So I'm somewhat in the process of swapping a FF rear axle into my '05 E350 eb---want the added weight capacity those offer. I'm fairly sure my donor axle's oil fill bung won't be an easy removal as I've already tried and it doesn't want to ease out. Wanting a way to refresh the lube and there's no easy way that's accomplished with the typical differential cover so I found one of these: https://www.rockridge4wd.com/search.html?q=yhcc-d60
That price is for a brand new in-the-box part and so far its priced far below any other seller I've found online or locally--FWIW most are asking $200 or more for the same part.
Jeg's one and only retail store is local to me and they were shocked to see such a low price, told me their cost was something like $163. (That's the lowest price they'll sell it for and still make a small profit---they probably buy it cheaper. Of course it would have to come from Yukon Gears as they don't stock them.)
I just received mine and its exactly what I expected. Do be advised it seems Yukon Gear is using Chinese or Taiwan parts these days but for this that shouldn't make too much of a difference. It does come with oil fill/drain plugs as well as hex-drive bolts/washers for mounting to the axle housing.
PLUS when I was talking with someone named Nick at RockRidge4WD he gave me a promo code that saved another $13.99. My final delivered cost was $125.96.
Anyway if you've ever thought to add something like this time's now. I don't know how these guys are selling that cheap but maybe strike quick before they smarten up?