Where in the heck is the fill hole / oil level check on a BA 10/5 tranny? And what kind of fluid does it take???

I just got a 1988 Cherokee ( manual tranny) and I'm trying to get every thing safety checked and ready for the road and the books I ordered are not here yet.

I saw a goofy sized square lookin plug ( not a 3/8ths ) on the passenger side on the tranny about have way up. Is that what I'm looking for??

 

might help: https://www.cherokeeforum.com/f2/how...-5-speed-6703/

 

Will this work for a 1988??

Its kind of hard to picture where the fill hole is on that picture. I'm still assuming its on the passenger side of the tranny about half way up??