4x4 engaged then neutral
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4x4 engaged then neutral
Truck - 1994 F-150, Step side, extended cab, 4x4 (push button), 5.8L, Auto,180k miles
Issue: Truck was making a noise in the front driver hub like the driveshaft wanted to engage (auto hubs). Drove it in 4wd and it stopped but when I came to a stop the truck acts like its in neutral, the truck wont move and the engine just revs up when I try to drive. I can take it out of 4wd and go into 2wd and the truck will move on it own again. Took it to a shop, they duplicated the issue on the rack. I was told the transfer case was goin out so I purchased a rebuilt one, they installed it but noticed the transfer case switch module was bad. I found a good used one, they installed it and took it for a test drive. Truck drives in 4wd until you come to a stop, it acts like its in neutral...still.
I did take both front hubs apart and everything looked good, went ahead and put new bearings in the driver side. When I bought the truck the 4wd didn't work, it was just the transfer case motor, it is new.
Anyone else run into an issue like this? Any clue where to look next?
Issue: Truck was making a noise in the front driver hub like the driveshaft wanted to engage (auto hubs). Drove it in 4wd and it stopped but when I came to a stop the truck acts like its in neutral, the truck wont move and the engine just revs up when I try to drive. I can take it out of 4wd and go into 2wd and the truck will move on it own again. Took it to a shop, they duplicated the issue on the rack. I was told the transfer case was goin out so I purchased a rebuilt one, they installed it but noticed the transfer case switch module was bad. I found a good used one, they installed it and took it for a test drive. Truck drives in 4wd until you come to a stop, it acts like its in neutral...still.
I did take both front hubs apart and everything looked good, went ahead and put new bearings in the driver side. When I bought the truck the 4wd didn't work, it was just the transfer case motor, it is new.
Anyone else run into an issue like this? Any clue where to look next?
Lead Driver
Joined: Oct 2016
Posts: 6,185
Likes: 633
From: Houston/Sugar Land
Here is a forum post that may help you. And you should run codes if the auto is an E4OD as it is electronically controlled.
Wrong Gear Starts
Bad or mis-adjusted MLPS
Can cause wrong gear starts, no upshift, falls out of gear, and high line pressure = harsh upshift and engagements. May or may not set code 67/634 (MLPS out of position).
Note
MLPS is located on driver's side of transmission case.
MLPS adjustment
Place manual lever in Neutral. Line up I.D mark on sensor with l.D. mark on plastic bushing. Tighten bolts.
To check MLPS
1. Hook red lead of DVOM to pin # 199 (MLP sensor signal).
2. Hook black lead of meter to pin 359 (sensor signal return).
3. Set meter to ohms.
4. Move manual lever through the different positions and compare DVOM reading to chart below.
Manuel lever position
Meter should read:
P 3769 to 4608 ohms
R 1304 to 1593 ohms
N 660 to 807 ohms
D .... 361 to 442 ohms
2 190 to 232 ohms
I 80 to 95 ohms
Important
If the MLPS needs replacement, use Ford part # E5TZ-7A247-A. This kit includes a new style harness connector. You must replace the connector to use the new MLPS. By sliding the old wire separator from the original connector up the harness you can leave it in place as you install the new connector. This helps to keep the wires in their original location.
Note
Make sure you clean the harness connector with brake clean and apply some dielectric grease to the pins. This will ensure a good connection. Use Permatex part # 67V (dielectric tune-up grease). You can get it at most auto parts stores.
Not saying your MLPS is bad but I saved $40 going to Napa instead of a dealership when I replaced mine.
Regarding Code 62:
Before or after overhaul code 62/628 (TCC slippage).
Code 62/628 will set when the computer calls for LU but does not see
1. Change in rpm (no LU at all- electrical or mechanical problem).
2. Enough of a change in rpm (converter clutch or forward, intermediate, direct or OD clutches slipping). Usually converter clutch then directs.
