10 speeds are tough

Truck Shop

Well-known member
This is a FRO 16210C with internal cooler I changed out this last Thursday and Friday. Technically it has 34,000 hours and 901,000 miles on it.
Internal cooler leaked three gallons of coolant inside. It had coolant whipped 50 wt synthetic goo running out the front bearing cover and was
pushing it out the shift tower. But it was still running quiet according to the driver;). This trans had a 455 Hp 1750 torque C-15 cat in front of it
and moved 105,500 daily. Some drivers may not like 10 spd's but they will out last most every thing else because there simple.

Truck Shop



Active member
Those transmissions with an external engine coolant transmission cooler do equally well. Fills the cooling system up with snot near impossible to remove. Transmission had green slim synthetic oil. How does that happen with red coolant and synthetic gear oil? It is not in the color chart. Transmission lasted 6 months longer than the cooler. About 400,000 miles.