Dana 20 Question

[Duck]

I recently purchased a 76 CJ5 with 6cyl,3spd tran,Dana 20 transfer. While draining and replacing fluids in the Transmission and transfer (many threads on this site were very helpful, thank you All!!) I became a little confused about which is the fill plug on the Transfer Case . When I look up from behind the skid plate I see (on the drivers side) a bolt that appears to be a plug but is 6 sided. On the passenger side back of the case I see a square plug. My Haynes manual is unclear which is which. The 6 sided "plug" seems to be higher up so I could get more oil in, but I don't want to over fill. This is my first Jeep and my first post, any help would be appreciated.

 

[BusaDave9]

Dana 20s have had the fill plugs in 2 different locations. Sometimes it is on the side of the TCase. Sometimes it's on the back. I have had 2 Dana 20s and the fill plugs were different on each.
These 2 red circles show the 2 locations.

Fill the TCase until the oil is up to the fill hole.

 

[Duck]

Thank you, however, the second hole with the 6 sided bolt/plug I was referring to is on the opposite end or side of where your two red circles are, adjacent to the yoke for the u joint. Is this something different? Supposed to be a breather or something else?

 

[mtnwhlr]

All the fill plugs I have seen are 4 sided that is the one I would use.

 

[Duck]

Here is a picture of what I am talking about. The bolt is threaded partially into the hold at the top left of the Transfer Case . Photo is taken from the rear of the vehicle on the drivers side.

 

[7D8CJ]

Here is a picture of what I am talking about. The bolt is threaded partially into the hold at the top left of the transfer case. Photo is taken from the rear of the vehicle on the drivers side.

That is NOT the fill plug.

 

[Duck]

Any ideas as to what it is?

 

[7D8CJ]

Had mine apart 5yrs ago. Don't remember what it's for. Chek out this link though.
Pirate4x4.Com - Extreme Four Wheel Drive

 

[CJim7]

There's a breather on that housing...but that doesn't look correct