BorgWarner T-5 transmission

The BorgWarner T-5 is a 5-speed manual transmission for longitudinal engine automobiles. It includes one overdrive gear, a lightweight aluminum housing, and adaptability for four wheel drive use.

It is currently manufactured by TREMEC.^{[clarification needed]}

The T-5 was originally designed by BorgWarner based on the T-4 and earlier SR4, and was sold as the BorgWarner T-5 until the design was sold to TTC (aka Tremec) in the late 1990s.^[1] The SR4 was a light-duty 4-speed manual that used ball and needle bearings on the countershaft with bronze synchronizer rings. The T4 improved this design with tapered roller bearings on the input and output shafts and a straight roller bearing on the counter gear. The T-5 is a T4 with an added overdrive gear.^[2] The T-5 carries a part number of 1352-000-xxx, where xxx is a three-digit application-specific number ranging from 001 to 260 that also can be used to distinguish World Class from Standard T-5 transmissions.^{[3]: Tables 3-1 & 4-1}

The first T-5s were installed in the AMC Spirit/Concord. In 1982, GM began fitting the T-5 to the S-10/S-15 compact pickup trucks; then in 1983, both Ford (Mustang) and GM (Camaro/Firebird) picked up the T-5 for their pony cars.^[4]

The T-5 has become a popular restomod option for older and classic manual transmission cars, as the overdrive gear can improve fuel economy.^[5] In general, retrofitting the T-5 is straightforward for many rear-drive Fords from the 1960s and 1970s, as they are dimensionally compatible.^[6]

The T-5 is available in "World Class" (WC) and "Standard" (STD) models; STD are sometimes known as Non-World Class (NWC). Compared to the Standard, the WC changes bearing types and blocker ring materials.^[3] Externally, the tapered roller bearing race for the countershaft at the front of the WC, facing the clutch and below the input shaft, can be distinguished from the corresponding straight roller bearing cup of the STD.^[1] If this is not visually accessible, the color of the synchronizer rings can be used to distinguish the two types, with the oil fill plug removed.^[2] WC transmissions should be filled with automatic transmission fluid, while STD models use 50W gear oil.^[1]

STD transmissions are rated at up to 265 lb⋅ft (359 N⋅m) of input torque with a 2.95:1 first gear. Most STD transmissions have a first gear of 3.75 to 4.10:1 for smaller-displacement engines; these so-called 4-cylinder T-5s are rated up to 240 lb⋅ft (330 N⋅m) of input torque.^[4]

WC transmissions initially carried the same maximum input torque rating of 265 lb⋅ft (359 N⋅m) until hardened first gears were introduced in approximately 1990, raising the rating to 300 lb⋅ft (410 N⋅m). Typical first gear ratios for the WC ranged from 3.35 to 3.97:1; the Ford Mustang SVO had a unique 3.50:1 first gear for 1986.^[4]

• "T-5 5-Speed Rear-Wheel Drive Manual Transmission". Tremec.
• "Identifying a T5 5 Speed". 5speeds.com.