Yep make sure it's got the axles in, a 3.08 is common as dog's balls and I doubt they'd take them apart anyway.
Basically, hold the wheels still and wiggle the tailshaft yoke - you'll probably get a little play, but if it moves more than a few mm before engaging the gears, it's getting a bit flogged out.
Also try to move the axles inside the casing - if they move, the bearings are severely bad
Other than that, just stick your finger in through the filler hole and see if you can find any dirty crap or metal filings inside the casing.
the EA/EB/ED 3.08 is exactly the same unit...
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