What we do for the 904 gearbox
Gearbox shafts with slip-fit 2nd gear
the well-known 904 peculiarity, as a dimensionally faithful new production in high-strength steel.Nadella stub axles
newly made, ground and heat-treated — the originals have been unavailable for decades.ZF-based limited-slip differential
homologation-ready for building historic racing gearboxes, locking value to regulations and use — uprated version with Nadella flanges in stock.Gearbox housing with steel insert
the 904 housing with cast-in steel bearing insert as a new production, in stock.Fittings from stock
gearbox mount, spring-loaded reverse lock-out as used by Porsche Motorsport, release lever, shift finger with bracket, clutch rocker and clutch rod with ball nut — newly made.
Typical problems this solves
- The original gearbox shaft has cracked or its splines are worn — replacements no longer exist
- A regulations-compliant limited-slip differential is missing for race entries
- A single drivetrain part would otherwise end the season
Why inquire here
A 904 belongs on the track, not on a shelf. Because gear cutting, hardening and grinding are in-house, replacement parts for this gearbox get made without the usual supply-chain odyssey — from sample to ready-to-install shaft.
In stock for the 904
- Complete gearbox, ready to install — built, set up, test-bench run; every fitted part available individually as a spare
- Final drive — ground, numbered, with measurement report
- Homologated gear pairs including the Nürburgring ratio