I’ve seen Teague drilll and set screw the case to hold the retainer nut from backing off, it looks like it broken in this area

When facing the input shaft Teague puts the set screw at 1:00.

Looks like that is what was there in the pic

Oh, yes, you can see the hole where the set screw was at the edge of the break. Maybe someone didn't know about the set-screw and they beat the crap out of the spanner nut trying to get it loose until the case broke.
https://cimg2.ibsrv.net/gimg/www.off...51da4cdaf7.png

That drive looks like it was taken apart MANY times.

Didn't know Teague did that, but if they did that to my drive (Put a set screw in) I could hear me doing my Ricky Recardo impression, somebody got some splain to do

You guys nailed it.

Looks like the housing was drilled and tapped for a set screw. (he mentioned Teague does do this) It does appear as someone tried removing the spanner nut without removing the set screw and cracked the aluminum because of it.

Talked to the seller again today and he is going to meet me for a full refund of my $$.

Bad part is, I got to drive another 4 hour round trip to do so. :(

Gas is cheap. Glad to hear the seller is doing the right thing.

Got my $$ back today.

Thanks for the replies guys.

Seller spoke to his mechanic who said the chunk missing was fine. The seal is about 1" further inside the housing. offered to buy it from the seller for more than i bought it for. That's prob why he gave my $$ back, but it all worked out in the end I suppose.

My first thought as well.