240 speedo sender (diff leak)

My differential leak has finally gotten to the point that I *need* to do
something about it, so a couple of questions:

Does anyone have any tips or tricks for removing the speedo sender in a
'90 240? Also, does it have a seal or o-ring somewhere in there, or am
I looking at something more involved?

thanks
-erik

 

The nut on the back of the sender unscrews. Use channel locks to undo.
There is an O-ring seal on the sender.

Bob

 

Thanks! Any clue as to the size of the o-ring? None of the places around
here list the specific part, but anyone can get an o-ring...

-erik

"volvowrench