The OD in the '83 240, which I was fixing up for my daughter, would not stay in overdrive unless I held the gearshift lever hard down and to the right. This indicated a bad 4th gear switch on the transmission. All the manuals say to put a jack under the tranny, remove the bolts on the cross member where the tranny mounts, and lower the tranny to get room to put a crowsfoot wrench on the 4th gear switch (top of tranny). Some others have had luck with sockets and swivel joints. The switch takes a 7/8" socket. My regular sockets were too shallow and my deep sockets too long (no room for the ratchet on the socket).

So here's how I did it. I found that my oxygen sensor deep socket, the type with a slot in the side for the sensor wire, was a 7/8". Not only would it slip on the switch but the end of the sensor socket had a hex shape which would take a 1" open end wrench. I put the socket on the old switch, gave about a 1/3 turn with the 1" wrench and the switch came out the rest of the way with just my fingers. Reversed this to put the new switch in. Took about 10 minutes for the job once I realized the sensor socket would work. If you have this sensor socket remember it may work for this job too.

Oh yes, the OD now works just fine.