Ok my dad has a stock 1993 cummins 1 ton 4x4 that has 180k on the clock. . The injector pump started to leak, so he had it replaced by a local mechanic... . After aprox 200 miles he went to crank it up and it locked up... He took it back to the mechanic, and turns out the gear on the injector pump was broke and the pin in the gear on the crankshaft was sheared. So now the gear needs to be replaced, and the pin also. . Why would the gear break??? The mechanic said that it is from fatigue and miles... . I just wanted your input on why something like this might occur. . Could it be from improper install???? Thanks Wesley