Checking BTR diff oil level

[Leckypete]

Hi all,
I took my car round to in laws house armed with toolkit to use pit to check the diff oil level, have 1st edition of the bible and sure it showed a level plug at back of diff with square 3/16 wrench hole but when I got underneath the only thing that looked like a level was a large hex nut (had a tag held on with it) about 21mm? Didn't have any big scanners so didn't even try it but looks tight against chassis for access! On drivers side of diff.
Couldn't see anything on back, was a flat section about where was expecting to see plug but only fixing bolts around outside.
No drain plug to be seen?
Has BTR industries cast into it.

[kris450]

If it is a BTR diff then the drain plug is the very most lower central bolt on the back plate. In the below photo its in line with the raised lettering at the very bottom.

To check the level its the large plug/blot on the offside just in front of the drive shaft. And yes, access isn't great.



Hope that helps

[Leckypete]

Thanks Kris that's just what I needed.
Looks like will have to take big spanner round next time!
Do you know what size it is?

[kris450]

I'm not 100%, but I'm sure its either 27 or 29mm (leaning towards 27mm). Decent size adjustable spanner is what you'll need as there isn't room to get a normal socket and ratchet/bar in there.