Hyundai Repair: 2001 Santa Fe transmission, transmission repair shop, design updates

Question
First let me thank you for answering my last question.  It was most helpful and according to my diagnosis the transmission on my Santa Fe is shot.  I'll need to either rebuild the transmission or replace it. The transmission repair shop wants $1700.00 to rebuild it.  I wonder what would prevent me from accomplishing this myself?  I am not a mechanic but I have worked on cars before.  I have noticed throughout the years I've owned this vehicle that the car was designed and built more or less in a "plug and play" fashion.  I've noticed how easy some major issues can be readily solved once you know the puzzle of how a particular piece was installed.  I know rebuilding the transmission at home would be a major task requiring considerable amount of homework and preparation.  But is it an impossible task such does it require the use of a high end tool that only a transmission shop would have access to?  Or any other issue.

Answer
I've not heard many stories about professional rebuilds on these transmissions that were successful.  I typically don't even consider rebuilding an automatic because Hyundai prefers us to replace the transmissions.  So, I'm not particularly recommending a non-expert attempting a rebuild on this transmission.  To do the job properly, you'll need to completely disassemble the transmission, carefully inspect all the parts of the transmission for abnormal wear (and replace any that are needed), thoroughly clean the valve body, and replace the clutches, seals, and gaskets.  I don't recall the specific problems you had with your transmission (and they aren't referenced here since this isn't a follow-up attached to the previous question), but you may also need to evaluate some of the electrical components as well.

If you're able, replacing the transmission with a factory remanufactured unit is probably a much better choice.  Typical cost from a dealer would be in the $1000-$1100 range.  Furthermore, any design updates to improve reliability will be automatically done to this unit.  But it's even doubtful that you'll be able to do this.  You'll need to remove the subframe from under the engine and transmission (requiring engine support) to remove the transmission.  In addition, if it's four wheel drive, you'll need to remove the transfer case as well.  Depending on what you're considering, I'd recommend calling your local dealer and obtaining a price on the transmission as well as installation.  If it's close to what you'd pay for the rebuild, it's pretty much a no-brainer to go with the factory remanufactured unit.