This post is just a heads up for owners of 2011-12 Ford Mustangs who are having some cold shifting problems with their MT82 6-speed manual transmissions. Ford has addressed the situation by issuing a Technical Service Bulletin (TSB) to owners of 2011-12 Mustangs. Basically owners are experiencing increased shift efforts in cold temperatures. As an owner of 2011 Mustang with a six-speed I can attest to this. When the weather was cold here in Texas I had issues getting the car in gear at times but after the car warmed up there were no issues.
The fix is to replace the Motorcraft full synthetic manual transmission fluid currently in the car with Motorcraft Dual Clutch transmission fluid. The new fluid is suitable for use in all ambient temperatures and seasons. For the complete TSB check below.
TSB 11-3-18, 2011-2012 Ford Mustang:
Some 2011-2012 Mustang vehicles equipped with a MT82 6-speed manual transmission may exhibit increased shift efforts in cold ambient temperatures. This is usually most noticeable in 1st and 2nd gears but may also be noticed in 3rd through 6th gears. The increased shift effort may be the result of the increased viscosity of the transmission fluid in cold weather.
Follow the Service Procedure to correct the condition.
Replace the Motorcraft Full Synthetic Manual Transmission Fluid with 2.6L (2.7 qt) of Motorcraft Dual Clutch Transmission Fluid. Refer to Workshop Manual, Section 308-03A for the transmission fluid draining and filling procedure. This fluid is suitable for use in all ambient temperatures and seasons, and the Scheduled Maintenance guidelines in the Owner Guide can continue to be followed. The use of friction modifiers or other fluid additives is not recommended since although they may provide some immediate improvement in cold shift effort, they are likely to result in long term degradation of the synchronizers.