# 4.44 gear ratio 3406 B model cat 18 speed

Hi I was looking at a 1979 kenworth A model with 4.44 gear ratio 3406 B model cat 18 speed 11r24.5. Was trying to figure out what the top speed would be.

Is this a worthwhile discussion?

13318
# 4.44 gear ratio 3406 B model cat 18 speed

Discussion Topic

Rep: 1

Hi I was looking at a 1979 kenworth A model with 4.44 gear ratio 3406 B model cat 18 speed 11r24.5. Was trying to figure out what the top speed would be.

Filter by:

Most Helpful Answer

Rep: 369

If it's a later model 18 speed with a double over, 1530 rpm @ 60 mph. Hope they adapted the air to air with it. You'll have to keep the tall tires though, should run 65-70 mph, 4.8 - 5.2 mpg at those speeds however. At 60mph, the speed limit was 55 mph back then, I could get 5.8 - 6.2 mpg on a nice day.

Rep: 707

It's going to depend on what the final ratio of the transmission is. Many 18 spds are 0.73-0.76 and with 4.33 ratio your are going to be at 1800 or more rpms at 60mph. I'm not familiar with the older transmissions but if you get us the model number we can calculate your RPMs exactly.

Rep: 13

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 4

All Time: 52