.

 

[Lou C]

Re: Cobra lower gear oil drain plug stuck, now what?

Impact screwdriver. Then pick a up a new set of BRP plugs that have Allen recesses. Much less likely to strip.

 

[joerao]

Re: Cobra lower gear oil drain plug stuck, now what?

Impact screwdriver. Then pick a up a new set of BRP plugs that have Allen recesses. Much less likely to strip.

Love this idea, any clue as to who stocks these for the Cobra. Google searches aren't taking me too far.

#0912624 from BRP's site show's the replacement part, but doesn't indicate allen sockets.

Also, tried some Freeze-Off penetrating oil plus an impact wrench and large screwdriver. Still no luck. Going to try the Harbor Freight Impact Screwdriver tonight and I'll post the results.

 

[Lou C]

Re: Cobra lower gear oil drain plug stuck, now what?

Find a dealer tha sells Evinrudes and they will have em the same ones are used on the late model outboards. I think all the new drain plugs from BRP use Allen style plugs.

 

[excessiveego]

Re: Cobra lower gear oil drain plug stuck, now what?

an impact screw driver will do the trick, I had never heard of one until I was searching on here for how to remove the plugs on my drive, and since then It has been one of the best purchases ive made

 

[joerao]

Re: Cobra lower gear oil drain plug stuck, now what?

You need one of these: Impact Screwdriver Set with Case but with the right size head to fit the screw. I use a grinded down old chisel to perfectly fit the screw head. Then I clamp on to the chisel with a pair of channel locks and turn while pushing in the handle of the chisel.

Quick update. Thanks! I picked up one of these at Harbor Freight and it worked perfectly. A few hard knocks with a rubber mallet on this thing and the drain plug started to budge.

This is definitely one of my new favorite tools.

 

[Gangly]

Re: Cobra lower gear oil drain plug stuck, now what?

awesome, worked for me as well. I wouldnt have known about it the impact driver if this post hadn't mentioned it, thanks guys!

 

[sharkshemp]

Re: Cobra lower gear oil drain plug stuck, now what?

So I had the same problem. First, I tried a lefty drill bit. It was the only way on a motorcycle seat bolt & worked like a charm. No such luck on the boat. It drilled out a chunk of the bolt though so I scratched my head & thought if you can pump the oil to change it, why not the gear oil too. I modified my oil pump to fit the fill (middle) bolt & pumped away. When it was dry, it took almost all new oil. Not ideal but if you can't get it out, I recommend this method. Good luck!

 

[excessiveego]

Re: Cobra lower gear oil drain plug stuck, now what?

not the best plan, If there is water in the drive it will be down at the bottom of the drive and wont come out unless you pull the lower drain plug.