Gear case plug headache

I went to replace the gear case oil on my T9.9 for the 1st time. The bottom plug is torqued down way more than specs and it won’t loosen. (everything went fine on my hpdi 200) Thank you Yamaha for over tightening the plug and for not being modern using an outdated slotted screw and not something more “positive”. There is a reason why you can’t hardly buy a screw these days that doesn’t have at least a phillips head or better. I suppose I’ll have to take it to a dealer. I wonder what do they use? What a hassle.

Most techs I have seen do them use the Snap-On wide blade screw driver that is intended for just that use.

kroger3 wrote:

Most techs I have seen do them use the Snap-On wide blade screw driver that is intended for just that use.

X2 on the x-large screwdriver. Make sure it fits tight. Then take a vise-grip pliers and clamp down on the screwdriver as close to the screw as possible. Use the vise-grip to turn the screw while applying forward pressure to the screwdriver.

-J.

use this with the biggest flat head bit/Users/sukthaininh/Desktop/th.jpeg

sorry

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Jon Jordan wrote:

X2 on the x-large screwdriver. Make sure it fits tight. Then take a vise-grip pliers and clamp down on the screwdriver as close to the screw as possible. Use the vise-grip to turn the screw while applying forward pressure to the screwdriver.

I use a crescent wrench vs a vise grip for a little more leverage, but it is the same idea.

Yamaha isn’t the only one still using those slotted screws. I think there is probably a reason they do, to prevent OVER torque. I have a Suzuki and I cursed the first year I took them out, but now I have it down to a science. I would bet you have better luck next year than this year, but yeah, its a pain for sure.
I had looked at one time and there are some other options using allen head bolts, which I think Evinrude uses, but the key would be to find the same thread pattern and length, which I was a bit nervous about so I just take my time with what I have.

I have a set of sockets that have screw driver bits on them and they are very helpful for odd things.
http://www.sears.com/craftsman-42-piece-1-4-and-3-8-inch-drive/p-00934845000P?unitNo=0001032&sellerId=SEARS&prdNo=7&blockNo=7&blockType=G7

I use an old fashioned tire iron. The end for removing hubcaps is just right. I put all my weight on the tire iron while I have someone use a pipe wrench on it. Works great on those over tightened screws.

I also use an XL flat head socket, works great. I also have a hand impact screwdriver like Thai stated above, but I am very cautious using it on my lower unit. If it is at all marred up, replace it.

I purchased a used ATV this year and I was going to do a valve adjustment on it and noticed the timing plug was marred up good from someone trying to get it off. I ended up trimming a piece of thin sheet metal to use as a shim to fit in the slot and then used my hand impact and hammered it into the slot to make a tight fit. Once the screwdriver was in there real tight, it screwed right out.

I will throw this in the ring as everyone has said what I would anyway.

when working with aluminum or stainless steel screws that are either flat or phillips type,go to an automotive parts store and buy a small tube of valve lapping compound.

smear a little of this paste onto/into the screw head that is giving fits,with firm down pressure on the screwdriver,the screw most often will back out with out any extra effort unless over torqued by a hamfisted installer,then you may need vise grips or pliers

the reason this works is the glass/diamond grit in the lapping compound bites into the blade of the screwdriver and screw slot preventing slippage.
once the screw is loosened and before you remove it completely,clean the area with brake/carb cleaner as you do not want any of that grit in a gearbox or wherever.

have done this countless times and it has worked every time unless someone has been there and all but destroyed the screw,then its get out the drills and easy outs.

I stopped by Erickson Marine in Hastings. They had a tool like the one posted by Walleye Thai (thanks). Put the tool in the slot and hit it with a hammer and it did the trick 1st time! I ill definitely get one of these. Thanks to Erickson Marine for their help. Good guys

I have large Snap on screwdriver that has a he on the shank. You just use wrench on the shafts for more leverage. Also recommend replacing the gasket every time. Many times the water that gets in the lower unit gets in by the gasket.

captddh wrote:

They had a tool like the one posted by Walleye Thai (thanks). Put the tool in the slot and hit it with a hammer and it did the trick 1st time! I ill definitely get one of these.

I bought one (I think they’re call impact screwdrivers) at Fleet Farm last year. I think it was like $12. I don’t use it a ton, but it has come in handy several times.

On the impact driver…..you’re going to be working with aluminum case material. Are you sure you want to be hammering on it? That aluminum can crack and you may not even be aware of it until further down the road. There are sockets with screwdriver bits for use with ratchet wrenches that will turn those stubborn plugs out. I’d be very nervous about smacking that impact driver very hard.

Put a dab of anti-seize compound on the threads, tighten to spec, and you’ll never have a problem again with a regular screw driver now that you got it out once.

I also have a set of Craftsman screwdriver bits for a 3/8 drive socket that come in handy. Had there been a Harbor Freight in my area when I bought them, that’s where I would have gotten them as they’d have been much cheaper, but still a worthy investment.

Finally, if you don’t already have a torque wrench (socket drive) in 3/8 and 1/2 and you do any amount of mechanic work at all, clip a 20% off Harbor Freight coupon and go in and get the 2 socket drive models mentioned. These are TREMENDOUSLY useful for sensitive applications where messing up the threads would cause serious heartache.

Grouse