Cause and correction
Mechanical
Listed by most common
1. Warped or cracked LU piston. This is the most common and number one reason for code 62/628. Ford completely redesigned the piston making it much stronger. LUK manufactures the new piston for Ford and when you buy a rebuilt torque converter always specify that you want it with the updated piston. The rebuilt converter costs more money because of the updated piston but it eliminates the most common cause of code 62/628.
2. Slipping direct clutch (especially common in diesels) Make sure your using E4OD frictions and not C6. All diesels should use 4 frictions in direct. Use only steel sealing rings on center support to prevent high clutch circuit leaks.
3. Pump- A worn pump with excessive side gear clearance will produce low pump pressure, which can be enough to cause the converter clutch to not hold or slip setting code 62/628. Make sure the pump you're using is perfect. If not and you have to replace it Ford has a updated pump assembly with larger gears for increased volume part # F5TZ-7A103-A.
4. Make sure converter clutch shift and apply valves in the stator are not sticking or that the springs are not mixed up.
Electrical
Listed by most common
1.RPM sensor
Diesel only- very common Ford part # E5TZ-17B384-A. May or may not set code 14/211 (RPM sensor circuit failure). A bad RPM sensor can cause LU and/ or the shifls to go in and out (cycle back and forth).
Check RPM sensor with DVOM set to on AC voltage. RPM sensor is
located below the engine oil filler neck in the housing.
Here's how to check it
1. Remove 2-wire connector end.
2. Hook meter leads to pins on sensor. It doesn't matter which way you hook up the red or black leads.
3. Set scale to AC/ 0 to 40-volt scale..
4. Start engine in park. Raise rpm while watching DVOM.
5. Voltage must increase or RPM sensor is bad.
2. VSS
May or may not set code 29/452 (VSS speed sensor signal too low).
Note
Check speed sensor with DVOM on AC scale. VSS is located in transmission tail housing or differential.
Here's how to check it:
1. Remove 2-wire connector end.
2. Hook meter leads to pins on sensor. It doesn't matter which way you hook up the red or black leads.
3. Set scale to AC voltage / 0 to 40 volt scale.
4. Raise vehicle so rear wheels are off ground.
5. Start vehicle, put in "D" and make transmission upshift. Watch meter.
6. You must see an increase in AC voltage or VSS is bad
3. Bad LU solenoid in solenoid block.
4. Bad TOT sensor (transmission oil temperature) in solenoid block
5. Open or shorted wire between LU solenoid and controller.
6. Poor connection at LU solenoid.
Also, is the ground on the FIPL at or lower than 1/10th of a volt (.100 volts on a meter? If not, you need to get it there as it is critical. The MLPS ground and TOT ground are all on the same circuit going back to the PCM. If you haven't got the time to trace out the ground wires, simply splice into the ground wire of the FIPL and run the other end to the ground of the passenger side battery. This will clear up the crap signals going to the computer by the FIPL, TOT, MLPS (direct experience). R.A.
Wrong Gear Starts
Bad or mis-adjusted MLPS
Can cause wrong gear starts, no upshift, falls out of gear, and high line pressure = harsh upshift and engagements. May or may not set code 67/634 (MLPS out of position).
Note
MLPS is located on driver's side of transmission case.
MLPS adjustment
Place manual lever in Neutral. Line up I.D mark on sensor with l.D. mark on plastic bushing. Tighten bolts.
To check MLPS
1. Hook red lead of DVOM to pin # 199 (MLP sensor signal).
2. Hook black lead of meter to pin 359 (sensor signal return).
3. Set meter to ohms.
4. Move manual lever through the different positions and compare DVOM reading to chart below.
Manuel lever position
Meter should read:
P 3769 to 4608 ohms
R 1304 to 1593 ohms
N 660 to 807 ohms
D .... 361 to 442 ohms
2 190 to 232 ohms
I 80 to 95 ohms
Important
If the MLPS needs replacement, use Ford part # E5TZ-7A247-A. This kit includes a new style harness connector. You must replace the connector to use the new MLPS. By sliding the old wire separator from the original connector up the harness you can leave it in place as you install the new connector. This helps to keep the wires in their original location.
