http://www.fiat124spiderservice.de/html ... wanne.html
(translation kindly provided by Google)
BIGGER GEAR OIL PAN WITH COOLING RIBS
Most of the problems of the 124 Spider transmission result from a relatively high oil temperature. In the 1500s, Fiat, from which this transmission originated , was around a lot of space to radiate heat. 124er at the ventilation is much lower because of the narrow space . In addition, the engine power and thus the load increased significantly. The engine rooms were sealed and the transmission tunnel insulation - insulation blankets and more isolated . All this has a gradual overheating of the transmission result , thus the housing expands excessively and sometimes so distorted that the gear is just hard to turn the shift linkage or even stuck.
It is also noted that, despite all the insulation is warm and the center console shift lever from time to time so hot that he can not be touched.
It overheated the oil, it ages prematurely and loses lubricity. Modern synthetic gear oils keep these temperatures , but are unsuitable because they cause rattling and running sounds constructively old gear with high storage games and coarse teeth . If so, a larger aluminum oil pan with 0.5 liters ( or about 30%) more oil capacity and cooling fins directly down
protrude into the airstream .