Drain and fill bolt size/removal suggestions

[bunni]

While finishing up engine rebuild I am starting to crack in to my manual transmission to check everything out in there and clean it up. To my (annoyed) surprise, the fill and drain bolts have 4 point heads, and of course, they are well stripped apart.

Can anyone recommend a good way to remove these? I've thought of drilling them out or welding on a bolt head (which might be more difficult to get done). One of the "gator grips" might work (I was going to pick one up tonight), but the bolts are practically rounded at this point.

What are the size of these bolts so I might try to replace them with something more functional? I assume they are some kind of metric pipe thread fitting, but I have no way to measure them if I can't get them out.

Thanks.

[Mark D]

I've used a gator grip before on mine and it worked really well. The plugs are tapered pipe thread if I remember correctly, although I have no idea what size they are. Probably some crazy metric size you'd have to order online. Or possibly one of the vendors would have new plugs to replace your stripped out ones.

[jmettee]

Gator Grip is what I recommend as a first try. The plugs are standard tapered pipe thread (NPT) IIRC. I think they are 1/4 or 3/8 possibly. Someone else can confirm size or you can grab 1 of each size & compare when you remove the existing plug

[David T]

If they are really mashed up a gator grip may not work. If it still looks kinda square get the adapter and hammer it on as much as you can and then, with a breaker bar it should come loose. If that doesn't work you are left to drilling it out. It is a tapered, metric, pipe plug. NEVER REMOVE THE DRAIN PLUG FIRST !!!!!!!! If you do and then can't get the level plug out you are now left with an empty transmission and you can't get the new oil in! Now the car is undrivable till you can get the level plug out! The socket adapter you want is a Snap-On PP-412 3/8 drive by 3/8 female square or equivalent. When installing the plug use some teflon tape so it isn't so hard to remove it the next time and don't use vise grips or a pipe wrench or an adjustable wrench. Those plugs can be VERY tight!
David Teitelbaum

[bunni]

It is a tapered, metric, pipe plug.

Do you happen to have the measurements of it?


...The socket adapter you want is a Snap-On PP-412 3/8 drive by 3/8 female square or equivalent....

Epic! Thanks! If I go with the stock plugs from DMC, I will make sure to get me one of these bad-boys.


...NEVER REMOVE THE DRAIN PLUG FIRST !!!!!!!! If you do and then can't get the level plug out you are now left with an empty transmission and you can't get the new oil in! Now the car is undrivable till you can get the level plug out!...

I really don't think thats going to be much of an issue...
/me looks at the open transmission dangling from an engine hoist

[Bitsyncmaster]

Welding a nut on it worked on my car but it's hard to get the weld inside the nut working under the car. The heat itself made it come loose on mine. I did the same to another D and it took an impact wrench to get it off after the nut was welded on.