My local mechanic found that the diffy fluid was about 1 qt. low when he checked out the noise problem. There is no doubt in my mind they didn't put enough diffy fluid back in when completing the install.

I am assuming this statement is correct. IN GENERAL I think someone would notice losing a quart out of the diff via a puddle in the driveway. (Before we go technical and drag away the main point, no I don't think it dumped a full qt at once in the driveway, but that you would notice some drips and would investigate).

Do I know everything that was involved? No. But neither does anyone else who replied. So, given the following:
1. The facts we have û a vehicle damaged and a differential a quart low.
2. An assumption that the owner was reasonably intelligentùie. if they saw any drips on it or the driveway and would check it out.
3. An assumption the mechanic was reasonably intelligent and looked for some tell-tale signs of a six month leakà..like moist oil, or caked oil and dirt instead of a clean diff.
4. And the remote possibility that the diff was filled but not enough to clear a "bubble" out of the system...say if the SUV was leaning on the lift
5. We can reasonably assume that most differentials, when sealed, hold their fluid pretty well and don't need to be checked every month (Your rig may--and from your comment seems to--vary..... <img src="/forums/images/graemlins/wink.gif" alt="" /> but I only check mine every 30k)

It is not certain that the shop messed up, but there is the possibility. By the rules of the board, this person posted his personal story.

Or let me phrase it your wayùif you pay Jiff-Wal-Lube to change your oil, your statement says they are only responsible to drain the oil and replace the filter. It's up to you to verify they put new oil in there. If you don't catch it until you drive home or a week later (if it was a few quarts low) and the engine seizes, it's your fault and your problemùdeal with it. <img src="/forums/images/graemlins/shame.gif" alt="" />

I think our difference is I'm assuming the owner and mechanic are honest and reasonably intelligent, and that a shop might, just might make a minor mistake. I know, it's never happened before in the history or auto maintenance, but do humor me that it might occur (sarcasm alert)

And I've seen moderator posts that were blunt and not rude. *My opinion*, the above was again outside the normal "blunt" lines and general good courtesy I usually see here.

This is not meant to be an all-out CAPS argument, I just wanted to highlight the point of disagreement that I believe was missed.

Wayne