I have had 2 experiences with thief mechanics----once years ago wife visits friend at Ft Bragg, NC. Gets ready to come home and gas station guy tells her the Mercedes trans needs help. They pulled the trans before she called me. I told her to get on a plane, sent a roll back after it, we put the trans back in and that car is still running around here 30 years later. Same deal with 16 year old daughter with my NEW Ford F-350 with Horse trailer stops near Columbus Ohio for fuel and is told trans is leaking, SHE crawls under truck, sees nothing, call home and I tell her to continue. Drove that truck for 7 years with no transmission trouble. The thieves are out there and $21,000 is about 3 times what you should be paying.