BOXSTER HAUS

May 2026 (selection)

1974 Porsche 911 Engine 2.7 140,000km.
5-Speed. (LHD) Owner Simon. A

Brief: Inpect & Repair 5th gear whine in 915 Gearbox.

Having already removed the engine and gearbox in preparation for the 3.0-litre (from a 78 SC 911), Simon mentioned that the gearbox had an annoying whine in 5th gear.

Unfortunately, once we removed the 5th gear cluster cover, a rogue (loose) broken 5mm stud and nut fell out (see row 2, image 1). Most concerning! No choice, we had to completely strip the gearbox and find the origin of the stud. The 5th-gear cluster bearing required replacement, but it would have been nonsensical to ignore the stud. Not only did we strip the gearbox, but we also dismantled the differential assembly. Other than several worn bearings, there was no sign of breakage.

Quite bizarre and a little frustrating! Three of us double and triple-checked, nothing; the gearbox and diff were intact. The gearbox had been dismantled, not surprisingly, as the 911 was 50 years old. Our conclusion? A previous mechanic dropped a broken stud, perhaps from an engine he was working on, obviously quite unaware of such an extraordinary occurrence; no damage occurred.

1977 Porsche 911 2.7
Sportsmatic, Owner Ryan K. 65,500k

Brief: Keep her well charged.

Having rebuilt the complicated (sensitive) Sportsmatic electronic (Clutchless) gear lever function, it soon became apparent that unless the alternator was charging at 100%, gear-changing functionality was compromised. After 15 minutes of driving, it was very difficult to change manually. Ryan’s 911 had a 4-speed Sportomatic fitted at some time. Around town, you can live in D1, but it's far too low for highway driving, which is why you need to change manually.

Originally, the 77 911s ran a 55-AMP alternator with an external Valeo (French) voltage regulator. The new Alternator was a Power-Light 160 AMP. Although they claim it is a direct fit, it actually is not. Different-sized cables.