1986 select trac t-case

[jj rich]

on my 86 xj, there is a hole in the top rear right side of my t-case. im not sure what it is but the drive shaft clicks everytime it rotates and im not sure if its a vent or overflow or if a bolt may have went there and has fallen in the t-case. the t-case is a 228-a
any ideas???????
jj rich

[rixXJphx]

My Chilton's shows a nipple at that location for the vent. I *think* there was supposed to be a vent hose coming off the nipple.

Take a photo if you can, and go to a Jeep stealership for a new nipple.