I have a 2001 4 runner, need to change the grease fittings, found the middle one with 7mm can be take out, but not the two sides one.
tried 6mm nothing doing. Any ideas ?

What is the problem? Won't the socket fit or won't the fitting give? or what?

socket won't fit, I should have stated that sorry.
Not with 7mm nor 6mm, the others fit right with
7mm socket.

Try 1/4" or 3/16" or whatever. I think they may be English, not metric.