Question About Overdrive
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Joined: Oct 2003
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From: Douglassville,Pa
Question About Overdrive
I'm a new to this board and i have a 97 F-150 4/4.I noticed that when i take it of overdrive that the Rpm's go to about 21/2 rpm and when i put the overdrive on it goes back down to 1 1/2 rpm at 55mph.Is this normal i had the truck for about 10 months now and have the trans filter changed and fluid changed(Not superflushed)Any help would be great Darren Landis
feel free to email me at MXZSNW@AOL.COM
feel free to email me at MXZSNW@AOL.COM
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Joined: Sep 2000
Posts: 1,704
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From: Mpls, MN
Your truck sounds as though the transmisison is functioning fine. Whether you have a 4R70W or a 4R100, they are both 4-speed automatics with overdrive.
The button at the end of the shift lever controls whether or not 4th gear will engage. With O/D Off, you will only use gears 1-3. With O/D On, you will use all 4 gears. Even when you select O/D Off, the torque conveter will still lock in 3rd gear to increase fuel mileage, you just won't go into 4th gear.
When you are going down the highway at 55mph in O/D and you turn it off, you are dropping the transmission from 4th gear with the torque converter locked, into 3rd grea with the torque converter unlocked. The torque converter will reengage in 3rd gear after a moment if you are not under load.
The button at the end of the shift lever controls whether or not 4th gear will engage. With O/D Off, you will only use gears 1-3. With O/D On, you will use all 4 gears. Even when you select O/D Off, the torque conveter will still lock in 3rd gear to increase fuel mileage, you just won't go into 4th gear.
When you are going down the highway at 55mph in O/D and you turn it off, you are dropping the transmission from 4th gear with the torque converter locked, into 3rd grea with the torque converter unlocked. The torque converter will reengage in 3rd gear after a moment if you are not under load.