Ford Repair: 03 GT 8.8 Rear End Woes, excessive friction, rear gears

Question
Hi, Need some expert advice. I have an 03 Centennial GT Convert, 59K Miles bought used in May. Had some small barely audible clunking noises in rear end once about every revolution of the rear wheels. I took to a mechanic who I had used to rebuild my 302 in my 68 stang conv. I decided to also change our gears to 3:73 ford motorsport. He tore it down, put in new gears then reassembled. Terrible howling experienced immediately. Tore down again, replaced all bearings, axles, clutch plates. Put back together still howling. Brought in a body man who said housing was bent. There was evidence car had taken a lick to the left side. I purchased a used rear axle housing (complete) out of a 99 GT. He tore it down and put all my new parts in, still howling but now mostly when there is no pressure on the rear gears (coasting). I don't want to give him any more opportunities because he either is inexperienced with rear ends, or there is something else wrong. I did learn he doesn't own any dial gauges which I understand are needed to check lash? What do you suggest I do. I have been driving it and tolerating the howling noise but it must be doing harm to the new gears.

Answer
Don-

  The howling is most likely caused by excessive friction.  My guess is the guy didn't set the pinion depth properly.  Depending on how long you've been driving with the gears howling they could still be useable, but I'd have someone else adjust the gears.  Even if the guy you've been using knows his stuff, this is one of those jobs that absolutely requires the right tools to get it done properly.  Hope this helps.

Steve