That's what I suspected. There is very little clearance to get any tools in there to remove the retainer and o-ring.
Anybody else had any luck removing the shift shaft o-ring on an NP231 without opening the case?
In addition, if I remove the case and open it up, does anyone have any recommendations of things to do while it is out of the truck? Obviously front and rear output seals, input seal, shift shaft seal. Anything else? Beneficial modifications to do while it is off? It already has an SYE.
Thanks everyone, I appreciate your input in advance.
Aaron