Transmission and rear axle

Reference Details

Common issue

Later gearbox, rear end, floor shifter, or ratio represented as original equipment · 1955 Chevrolet Bel Air

Confidence

documented · 1955 Chevrolet Bel Air

Correct value

Case and axle stamps plus physical configuration consistent with three-speed/3.70, overdrive/4.11, or Powerglide/3.55 pairing · 1955 Chevrolet Bel Air

Where to check

Transmission case, differential carrier stamp, linkage, controls, and records · 1955 Chevrolet Bel Air

Common issue

Later automatic, floor shifter, nine-inch axle, or changed ratio represented as original · 1956 Chevrolet Bel Air

Confidence

documented · 1956 Chevrolet Bel Air

Correct value

Muncie/Saginaw/Cleveland case identification and AA/BA, AB/BB, or AC/BC axle stamp consistent with three-speed/3.70, Powerglide/3.55, or overdrive/4.11 · 1956 Chevrolet Bel Air

Where to check

Transmission case, differential carrier, linkage, controls, dates, and records · 1956 Chevrolet Bel Air

Common issue

Later four-speed, replacement transmission, or changed gearset presented as factory-installed · 1956 Chevrolet Corvette

Confidence

documented · 1956 Chevrolet Corvette

Correct value

Three-speed or Powerglide type, linkage, dates, and 3.55, 3.27, or documented 4.11 axle ratio coherent with the engine and history · 1956 Chevrolet Corvette

Where to check

Transmission case and date marks, shifter and linkage, axle housing and ratio evidence, and ownership records · 1956 Chevrolet Corvette

Common issue

Later four-speed, modern automatic, nine-inch axle, or added Positraction represented as original · 1957 Chevrolet Bel Air

Confidence

documented · 1957 Chevrolet Bel Air

Correct value

Transmission type, case, controls, axle assembly stamp, ratio, and Positraction equipment consistent with engine and factory application · 1957 Chevrolet Bel Air

Where to check

Transmission case, linkage, differential carrier, axle stamp, dates, and records · 1957 Chevrolet Bel Air

Common issue

Four-speed or Positraction hardware installed during restoration · 1957 Chevrolet Corvette

Confidence

documented · 1957 Chevrolet Corvette

Correct value

Transmission type and date plus differential type and ratio agree with the car's documented configuration · 1957 Chevrolet Corvette

Where to check

Transmission case and date marks, shifter/linkage, axle code/tag, housing, and order history · 1957 Chevrolet Corvette

Common issue

Replacement four-speed or changed axle represented as original · 1958 Chevrolet Corvette

Confidence

documented · 1958 Chevrolet Corvette

Correct value

Three-speed, four-speed, or Powerglide and conventional or Positraction axle ratio coherent with engine, dates, and history · 1958 Chevrolet Corvette

Where to check

Transmission case and dates, shifter, linkage, axle housing and ratio evidence, and records · 1958 Chevrolet Corvette

Common issue

Manual conversion, later automatic, changed ratio, or added limited-slip represented as delivered · 1958 Packard Hawk

Confidence

documented · 1958 Packard Hawk

Correct value

Flight-O-Matic with 3.31 axle or documented T85 manual-overdrive path with configuration-correct ratio; Twin-Traction only when supported · 1958 Packard Hawk

Where to check

Transmission case, controls, pedals, overdrive, axle housing and ratio, dates, and records · 1958 Packard Hawk

Common issue

PowerFlite, later automatic, manual conversion, changed ratio, or added Sure-Grip represented as delivered · 1959 DeSoto Adventurer

Confidence

documented · 1959 DeSoto Adventurer

Correct value

Standard three-speed TorqueFlite with 3.31 axle, or a fully documented special-order manual or optional ratio path · 1959 DeSoto Adventurer

Where to check

Transmission case and date, controls or pedals, linkage, axle housing, tooth count, Sure-Grip unit, and build records · 1959 DeSoto Adventurer

Common issue

Later four-speed, automatic conversion, nine-inch axle, or added limited slip represented as factory installed · 1968 Holden Monaro

Confidence

reported · 1968 Holden Monaro

Correct value

Engine- and model-appropriate three-speed, four-speed, or Powerglide controls with matching axle type, ratio, limited-slip status, dates, and records · 1968 Holden Monaro

Where to check

Transmission case, shifter, pedals, linkage, axle housing and ratio, body records, and service history · 1968 Holden Monaro

Common issue

Muncie, Turbo-Hydramatic, nine-inch, changed gears, or added limited slip represented as factory installed · 1969 Holden Monaro

Confidence

documented · 1969 Holden Monaro

Correct value

Engine- and model-appropriate manual or automatic controls with matching axle family, ratio, limited-slip status, dates, and records · 1969 Holden Monaro

Where to check

Transmission case, shifter, pedals, linkage, axle housing, ratio, plates, and history · 1969 Holden Monaro

Common issue

Muncie, Turbo-Hydramatic, nine-inch, changed gears, or added limited slip represented as factory installed · 1970 Holden Monaro

Confidence

documented · 1970 Holden Monaro

Correct value

Engine- and model-appropriate manual, Trimatic, or GTS 350 Powerglide controls with matching axle family, ratio, limited-slip status, dates, and records · 1970 Holden Monaro

Where to check

Transmission case, shifter, pedals, linkage, axle housing, ratio, plates, and history · 1970 Holden Monaro

Common issue

Later gearbox, nine-inch axle, changed gears, or added limited slip represented as factory installed · 1971 Holden Monaro

Confidence

documented · 1971 Holden Monaro

Correct value

Engine- and model-appropriate M15, M20/M21, MC7, M40, or M41 with matching banjo or Salisbury axle, ratio, limited-slip state, controls, and dates · 1971 Holden Monaro

Where to check

Case, shifter, pedals, linkage, axle housing, ratio, plates, dates, and records · 1971 Holden Monaro