Replacing the oil sending unit

[spot]

Has anyone replaced/removed the oil sending unit on a 2.9 while everything was still assembled? Simple as replacing a spark plug but how the hell do you get a tool around it to get the old one out?

[1highlander]

I had to do that on my 88. There are two different sending units (depending on year - both work): one is about an inch thick from where the threaded part leaves the body to where the terminal end comes out. The other is about twice that big. Both use the same socket. But with the longer one you need the brass extension between the block and the sender. It is available. Or you can use the smaller unit without the extender. As for getting the old one off, if it is the bigger unit and no extender, you will end up using an open-end (I think it's a 19mm or a pair of slip-lock pliers (since you are going to trash the part anyway). Then you can use an appropriate deep socket to install the new one. At least that is what I had to do. If you don't have the extension, it doesn't matter if you are using the shorter sender.