Transmission Drain Plug Problem

[gt3r]

I decided to change my tranny oil in my 85 carerra today. The side filler plug came out without a problem but when I went to drain the oil out of the bottom plug, the exposed portion of the plug sheared right off and now all I have is a plug which is level with the transmission case. (totally flat) My question is how do I now get the plug out??? Any suggestions would be greatly appreciated.

Regards
Mike

[Early_S_Man]

I have to assume that you didn't clean the hex recess, or have the wrench/bit fully seated before putting the full torque on the drive bit or wrench! There is quite a portion of the hex reccess up inside the case!

Clean the plug, and tap the drive bit with a plastic mallet to fully seat the drive bit ... before applying torque the second time!

[gt3r]

Actually I did clean out the plug. The drain plug recess was not nearly as deep as the fill plug. There is no hex recess left. The plug face is totally flat now. It seems that the recess was only about 1/4" deep to start. Maybe it was an aftermarket plug which was replaced by the previous owner. Any other suggestions???

Thanks
Mike

[Jim Sims]

Well, first thing is to buy a new drain plug while hoping the last guy who tightened the sheared one didn't "lean" on the wrench.

Three ideas but all require rear of car has to be jacked up and put on jack stands so there's enough room to get a drill motor under the tranny; a drill motor with a right angle drive head will reduce the required jackstand height.

Here's the first thing I'd try if it were my problem: Center punch, hammer, longer punch with sharp point, small twist drill bit (around an 1/8" of an inch in diameter), drill motor and safety glasses required. Put on the safety glasses. Use the hammer and center punch to make a small dimple into the flat sheared off face of the plug. This dimple should not be at the center but over towards the edge but not so far over as to be too close to the threads. The divot will be used to locate and steady the drill bit and if you're too close you may drill into the threads which you do not want to do. If they're the same size, inspect the root of threads on the fill plug to gain some idea how close you can get to the edge before the drill would hit the threads then come back towards the center one and half drill diameters. After the dimple is made, drill up into the dimple with the drill bit and drill motor and make a hole 1/8 " deep or so. Then catch the edge of the hole with the sharp point of the longer punch and position the punch so that it is tangential to the outer diameter of the plug and as parallel to the sheared of surface as possible while still catching the hole. Also orient the punch so hitting it will drive the plug in the counter clockwise direction (loosening direction) when looking up at the plug. Hold the punch steady and hit it's end with the hammer (remember to wear the safety glasses). The blows hopefully will cause the plug to loosen and begin the turn. If this joyous event occurs place your oil catch pan underneath the plug and then put the pointed end of the center punch or the drill bit into the drilled hole and use one of them to "crank out" the plug. Followed by a stream of foul smelling tranmission oil. If this doesn't work there are other approaches involving left hand drills or "easy outs". Good luck, Jim

[targa80]

Another possible solution would be to use a Dremel drill with a small cutting wheel. You can cut a slit into the head of the remaining plug. Cut the slit large enough to use a large size screw driver to fit into the slit. I have screwdrivers that have square shanks that I can use a wrench on to provide more turning torque. I have used this method to remove broken screws and bolts. Naturally avoid cutting into the threads of the case as Jim Sims suggested, Another method is to drill out the center of the plug and use the appropriate EZ-out bit.

[A Quiet Boom]

And as a last ditch effort, I've done this:

Find a nut that is similar in OD to the OD of the plug and mig weld the inside of the nut to the plug (i.e. hold the nut flat against the plug with pliers and weld up the hole) you do't need much weld just enough to hold it, then while it's still hot unscrew it. The problem with this is you need to be careful how much heat you put into it and it's upside down welding so you'd need an experienced welder to do it for you. Try the other methods first but remember if you drill through the plug to use an easy-out you'll have to be very careful to flush any filings out of the tranny.

[gt3r]

Thanks for all of the suggestions. I tried them all in the order presented, but the plug did not come out until I actually welded a bolt to the plug. After welding the bolt on, the plug came out with little effort, with the threads in excellent condition. Again thanks for the help. Now I'll see if Swepco 201 is really worth the $40.00/ gallon.

Regards
mike