Porsche 901 transmission: types, years and gear codes explained
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- PorschePrototype.com Editors
- Filed
- Sources checked
- 3 listed below
This record covers
- What the Porsche 901 transmission is
- Which cars and years used it
- How to read 901 and 902 type numbers and gear letters
- Why a 901 gearbox is not a prototype part
Short answerThe Porsche 901 transmission is the manual transaxle Porsche designed for the 911 and 912, used from 1965 to 1971. It has a dogleg first gear and Porsche synchromesh, and came in four- and five-speed versions. Six-cylinder cars used 901-series type numbers and four-cylinder 912s used 902-series numbers. From 1970 Porsche moved to pressure-cast cases and 911-series type numbers. A gearbox stamped 901 is an ordinary early 911 or 912 part.
- Used in
- 911 and 912, 1965–1971documented
- Shift pattern
- Dogleg firstdocumented
- 912 gearboxes
- 902 seriesdocumented
- “901 means prototype”
- Incorrectclaimed
People searching for “Porsche 901” often want the gearbox, not the car. The 901 transmission carried the car’s original type number for years after the car was renamed, which is also why it turns up in prototype claims.
What is the Porsche 901 transmission?
The Porsche 901 transmission is the manual transaxle developed with the 901 project: gearbox and differential in one housing, mounted behind the engine. It uses Porsche’s own synchromesh and a “dogleg” pattern, with first gear to the left and back, so second to third and fourth to fifth sit on straight lines.
Which years and cars used the 901 transmission?
| Type | Application | Years |
|---|---|---|
| 901/00 | 911 | 1964–65 |
| 901/02, 901/03 | 911 standard | 1966–68 |
| 902/1, 902/02 | 912 | 1965–69 |
| 901/51–54, 901/76–79, 901/81–84 | Competition variants (hillclimb, airfield, fast track, Nürburgring) with 904 mainshaft | 1960s |
| 911/01 and later 911-series | 911 | From 1970 |
Early cases were sand-cast aluminium; later cases were magnesium. From 1970 Porsche used pressure-cast cases and a pull-type clutch, and the type numbers moved to the 911 series. The later 915 gearbox arrived with the 1972 model year.
How do you read 901 gear codes?
You read 901 gear codes from left to right: type number, then one letter per gear ratio, then the ring and pinion. A code such as “902/0 A F M X S 7:31” names the gearbox type, the ratio letters for first to fifth gear, and a 7:31 final drive. Each letter stands for a specific ratio; for first gear the range ran from 3.091 (A) to 2.400 (C). The letters tell a restorer which ratios the box was built with, not which car it came from.
Why is a 901 gearbox not a prototype part?
A 901 gearbox is not a prototype part because 901 was simply the internal type number of production 911 components. Thousands of production 911s and 912s left the factory with 901 and 902 gearboxes. Finding one in a later car shows a period part was fitted, nothing more; the same logic applies to early engine parts discussed in the $21 million “911 T prototype” case file.
How do you confirm the gearbox is original to a car?
You confirm the gearbox is original by comparing its stamped number and type to the factory record. The Porsche Classic Technical Certificate records engine and transmission numbers and checks them against original records; the Production Specification does not. The difference is explained in the Porsche Certificate of Authenticity guide. Engine numbers follow their own system, covered in the Porsche engine numbers guide.
Frequently asked questions
What cars use the Porsche 901 transmission?
The 901 transmission was used in the Porsche 911 and, in 902-series form, the 912 from 1965 until about 1971, and variants appeared in the 914/6. The 904 racer’s mainshaft was used in some competition versions.
What does 901/02 mean on a Porsche gearbox?
901/02 is the transmission type number: 901 for the gearbox family and 02 for the version. It is followed on the case by letters for each gear ratio and a figure for the ring and pinion.
Is a Porsche 901 gearbox valuable?
Correct original 901 gearboxes are sought by owners restoring early 911s to matching-numbers condition, which supports prices for complete units, but a 901 gearbox is a production part, not a prototype component.