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.Nardella 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.
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 happen without the usual supply-chain odyssey — from sample to ready-to-install shaft.