1999 911 996 Carrera 4
A while ago, the horn started to sound intermittently, particularly when going over bumps in the road etc. There's a wealth of info about this problem online, and I diagnosed the deteriorating rubber bushes where the steering column airbag supporting frame attaches to the wheel. Got it apart (the concealed Torx30 screws accessed via holes in the back of the wheel has to be the worst piece of design I've ever seen on any vehicle), and applied one of the recommended fixes - silicone sealant on the bushes to stiffen them up.
This worked after a fashion, but it soon became clear that the job wasn't good enough, and after another try, I decided to try a different approach. I sourced four little spacers, about 3 mm wide, from some plastic cupboard fittings, and installed one under each bush to hold the frame further away from the wheel and horn contacts. Very pleased with my solution, until I was amazed to find that it didn't make any difference! There is still hardly any travel in the airbag/horn assembly before the horn sounds. I took it all apart again and studied the way the airbag and frame fit together and for the life of me I can't see how it's not working. The travel is probably a good few millimetres when the airbag is offered up to the frame, but as soon as the screws are tightened it all but disappears. But the screws just clamp the frame to the airbag! So how can that draw the whole thing closer to the wheel???
It's all so simple mechanically, but I just don't get what's going on. Driving me mad - and keeping the car off the road in the drive with the battery disconnected! Has anybody got any ideas?
Many thanks.
A while ago, the horn started to sound intermittently, particularly when going over bumps in the road etc. There's a wealth of info about this problem online, and I diagnosed the deteriorating rubber bushes where the steering column airbag supporting frame attaches to the wheel. Got it apart (the concealed Torx30 screws accessed via holes in the back of the wheel has to be the worst piece of design I've ever seen on any vehicle), and applied one of the recommended fixes - silicone sealant on the bushes to stiffen them up.
This worked after a fashion, but it soon became clear that the job wasn't good enough, and after another try, I decided to try a different approach. I sourced four little spacers, about 3 mm wide, from some plastic cupboard fittings, and installed one under each bush to hold the frame further away from the wheel and horn contacts. Very pleased with my solution, until I was amazed to find that it didn't make any difference! There is still hardly any travel in the airbag/horn assembly before the horn sounds. I took it all apart again and studied the way the airbag and frame fit together and for the life of me I can't see how it's not working. The travel is probably a good few millimetres when the airbag is offered up to the frame, but as soon as the screws are tightened it all but disappears. But the screws just clamp the frame to the airbag! So how can that draw the whole thing closer to the wheel???
It's all so simple mechanically, but I just don't get what's going on. Driving me mad - and keeping the car off the road in the drive with the battery disconnected! Has anybody got any ideas?
Many thanks.
