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