So you don't have the time to work on your own differential? Who can you trust to do a good job? Whenever I take my truck to someone for repairs, I always cross my fingers, even if I know them. The automotive repair industry has a bad reputation for a reason, mostly because there are many unqualified or corrupt people in the industry. Now don't send me a bunch of letters defending the trade. I have made my living by doing repairs and selling parts for more than twenty years now, and I know that there are a lot of good people involved in auto and truck repair. However, identifying them can be difficult.
Finding a good diff repair shop can be harder than just finding someone who is honest and who truly cares about doing the job right. They must also be competent. When it comes to differentials, most mechanics, dealerships included, do not like to work on them. There are not many good manuals available, there are no really good training programs that I am aware of, and I have found differentials to be more of an art than a science. Unfortunately, this also leaves repair shops feeling frustrated in their search for a good diff mechanic.
When it comes to differential repair, I recommend trying to find someone at, or through, a four wheel drive shop. Four wheelers typically have more experience with diffs than speed shops or machine shops, although there are exceptions. Even if they do not do the work themselves, they can probably recommend someone who does.
Before having any work done, I always like to see the mechanic's work area. If the shop is clean, organized, and the personnel are proud to show it off, then I am somewhat more at ease. I also like to ask a lot of questions before I turn over my keys. Where do they get their parts from? Do they have them in stock? What kind of warranty comes with the parts and labor? How long will it take to do the job? How many diffs do they do each week?
One thing I always do is insist on getting an estimate for tear-down, inspection, and reassemble, in case I decide not to have the repairs done after receiving the estimate. Also, I always insist on an exact estimate for the repairs needed prior to them starting any actual repair work. Some states have excellent laws that protect the customer by requiring all repair facilities to provide these estimates, while some states provide no protection for the consumer at all. Finally, I recommend paying with a credit card. This not only insures that you have some recourse in the event of a problem with the shop, it also weeds out the shops that credit card companies will not do business with. One other thing I want to mention is that although I do not like to drive long distances just to have my truck worked on, I have found that the drive to a reputable shop is usually easier than the hassle of a bad repair experience.
Do I sound more than a little paranoid? Over the years, there have been many times that I have chosen not to work on my own trucks for one reason or another, and it has always made me uneasy to leave them with someone new. Fortunately, there are a lot of honest, competent repair facilities out there. Be aware though, they want your money as much as you do, and it never hurts to be cautious and ask a lot of questions. Simply taking time to investigate potential repair shops before any work is done will lower your chances of receiving a poor repair and increase your chances of receiving a fair deal.