The transmission fluid is clean, there is no sign of metal on the magnet and I know nothing about this type of transmission. have had plenty of exerience with early Land Rovers, Unimogs, 4x4 and 6x6 International trucks, Scamel truck, Kieser and much more. The switch on the shift appears to function with the dash light turning on and off when the button is pushed but no joy with 4th gear engaging. The thurmo fan does not come on at all and the engine seems to run quite cool. If the engine was not getting up to correct running temp could this cause the trans to not change? I read in the forums about this but does this only refer to the transmission temp?