Need suggestions on removing lower unit drain screw

[Mark42]

Went to change the lower unit oil a few days ago and the slot head screw is in there tight! I slipped twice with the largest blade driver I have and I don't want to mess it up. Is there any trick on getting it out other than tapping with hammer or heating? I used to have an impact driver, but I just can't find it. Maybe I should pick up another. <br /><br />I am annoyed that this o/b was rebuilt in 2003 and that plug was out for draining and filling so it shouldn't be corroded or overtightened. So why doesn't it come out?

 

[Geoff Smith321]

Re: Need suggestions on removing lower unit drain screw

Went to change the lower unit oil a few days ago and the slot head screw is in there tight!<br /><br />I will be very interested to hear any suggestions for this problem because I have the same one.<br />Cheers my friend.

 

[Chinewalker]

Re: Need suggestions on removing lower unit drain screw

Impact driver - only way to go....<br /><br />- Scott

 

[rayjay]

Re: Need suggestions on removing lower unit drain screw

If the adaptor and bits from the impact driver are still in your tool box then you can just use a 3/8" drive ratchet to get some extra leverage. Definitely use a large screwdriver bit that is the full width of the slot. <br /><br />Better a too tight than too loose !

 

[Paul Moir]

Re: Need suggestions on removing lower unit drain screw

I agree 100% with Chinewalker. An impact screwdriver is the only tool to use. Works much better than just putting leverage on a bit.

 

[Mark42]

Re: Need suggestions on removing lower unit drain screw

I found a old large (and I mean wide driver end) all steel screwdriver, cleaned and squared up the end on a bench grinder so it was a snug fit on the screw heads. A few taps from a hammer and they came loose. I did NOT pound on them. <br /><br />Drained the oil and it is a dark navy blue color. What I am replaceing it with is Super Tech Marine brand and it is typical honey colored gear lube. Any idea what brand the dark blue lube is? Im wondering if it was synthetic or better than what I am replaceing it with.<br /><br />Edit: Corrected brand name of gear lube.

 

[Geoff Smith321]

Re: Need suggestions on removing lower unit drain screw

Thanks for this info everyone, at least it shows it can be done.

 

[Mark42]

Re: Need suggestions on removing lower unit drain screw

Why the designers used a slot headed screw is beyond me. Tightening and loosening is much more prone to slipping with a slot than a phillips, torks or simple cap head screw (my vote!). I'm going to keepan eye out for a magnet drain plug in stainless or aluminum with cap head or alen heads to replace these troublesome slot head screws.

 

[rdh2059]

Re: Need suggestions on removing lower unit drain screw

One more way of removing a stuck drain plug is to heat the plug and surrounding metal with a propane torch. You've probably got some crud or corrosion in the threads. Heating both the plug and the surrounding metal, compress the crud, giving you a better chance of getting them off. Also you might want to combine heading with using penetrating oil on it after it cools. If all else fails, you can use a drill and screw extractor, but IMO unless its a bolt thats worn due to corrosion, the torch usually solves the problem...<br /><br />Rick

 

[McGR]

Re: Need suggestions on removing lower unit drain screw

The blue color lube doesn't necessarily signify the type of lube. I forget which brand, but one of the garden variety l/u lubes I've used in the past is dyed blue. The honey colored Super Tech will work just fine and probably isn't any better or worse than the blue stuff.

 

[Paul Moir]

Re: Need suggestions on removing lower unit drain screw

Isn't Merc Quicksilver blue?<br />The main reason to replace your l/u oil on a smallish o/b is to check for signs of water intrusion. That's why I like to replace it in the fall before it sits all winter. Also, IMO, if they're stuck too tight for the torch or the impact driver, they're stuck to tight for a drill & screw extractor. <br /><br />Naturally, I think they should be Robby Blacks. (Phillips?? why would you ever wish that on someone?? I think I've seen combo ones on a Suzuki! ) But socket head would be ok I suppose.

 

[Mark42]

Re: Need suggestions on removing lower unit drain screw

Got to thinking about how tight I could make the drain plugs using just my screwdriver and hands. Got a bit nervous thinking about a plug vibrating loose and draining all my lube while I motor along pretending I'm piloting a 50 ft cruiser.... <br /><br />So I went out and picked up an impact driver from Sears to tighten them. Works great. They were probably installed with an impact driver by the rebuilder and I suspect they are new plugs because the only scratches on them are the ones I put there using a screwdriver. Once out they were clean as a whistle. Hope they stay that way.<br /><br />The $24 spent on the tool is cheap piece of mind.