Passing gear gone
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Passing gear gone
I just noticed it this week, when I try to pass someone i normally just push down on the gas a go. I do that now and it seems like its lost all power but still RPM's up fast. Try it at a dead stop and it does the same, almost like it skips a gear. I can let off the gas and hit it again and it will go.
Appears to shift normally otherwise, just when I pass or "floor it" does it have this problem.
Any ideas???
Appears to shift normally otherwise, just when I pass or "floor it" does it have this problem.
Any ideas???
Hotshot
Joined: Jan 2004
Posts: 19,768
Likes: 1,082
From: St Louis
The transmission is almost completely computer controlled.
I'd start by running the self-tests to see if the computer is properly commanding the expected downshift and whether there are any EEC-V faults that may be causing shifting concerns. If the electronic commands are correct, then there may be hydraulic/mechanical concerns.
Here is the shift point test from the 02 service cd (4R70). Don't have the 03 data on this system, but the )2 stuff likely is the same.
I'd also focus on proper TPS operation...
Steve
I'd start by running the self-tests to see if the computer is properly commanding the expected downshift and whether there are any EEC-V faults that may be causing shifting concerns. If the electronic commands are correct, then there may be hydraulic/mechanical concerns.
Here is the shift point test from the 02 service cd (4R70). Don't have the 03 data on this system, but the )2 stuff likely is the same.
Shift Point Road Test
This test verifies that the shift control system is operating correctly.
1. Bring engine and transmission up to normal operating temperature.
2. Operate vehicle with transmission range selector lever in (D) position.
3. Note:
Shift speed ranges are approximate for all applications. For specific applications (engine, axle ratio and application) refer to the Automatic Transmission Specification Issue, available from Ford Customer Service Division.
Apply minimum throttle and observe speeds at which upshift occurs and torque converter engages; refer to the 4R70W Shift Speeds Chart in this section.
4. With the transmission in Overdrive (fourth gear), press the transmission control switch. The transmission should downshift to third gear. Release the accelerator pedal; engine braking should occur.
5. Press accelerator pedal to floor, wide open throttle (WOT). Transmission should shift from third to second gear, or third to first, depending on vehicle speed. Torque converter clutch should disengage and then reapply.
6. With the transmission in (D) position and speed above 80 km/h (50 mph) and less than half throttle, move the transmission range selector lever from (D) position to manual 2 position and remove pressure from the accelerator pedal. Transmission should immediately downshift into second gear. With vehicle remaining in manual 2 position, move the transmission range selector lever into manual 1 position, and release accelerator pedal. Transmission should downshift into first gear at speeds approximately below 45-56 km/h (28-35 mph).
7. If transmission fails to upshift/downshift or torque converter clutch does not apply and release, refer to «Diagnosis By Symptom» in this section.
4R70W Shift Speeds 4.6L F150 (3.08:1, 3.31:1, and 3.55:1 Axle Ratio)
Throttle Position Shift MPH
Light Throttle (TP
Voltage 1.25 Volts)
1-2 8-18
2-3 13-29
3-4 36-43
Closed Throttle
4-3 23-21
3-2 14-12
2-1 6-8
Wide Open Throttle
1-2 28-40
2-3 69-73
3-4 104
4-3 81-89
3-2 63-65
2-1 28-29
This test verifies that the shift control system is operating correctly.
1. Bring engine and transmission up to normal operating temperature.
2. Operate vehicle with transmission range selector lever in (D) position.
3. Note:
Shift speed ranges are approximate for all applications. For specific applications (engine, axle ratio and application) refer to the Automatic Transmission Specification Issue, available from Ford Customer Service Division.
Apply minimum throttle and observe speeds at which upshift occurs and torque converter engages; refer to the 4R70W Shift Speeds Chart in this section.
4. With the transmission in Overdrive (fourth gear), press the transmission control switch. The transmission should downshift to third gear. Release the accelerator pedal; engine braking should occur.
5. Press accelerator pedal to floor, wide open throttle (WOT). Transmission should shift from third to second gear, or third to first, depending on vehicle speed. Torque converter clutch should disengage and then reapply.
6. With the transmission in (D) position and speed above 80 km/h (50 mph) and less than half throttle, move the transmission range selector lever from (D) position to manual 2 position and remove pressure from the accelerator pedal. Transmission should immediately downshift into second gear. With vehicle remaining in manual 2 position, move the transmission range selector lever into manual 1 position, and release accelerator pedal. Transmission should downshift into first gear at speeds approximately below 45-56 km/h (28-35 mph).
7. If transmission fails to upshift/downshift or torque converter clutch does not apply and release, refer to «Diagnosis By Symptom» in this section.
4R70W Shift Speeds 4.6L F150 (3.08:1, 3.31:1, and 3.55:1 Axle Ratio)
Throttle Position Shift MPH
Light Throttle (TP
Voltage 1.25 Volts)
1-2 8-18
2-3 13-29
3-4 36-43
Closed Throttle
4-3 23-21
3-2 14-12
2-1 6-8
Wide Open Throttle
1-2 28-40
2-3 69-73
3-4 104
4-3 81-89
3-2 63-65
2-1 28-29
Steve
Last edited by projectSHO89; Jun 16, 2006 at 09:20 AM.
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Well I did try to verify the shift points and everything seemed to go properly at normal speeds.
I disconnected the battery to reset the computer. I then followed the directions in the manual for "resetting" the truck. I drove it for the 10 miles it suggested, then jumped on it, everything shifted great. I am shifting the way it used to at least. The only thing is I can hear a small squeak when it goes from 4th to 5th at 5k RPM's.
Thanks for all the help.
I disconnected the battery to reset the computer. I then followed the directions in the manual for "resetting" the truck. I drove it for the 10 miles it suggested, then jumped on it, everything shifted great. I am shifting the way it used to at least. The only thing is I can hear a small squeak when it goes from 4th to 5th at 5k RPM's.
Thanks for all the help.
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