Gearbox Shifts Hard or Crunches

Typical causes — by gearbox type

Hard-shifting classic Porsche gearboxes follow familiar patterns, depending on the series:

• 915 gearbox (911, 1972–1986)+

  the crunching second gear is the 915 classic — worn synchromesh and dog teeth.
• G50 and 964+

  stiff, notchy shifting despite the robust reputation — usually synchro rings and guide sleeves.
• 901 gearbox of the early 911+

  crunching gears and worn synchromesh after decades of use — the 902 shows the same picture, the 912 worn synchromesh and a notchy shift.
• 914+

  notchy shifting — here often a combination of the shift linkage and worn guide sleeves inside the gearbox.

What happens in a rebuild

In a rebuild to factory specification the gearbox is fully stripped; all bearings, synchromesh and shift elements are inspected and the ring and pinion is set up. Every part is cleaned, checked and measured — only on that basis can anyone say what is really needed, and you receive a binding quote.

Whatever is no longer available we machine on our own equipment — from dog rings to a complete final drive. That matters most on types where the parts market has thinned out.

Checked, not assumed

At the end, every reconditioned gearbox runs on the test bench before it leaves the building: all gears are shifted, and smooth running, shift quality and sealing are checked under real conditions. You install a proven gearbox — not an assembled one making its first metres in your car.

Getting it to us is simple: remove the gearbox and send it in — drain the oil, pack it securely, add a short description of the problem. We take it from there.