Mister Transmission

My SUV was having an issue when I would brake hard and come to a stop and then hit the gas afterwards. It would slip like it was in neutral and then go back in gear after I let off the gas. I took it to Mr Transmission as they are just down the street from my house, are a national chain and specialize in transmissions. They inspected it and told me it was likely a rubber seal on a valve that needed replacing. The part was inexpensive but they needed to pull the tranny to change the seal. They quoted me over the phone at $1300~ taxed in. A few days later they called and said it was all done and working well, and the final bill was $1500~. I told the guy I was quoted 1300 something and he got mad and said he would speak to the boss but nothing was going to change, dismissing me. The boss called a while later and apologized and said he forgot to tell me about some extra part he replaced. He offered to honour the original quote, I suggested we split the difference and settle at $1400~. I drove the suv to work and within minutes it was doing the same problem. I called the boss and asked wtf. He acted surprised and sorry. I asked what he could do now, he said he didn't know but they could open it back up and look again for something wrong. I asked if that would cost another $1400 and he said "of course". I was in shock that I just spent $1400 on nothing. He told me he would do some research that night and see if there was any other known issues. I said I would wait for his call. Six months later, never any call from them. I ended up figuring out what it was, a bushing on the shift linkage was worn and the gear would not lock into drive and slip into neutral. I fixed the problem with a $15 part and took only 30 mins. The kicker is that they definitely would have removed the linkage while dropping the transmission and hooked it back up with an obviously worn out bushing. These are transmission experts. My only conclusion is that they are either totally incompetent or just thieves. Either one is unacceptable. I would stay away from this shop.