Hello All, Thank you very much in advance for the help. Last week I purchased the vehicle from a junk yard after they purchased it at auction. It has 107,000 miles. The yard owner was very up front and said he thought there was a transmission problem base on his driving it about 4 months earlier. He hadn't driven it since until we test drove it. During our test drive it ran fine, no codes, no shifting issues, felt great. I then went to pick it up on Saturday and after a mile or so the check engine light came on. At low speeds it felt ok but lacked power when starting from stop. At higher speeds it felt not great. At 45mph when I took my foot off the gas the transmission seemed to disengage abruptly. And it was sort of hard going back in when I stepped on the gas. I'm new to this vehicle so it was hard to determine which gear I was in. On the highway I got up to 55mph and apart from the issue just described it seemed ok, tac was not abnormally high, I think around 2000-2500. No tranny noise and fluid was nice cranberry red. I brought to my mechanic who is generally good and whom I trust. He called today to report two error codes P0740 and P0758. He said he had a similar problem with a Blazer he owned and had to replace the tranny. Being ignorant but also after asking the basics questions like: can't you just replace the shift solenoid, I agreed to approve him to proceed with the transmission re-build at $2k. After doing some research on the two codes it would seem a lot more trouble shooting is needed before we replace the tranny. I am going first thing in the morning to find out what other troubleshooting he did. That being said, is it common for this vehicle to need a new transmission after 100k miles? How likely is the problem a transmission failure versus the numerous other electronic/wiring issues I've read about. Again, thank you very much for the help.