Toyota Motor Corporation's K family is a series of 4 and 5-speed light/medium-duty transmissions found in Toyota Corollas and Starlets.

K40

Oil capacity: 3.0 imp pints(1.7L)

Synchromesh on all Forward gears

Ratios:

• First Gear: 3.769:1
• Second Gear: 2.250:1
• Third Gear: 1.405:1
• Fourth Gear: 1.010:1
• Reverse Gear: 4.316:1

Applications:

• Most 4-speed RWD Starlets and Corollas with K-series engines
• KM20 series LiteAces that were fitted with K-series engines had a standard K40 fitted with a column shifter
• Toyota Racing Development** has produced a fourth gear closer to third in Ratio

K50/K51

Oil capacity:4.2 Imp pints(2.45L)

Synchromesh on all Forward Gears

Ratios (K50):

• First Gear: 3.789:1
• Second Gear: 2.220:1
• Third Gear: 1.435:1
• Fourth Gear: 1.000:1
• Fifth Gear: 0.865:1
• Reverse gear: 4.316:1

or (K51)

• First Gear: 3.789:1
• Second Gear: 2.124:1
• Third Gear: 1.323:1
• Fourth Gear: 1.000:1
• Fifth Gear: 0.865:1
• Reverse gear: 4.316:1

or

TRD GEAR SETS TRD also sold a close ratio gear sets in the 70's and 80's (P/N 33030-KP601) for the K-50 with the following ratio:

• 1st: 2.695
• 2nd: 1.619
• 3rd: 1.235
• 4th: 1.000
• 5th: 0.892

Applications:

• Most 5-speed RWD Starlets and Corollas with K-series engines.
• 1986 Corolla with 3A-U and 4A-U engines.
• KM20 series LiteAces were fitted with K50 transmissions to 4K and 5K engines as an option, and to the 7K as standard.