Transmission Ratios
11-23-2012, 07:02 PM
#1
Dailydriving300ci-of-fury
Thread Starter
Transmission Ratios
Hey guys. I'm trying to figure out some ratios for a friend that wants a 4 spd manual or a 5 spd manual truck. Someone here told me that the 4th gear in the 4 spd manual trannys is the same as the last gear in the C6 automatics. Is this true? Also, is the final gear in the 4 spd manual with out a granny gear any different than the 4 spd manual with a granny gear? He's looking at a 83 Bronco that may have either 4 spds in it but I'd be curious if any of the ratios changed in 87-91 as well. Thanks
11-23-2012, 09:33 PM
#2
Senior Member
On most 4 speeds the fourth gear is 1:1. Some have granny gears others don't. Ford did use a 4 speed overdrive for a few years on vans and pick ups in the early 80s that did have an OD fourth. Most five speeds on light duty trucks will have the 1:1 fourth gear and an overdrive fifth.
The BW T18, T19, and NP 435 are the popular 4 speeds found in Ford trucks and are 1:1 in fourth. The two five speeds are the Mazda and ZF units. The Mazda is a light duty box but both of mine reached 200k with out any issues with some hauling. The ZFs was found mostly on the F 250s and are capable of heavier loads.
The C6 third gear is 1:1 while the AOD and E40D are 4 speed overdrive units with third being 1:1 and fourth is an overdrive. Most autos will lock the torque converter in third and fourth.
regards
rikard
The BW T18, T19, and NP 435 are the popular 4 speeds found in Ford trucks and are 1:1 in fourth. The two five speeds are the Mazda and ZF units. The Mazda is a light duty box but both of mine reached 200k with out any issues with some hauling. The ZFs was found mostly on the F 250s and are capable of heavier loads.
The C6 third gear is 1:1 while the AOD and E40D are 4 speed overdrive units with third being 1:1 and fourth is an overdrive. Most autos will lock the torque converter in third and fourth.
regards
rikard
