Walter Buller
Member
The 1993 12V 5.9L Cummins motor that we put into a 1994 Chevy dually has a cylinder under the exhaust manifold and forward of the turbo that is about 4" in diameter and about 15"-17" long. There is a coolant line on each end. The front coolant line starts from near the bottom of the head up front. The rear coolant line starts from the header at the bottom radiator hose. One mechanic said it was a heat exchanger for the fluid in the automatic transmission. Another one said it was a manual transmission oil cooler. Which one is right, and would it hurt anything to disconnect it on a truck with an NV4500 5 speed manual transmission? I'd appreciate some input on this.