The reamer in tool kit F-126740-TL6 requires the use of a reamer stop for this application. Sonnax includes the reamer stop in newer tool kits for this application. However, if you own an older tool kit Sonnax recommends using McMaster-Carr 98381A619 or another of the same dimensions.
Ford 6R140 transmissions may exhibit multiple shift problems due to excessive wear in the solenoid modulator circuit. Flare and harsh shifts as well as a delayed Forward and Reverse are common results of the wear. Reconditioning the bore and installing Sonnax oversized solenoid feed pressure regulator valve 126740-24 restores hydraulic integrity for a properly modulated solenoid pressure.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.