Info on how the 4L60E operates
I don't know how detailed towards the 4L60E you were trying to get but here is a link to information on how auto transmissions work
http://auto.howstuffworks.com/automa...ansmission.htm
http://auto.howstuffworks.com/automa...ansmission.htm
Well, okay.
The 4L60-E is technically a two-speed auto with overdrive.
The first gearset is called the input planetary. The second one is the overdrive.
First gear is nothing engaged but the forward clutch.
Second gear is overdriven first. The overdrive is energized by a band.
Third gear is direct drive, input speed = output speed. Direct is a engaged by a clutch pack often called the "3-4 set."
Forth gear is overdriven direct.
The 4L60-E gets 4 gear ratios from only 2 planetaries. To do this it must engage and disengage the overdrive.
1-2 shift = band engage
2-3 shift = band disengage, 3-4 clutches simutaneously engage
3-4 shift = band engage
Compare that to a TH400, for example that gets only 3 speeds, but also from 2 planetaries. Each shift is a single event with clutches, not a band to shift.
1-2 shift = intermediate clutch pack engage
2-3 shift = direct clutch pack engage
Further, compare to a 4L80-E. The 80 has 3 planetary gearsets. Each shift is also a single event. Three planetaries, four speeds, and all upshifts are handled by clutch packs, not band(s)
1-2 shift = intermediate clutch pack engage
2-3 shift = direct clutch pack engage
3-4 shift = overdrive clutch pack engage
The 4L60-E is technically a two-speed auto with overdrive.
The first gearset is called the input planetary. The second one is the overdrive.
First gear is nothing engaged but the forward clutch.
Second gear is overdriven first. The overdrive is energized by a band.
Third gear is direct drive, input speed = output speed. Direct is a engaged by a clutch pack often called the "3-4 set."
Forth gear is overdriven direct.
The 4L60-E gets 4 gear ratios from only 2 planetaries. To do this it must engage and disengage the overdrive.
1-2 shift = band engage
2-3 shift = band disengage, 3-4 clutches simutaneously engage
3-4 shift = band engage
Compare that to a TH400, for example that gets only 3 speeds, but also from 2 planetaries. Each shift is a single event with clutches, not a band to shift.
1-2 shift = intermediate clutch pack engage
2-3 shift = direct clutch pack engage
Further, compare to a 4L80-E. The 80 has 3 planetary gearsets. Each shift is also a single event. Three planetaries, four speeds, and all upshifts are handled by clutch packs, not band(s)
1-2 shift = intermediate clutch pack engage
2-3 shift = direct clutch pack engage
3-4 shift = overdrive clutch pack engage
Great info 
