Can anyone identify the hole in this photo, and what is supposed to go there? My son found it changing his oil, but the hole appears to be part of the transmission. It appears to be threaded on the inside but not sure on that. Nothing was there when he went to change the oil. Any thoughts? Any help is appreciated.
I believe it's just a hole. It is open to the bell housing. I think it gives an escape route for any oil/debris which might otherwise accumulate.– Pᴀᴜʟsᴛᴇʀ2 ♦May 20, 2017 at 23:54
it is better to find something missing than something "extra" like I frequently do :) sorry for not answering your question.– AusMay 21, 2017 at 19:51
Bell housings do normally have holes in them. If this is on the bottom area it is nothing to be concerned about, unless you drive through deep water for significant periods of time then you should plug it during those times. It's not common to remove the transmission though when changing the oil.
That transmission looks very similar to the one in my 92 C1500. Mine has a plug covering the hole. I can't find any reference in the manuals as to its purpose. The clutch slave cylinder is mounted to the front of the bell housing in this area. I'm guessing it is or was for accessing the clutch release mechanism, for lubrication perhaps.