1972 915 gearbox for 2.5 S/T: 915/35

[matteo68]

Does anyone have the specification for the 915 gearbox fitted to the 1972 2.5 S/T at all?

I have done some research and believe that it may have been type no. 915/35, similar to the later 915/08 fitted to the '73 RS (although don't quite understand why the numbering was so out of sequence), and fitted with an internal oil pump on the front transmission cover with mechanical speedo, but I don't believe it had an external oil cooler fitted like the 930?

The other significant difference to 915/08 appears to be the choice of racing gear ratios, as listed in "Information regarding Porsche Vehicles used for Sports Purposes 2 Ed" and also the 72MY Competition Spare Parts List. Indeed the latter lists, in the section headed 'LUBRICATION OF TRANSMISSION WITH OIL PUMP', all the various parts required for transmission lubrication, but there is no mention of an external cooler anywhere, so I believe this must have been a later upgrade, as the front fender-mounted oil coolers were - originally at least - intended for engine cooling, not gearbox cooling in '72.



I have found these resources, including the relevant page from PET (Group 302-30) which help to clarify to a degree, but I would be very grateful for any other advice and knowledge of this aspect of the '72 S/T:

http://www.gboxweb.com/915specs.html

https://www.cogscogs.com/Transmissio...-30_c_601.html



It seems that Cogscogs, Einmalig and others appear to have all / most of the required parts, apart from 'Porsche Cover Oil Pump Complete with Bearing Sleeve' (part # 915.307.033.00) - does anyone have any ideas as to where this could be found, or alternatively have one they would be prepared to sell?

[gled49]

I did one a few years ago. It was a 915/xx, no type number with ratios to order. Only 15 listed serial numbers. It’s the last trans with no type (—) listed for 72 in the small spec book. The number stamped on it was 915/11 + the serial number, which fell within the 15 listed. It translated to 915/xx/11 as it had a limited slip. The oil pump was all prototype for internal pumping, with needle bearings instead of bushings and just happened to have the shortest ratios available at the time. Very special box in my opinion. Hope this helps. G