Note
Make sure you clean the harness connector with brake clean and apply some dielectric grease to the pins. This will ensure a good connection. Use Permatex part # 67V (dielectric tune-up grease). You can get it at most auto parts stores.
Not saying your MLPS is bad but I saved $40 going to Napa instead of a dealership when I replaced mine.
Regarding Code 62:
Before or after overhaul code 62/628 (TCC slippage).
Code 62/628 will set when the computer calls for LU but does not see
1. Change in rpm (no LU at all- electrical or mechanical problem).
2. Enough of a change in rpm (converter clutch or forward, intermediate, direct or OD clutches slipping). Usually converter clutch then directs.
Cause and correction
Mechanical
Listed by most common
1. Warped or cracked LU piston. This is the most common and number one reason for code 62/628. Ford completely redesigned the piston making it much stronger. LUK manufactures the new piston for Ford and when you buy a rebuilt torque converter always specify that you want it with the updated piston. The rebuilt converter costs more money because of the updated piston but it eliminates the most common cause of code 62/628.
2. Slipping direct clutch (especially common in diesels) Make sure your using E4OD frictions and not C6. All diesels should use 4 frictions in direct. Use only steel sealing rings on center support to prevent high clutch circuit leaks.
3. Pump- A worn pump with excessive side gear clearance will produce low pump pressure, which can be enough to cause the converter clutch to not hold or slip setting code 62/628. Make sure the pump you're using is perfect. If not and you have to replace it Ford has a updated pump assembly with larger gears for increased volume part # F5TZ-7A103-A.
4. Make sure converter clutch shift and apply valves in the stator are not sticking or that the springs are not mixed up.
Electrical
Listed by most common
1.RPM sensor
Diesel only- very common Ford part # E5TZ-17B384-A. May or may not set code 14/211 (RPM sensor circuit failure). A bad RPM sensor can cause LU and/ or the shifls to go in and out (cycle back and forth).
Check RPM sensor with DVOM set to on AC voltage. RPM sensor is
located below the engine oil filler neck in the housing.
Here's how to check it
1. Remove 2-wire connector end.
2. Hook meter leads to pins on sensor. It doesn't matter which way you hook up the red or black leads.
3. Set scale to AC/ 0 to 40-volt scale..
4. Start engine in park. Raise rpm while watching DVOM.
5. Voltage must increase or RPM sensor is bad.
2. VSS
May or may not set code 29/452 (VSS speed sensor signal too low).
Note
Check speed sensor with DVOM on AC scale. VSS is located in transmission tail housing or differential.
Here's how to check it:
1. Remove 2-wire connector end.
2. Hook meter leads to pins on sensor. It doesn't matter which way you hook up the red or black leads.
3. Set scale to AC voltage / 0 to 40 volt scale.
4. Raise vehicle so rear wheels are off ground.
5. Start vehicle, put in "D" and make transmission upshift. Watch meter.
6. You must see an increase in AC voltage or VSS is bad
3. Bad LU solenoid in solenoid block.
4. Bad TOT sensor (transmission oil temperature) in solenoid block
5. Open or shorted wire between LU solenoid and controller.
6. Poor connection at LU solenoid.
Also, is the ground on the FIPL at or lower than 1/10th of a volt (.100 volts on a meter? If not, you need to get it there as it is critical. The MLPS ground and TOT ground are all on the same circuit going back to the PCM. If you haven't got the time to trace out the ground wires, simply splice into the ground wire of the FIPL and run the other end to the ground of the passenger side battery. This will clear up the crap signals going to the computer by the FIPL, TOT, MLPS (direct experience). R.A.
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