The 5586641 Eaton Fuller Heat Exchanger sits in the Heat Exchanger group of the factory parts list for five units: RTLO-18610B, RTLO-18610B-T2, RTLO-18918B-T2, RTLOF-18610B and RTLOF-18918B-T2. In each it is item 3, quantity 1 per assembly.
This is a water-to-oil transmission cooler. Engine coolant takes heat out of the gear oil and delivers it to the truck's main cooling package, so cooling does not rely on road speed or airflow, and a cold transmission gets up to temperature faster. A cooler that leaks internally can let coolant into the gear oil, which harms synchronizers and bearings. Not sure it is your part? Give us a call at Pro Gear and Transmission.
Features
Eaton Fuller heat exchanger, part number 5586641
Item 3, quantity 1 per assembly, in the Heat Exchanger group
Listed for RTLO-18610B, RTLO-18610B-T2, RTLO-18918B-T2, RTLOF-18610B and RTLOF-18918B-T2
Engine coolant carries away gear oil heat, independent of airflow
A leak between oil and coolant sides can contaminate the gear oil
