Trans was done about 7 years ago by PTS and has held up awsome I have gone mid 10,s for years with it ,I have no idea what boost valve or spring was used. This problem has been on and off for years now ,I have tried the tv adjustment and no change. I have to put the trans in nuetral when I come to a stop and then back to D to make sure it goes into first when I take off . sometimes it will downshift on its own ???