Rear Diff Issue

[FordFreak]

First off let me apologize for the length of this post. I need some re-assurance on this issue. I had my '99 F-150 Re-geared to 4.56 a little over 3 years ago now. I have 35" tires, so I went to the new gears. I went to a reputable shop (I will not name where) to have them installed. I was happy with the price and work. It was recommended that I change my fluid in the diff in another 2k mile or so. I did so without any problems. 11 months (and 9k miles) later my ABS light came on and I noticed a leak in the rear diff with dents all over the cover. I took it back to the place that installed my gears and after new bearings, posi, and ABS sensor I was told that a ring gear bolt had broken and caused the problem. This past week while driving I noticed a couple of kachunks coming from the rear of the truck. I took a look at the diff and saw what looked to be dents. I just changed the fluids and when I opend the diff I found what looked like to be a backed out ring gear bolt. What are the chances of this happenening? I assume that is is highly unlikely. This made me think that the first problem I had may not have just been a fluke thing. I don't really want to go back to the shop and have them make sure everything in the rear is ok. What should I do?

[matt_helton]

red locktite!!

[ASITool]

Had a similar situation changing ratios -- different ring gears requiring different diameter bolts. Shop used old bolts which were too small and eventually sheared.

[14802]

I had a fairly decent shop(I thought) do a R&P swap on a old suburban I had. The shop called to tell me that 2 of the bolts were sheared off in the carrier. So I went down to the so called "shop" and found out that the numb-nuts(impact gun still in hand)did not know about the left-hand threads...
If for some reason the shop you took it to forgot the direction..It might have stretched the bolt for a latter failure???

[sickrick]

red locktite!!

Red locktite.