04 Columbia Par Car Differential Question

[kv1370]

Hi,
I have a 2004 Columbia Par Car and wanted to check the level in the differential. I don't have a service manual for this year, but do have one for 1996-2000. In that manual, it shows a fill plug, a check plug, and a drain plug, located at different heights (but all on the side of the differential). My differential has a fill plug located directly on top of the differential and a drain plug on the side at the bottom. I can't find a fill plug though. There is an indentation at about the height a fill plug might be, but there are no threads in the hole and I stuck an ice pick in it and it doesn't go through to the inside of the differential. How do I know if the oil level is good? When I look through the filler hole, the oil is covering all but about 1/4" of the gears.
Thanks

[Lochlin]

The one on top should be the fill plug and it should be threaded. Not sure why the manual is mentioning a 3rd hole.

Don't kill yourself worrying about the proper fill level. Definitely better to have too much gear oil rather than not enough. I fill mine to about an inch of the top. My camp neighbor fills his all the way to the top. Not sure what harm too much can cause but maybe someone else will chime in if they know something I don't (which is very possible).

[kv1370]

The one on the top is a rubber plug that pops into a fairly large hole (over an inch in diameter). I thought if you put too much oil in them, you could damage the differential.