TRANSMSSION DETAILS: TREMEC T45

The T45 five-speed overdrive transmission was developed primarily for high-performance cars with relatively high-engine torque requirements but is adaptable to other light-duty applications such as sport-utility light trucks.

Product Run
1996 – Feb 2001 Ford 4.6L Mustang

The Borg-Warner T45 was introduced in 1996 when the Ford 4.6L Modular motor was released.  These transmissions were only used behind 4.6L single and dual overhead Mustangs from 1996 to 2001.  TREMEC, in 2001, replaced the T45 with the TR3650 which is very similar in design.  Added strength comes from a 31-spline main shaft and front-loading case.  The T45’s design is very much like the T56 six-speed transmissions.  In fact, the T45 and T56 share many of the same parts.  It has a single rail gear selector and carbon-lined steel synchro rings making it a smooth shifting transmission at high rpm’s.  The gears are larger and stronger than a T5.

T45’s from 1996-98 GT are different than the Cobra Mustangs
– the GT’s received an 8-tooth drive speedometer drive gear.
– The Cobra Models had a 7 tooth speedo drive gear as well as the transmission mount point, which was moved farther back.

The 1999 – 2001 Cobras & Mustang GT’s T45’s were all equipped with a 7-tooth speedo gear or reluctor wheel for VSS electronic speedo.
Moving forward all T45’s receive a 7 tooth speedo gear or reluctor for VSS.
Why this was not done earlier is not understood.

T45 shifters are the same as the T5 shifter, therefore, any aftermarket shifter will work on both transmissions.
Borg Warner WC T5/T45/T56 all use ATF oil or Synthetic ATF.  No other oil should be used.  Redline MTL should not be used.  Redline ATF is fine.
MDL’s recommendation is to use Amsoil ATF as we have used it for years at the track with great results.

Features & Benefits:

• Center Distance – 81.5 mm
• Overdrive in fifth gear provides extended ratio coverage
• Integral clutch housing with front cover end-loading design for increased driveline bending strength
• Clutch cable release fork pivot
• Tapered roller bearings on main and countershafts reduce noise and improve durability
• Needle bearing under 1st through 4th gears improve high speed performance and reduce shift effort
• Advanced synchronizer technology:
  • Powdered steel formed blocker rings
  • Engineered friction material for improved durability
  • Double cone synchronizer design for lower shift effort in first and second speed gears
  • Patented strut-type synchronizer design for improved durability
• Constant mesh, double disconnect reverse
• Internal, single rail shift system
• 10-spline input shaft, 31-spline output shaft
• Torque Capacity 400ft/lbs