I also wonder if part of it is the design of the 4 speed automatic transmissions......
I've driven gas and diesel 4 autos,
My Excursion is a 5 Speed (5r110)
My 2 F-150 are V-6 Gas 6 Speed Autos.
There is a huge difference in the way the 4 speed act vs, the 5 and 6 Speed
These have all been in factory trim, but the way the 4 speeds are, I understand why everyone wants to do a ZF-5 Swap. They are a "slush box". I know of a couple people that have put a tuner on a 7.3 PSD just to adjust the way the transmission works. Any 4 speed that I've had that has the O/D Lockout doesn't like and probably shouldn't tow in O/D (my opinion) (I've also gotten hooked on the Precision Transmission channel on YouTube: https://www.youtube.com/channel/UCYAAY7V9ifGS7Q8S35EFVnw and he does a good job of explaining how and why the transmissions he is tearing apart fail. He even has a few E4OD/4r100 videos on there)
I even recently test drove an F-150 with the 5.4 V-8 and 4 speed. It was the same "slush box" feeling as the 30 year old E4's feel. Was not impressed. With the power and gearing, I'm quite sure my 3.7 V-6 would have left that 5.4 sitting......
The 5 speed behind the 6.0/6.4 were light years ahead of the E4/4r transmission. They shift when they should, you can tow in all 5 gears, and the Tow/Haul mode really works. It completely changes the shift schedule and will also engine brake very effectively.
The 6 speeds are even more refined. Have Tow/Haul that really works. Has a very effective RPM range for the engine and gearing. Cruising at 55ish, it runs at 12-1300 rpm.... just puts along, but also works well towing. Plus with the way they control the newer transmissions, it really helps with the economy.
I would like to drive a truck with the new 10 speed transmission...... that would be an interesting comparison to the others....
I've driven gas and diesel 4 autos,
My Excursion is a 5 Speed (5r110)
My 2 F-150 are V-6 Gas 6 Speed Autos.
There is a huge difference in the way the 4 speed act vs, the 5 and 6 Speed
These have all been in factory trim, but the way the 4 speeds are, I understand why everyone wants to do a ZF-5 Swap. They are a "slush box". I know of a couple people that have put a tuner on a 7.3 PSD just to adjust the way the transmission works. Any 4 speed that I've had that has the O/D Lockout doesn't like and probably shouldn't tow in O/D (my opinion) (I've also gotten hooked on the Precision Transmission channel on YouTube: https://www.youtube.com/channel/UCYAAY7V9ifGS7Q8S35EFVnw and he does a good job of explaining how and why the transmissions he is tearing apart fail. He even has a few E4OD/4r100 videos on there)
I even recently test drove an F-150 with the 5.4 V-8 and 4 speed. It was the same "slush box" feeling as the 30 year old E4's feel. Was not impressed. With the power and gearing, I'm quite sure my 3.7 V-6 would have left that 5.4 sitting......
The 5 speed behind the 6.0/6.4 were light years ahead of the E4/4r transmission. They shift when they should, you can tow in all 5 gears, and the Tow/Haul mode really works. It completely changes the shift schedule and will also engine brake very effectively.
The 6 speeds are even more refined. Have Tow/Haul that really works. Has a very effective RPM range for the engine and gearing. Cruising at 55ish, it runs at 12-1300 rpm.... just puts along, but also works well towing. Plus with the way they control the newer transmissions, it really helps with the economy.
I would like to drive a truck with the new 10 speed transmission...... that would be an interesting comparison to the others....