Hi:

The fill plug for the M46 Standard in my 1986 745 is completely chewed up. I can't even get a pipe wrench on it. It was in rough shape when I got it but I made it worse with a pipe wrench.

Can anyone tell me how to remove this? I recently refilled it and I had a hard time getting it out then.

Thanks

I just went through this with mine 2 weeks ago and was ready to take it to the dealer and have the pan removed.
I soaked it with Gunk liquid wrench, then hammered on the fill bolt for about 5 min. in different directions for the vibration to let a little of the penetrating oil to work its way in there. I did this for about 4 or 5 nights, then let the car sit over night. Then used a torch to heat transmission AROUND the bolt, but trying to avoid the bolt itself. I then applied a brief clockwise force to it (yes, tightening direction) I was ready to torque it hard CCW with the pipe wrench, but by that point it came off so easy with a little click that I almost broke my knuckles.

Good luck.

I ran into this problem on a friend's M46 (1989 740 Turbo) back in Feburary. After a couple days of working on it in the snow, we finally gave up trying to get it out (lots of attempts with various tools).

While assessing our options, we decided that the easiest solution was to fill from the bottom drain hole on the M46. A cheap $10 hand pump from Autozone was purchased and it included two 3-foot lengths of tubing that was just smaller than the inside diameter of the drain hole. I cut a 1.5"x1" donut from some foam pipe insulation, wrapped it around the end of the tube, and taped it tightly to the tube but only on the side facing the pump. This allowed us a soft push-fit seal over the transmission drain hole. I held the tube sealed to the transmission while my friend operated the pump. We attempted to overfill the transmission with an extra quart of ATF type-F, and with the amount we spilled and what was left in the tubing it worked out perfectly (or just a hair overfilled). FYI, the M46 should hold about 2.8 Quarts of ATF Type-F, and we attemped to put in about 3.5 quarts.

God bless and I hope you can get your fill plug out.
Fitz Fitzgerald.
--
'87 Blue 245, NA 239K

I would try some PBlaster, spray it for a couple days. Then apply some heat, and probably have to use a drift/punch/chisel to get it to turn. Since it's already chewed up, buy a new one.