Propshaft couplings and cages---
105 series Alfa Romeo.

THIS PAGE HAS BEEN REMOVED AND THE INFORMATION IS NO LONGER VALID - PLEASE USE THE LINKS TO RETURN TO OUR SITE

List all News Items

In the 1960s and 1970s there was a problem with front prop-shaft couplings, which had a propensity to crack and break often with dire consequences. One of the first cars we dismantled for spares was a 1300 GT that had gone off the road when the front prop-shaft coupling had broken, the shaft had dropped and dug into the road lifting the car into a nearby ditch---a lesson was learned from this little misdemeanour. The rubber coupling (part number 105.00.15.300.00) wasn’t known for its longevity especially if the driver tended to be performance orientated. Cars built with competition in mind such as the GTA and TI Super were supplied new with a ‘competition cage’ to secure the rubber joint by providing added strength against adverse centrifugal force, and protection against breakage. This cage, a pressing, came in two parts—numbers 105.16.15.032.01 and 105.16.15.032.02.

In the 1960s Alfa Romeo supplied this cage as a replacement part for anyone building a normal 105 series Alfa for racing or competition. Factory Direzione Assistenza sheet 1.34.192 dated 1/7/68 and headed Sportive advises the fitting of a ‘competition cage’ before racing any 105 series car.

By the early 1970s the competition cage was no longer available but S.V.A.M. of Milan subsequently supplied a spun aluminium version. Nowadays we are seeing a resurgence of 105 series ‘racers’ that, thanks to the application of modern technology, are producing far greater performance than in their hey-day. It is essential under these conditions to again consider fitting the ‘competition cage’ to secure the front prop-shaft coupling under competition or fast road conditions. The latest version is laser cut, prepared in stainless steel, and comes in two parts fitting exactly as the original version of the 1960s. It has obviously been designed for present day race conditions or arduous road use---a 1960s design using 21st century technology.

Rubber couplings with bonded aluminium boltholes should be avoided, as these are prone to corrode causing the rubber to part from the aluminium resulting in a cracked or broken coupling---see illustration. Of the various makes of coupling available we recommend the more substantial Pirelli version to replace the old original 105.00.15.300.00 coupling that was designed almost fifty-years ago---and is still expected to be strong enough for the present day competition environment.