I think it's like RUSSGT mentioned, cheap replacement hubs are to blame.
Either that or someone swapped in one from a different year range or manufacturer or ... who knows. I don't even know if it's possible but these Dana 44 setups are on a lot of makes.
I found a Wagner replacement hub from Jegs:
http://www.jegs.com/i/Wagner/436/BD61708/10002/-1
Does anyone have any experience with these?
Thanks,
Lawrence F.