Transmission not working properly

Tiny
TATU WOODY
  • MEMBER
  • 1997 FORD F-150
  • 4.6L
  • V8
  • 4WD
  • AUTOMATIC
  • 130,000 MILES
Truck starts in park or neutral. When put in gear, reverse, or drive, the RPMs will go down like it's engaging but acts like it is still in neutral. Truck won't move. When put back in park the parking pin sounds like it's grinding. Wont lock tires out. Will roll with it in park. The code tripped says it's the shift module behind the fuse box. But why would it not lock out in park? I can see maybe the fluid pressure sensor not engaging but is there some way to check this out?
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Thursday, November 18th, 2021 AT 1:19 PM

13 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

That sounds like the transmission is working but there is a broken link in the system. Are driveshafts, drive axles, and so on, in good condition?

When you place it in park, does park engage or does it act like it's still in neutral? Also, is the noise you hear loud enough for you to record and upload for me to hear? Are you sure the transfer case didn't get accidentally put in neutral?

Let me know.

Joe
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Thursday, November 18th, 2021 AT 8:14 PM
Tiny
TATU WOODY
  • MEMBER
When I put it in park it sounds like when you put it in park while it's rolling. Grinding sound. Goes up and down with RPMs. Diagnostic tool says no torque converter power. Plus, shift module confused on gear position. Friend says maybe park lock sheared and fragments clogged fluid pressure. I thought maybe transfer case could have been in neutral too but if that was the case wouldn't it show up MPH on the dash while in drive?
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Thursday, November 18th, 2021 AT 8:47 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

Anything is possible. However, when the vehicle is off and in park, can you still push it as if it is in neutral? The idea that you hear the parking sprag grinding tells me the transmission is turning internally as it should, but there is something disconnecting it from the wheels.

Let me know.

Joe
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Thursday, November 18th, 2021 AT 8:53 PM
Tiny
TATU WOODY
  • MEMBER
Yes, the truck rolls while in park. It has an electric 4x4 switch. Diagnostic shows whatever we switched to. Tork converter shows 0 percent.
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Thursday, November 18th, 2021 AT 9:05 PM
Tiny
TATU WOODY
  • MEMBER
First gear shows up on tool as first.
Second says second.
Drive says first gear.
Park reverse and neutral as in first gear.
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Thursday, November 18th, 2021 AT 9:10 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
If you can move it in park, then somewhere it's disconnected. The park sprag is moved mechanically, so I don't feel the converter is causing the issue.

When you say 0%, for the torque converter, exactly what is being checked? Also, could you let me know the actual codes that have been retrieved? It may help.

When it's in park and you roll it, are there any sounds from the axles, differentials, or anything you hear?

Let me know.

Joe
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Friday, November 19th, 2021 AT 8:13 PM
Tiny
TATU WOODY
  • MEMBER
I pulled it home with a tow bar and the person that road in it said no noise. It was in neutral. The code tripped was p1838 and the torq converter lock up was 0%.
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Friday, November 19th, 2021 AT 9:00 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Okay, the code is specific to the shift motor. There is no movement in the motor when the relay is activated. I feel confident that the transfer case is stuck in neutral.

With this code, you could have a poor connection at the shift motor, a wiring problem, or the shift motor itself may be bad. Since you indicated it shows the 4wd system is responding, I don't think it's a power issue, but we need to check.

First, I need you to check fuse 17 in the under-hood fuse box. Confirm it's good and has power both to and from it.

Here is a link you may find helpful.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If that checks good, I need you to locate the shift motor on the transfer case. I attached a general pic of what it looks like. (see pic 3) Have a helper switch between 4wd and 2wd to see if there is power at either of the two wires (one yellow and one orange).

If you find there is power and there is no movement in the motor, chances are the motor is bad.

Let me know what you find or if you have questions. The 0% on the torque converter lock-up is normal when at idle.

The last pic below shows the fuse to check in the under-hood fuse box.

Let me know,

Joe
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Friday, November 19th, 2021 AT 9:43 PM
Tiny
TATU WOODY
  • MEMBER
Thank you! It was the shift motor. I took it off and it was in neutral. I used pliers to put it in 2 low and it drives fine. Waiting on a new shift motor now. Thanks again!
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Monday, November 22nd, 2021 AT 3:39 PM
Tiny
TATU WOODY
  • MEMBER
I meant 2 high!
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Monday, November 22nd, 2021 AT 3:40 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

That's actually good news. At least it's something you can replace at home without taking half the vehicle apart. LOL

Regardless, let me know if there is anything I can help with. Also, if you have a chance, let me know the outcome.

Take care and feel free to come back anytime in the future.

Joe
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Monday, November 22nd, 2021 AT 7:54 PM
Tiny
TATU WOODY
  • MEMBER
Alright. Thank you! For now, I'm just going to clamp a handle on it and manually shift it in four if I need to.
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Monday, November 22nd, 2021 AT 8:11 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Sounds like a plan. Take care of yourself and have a good Thanksgiving.

Joe
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Monday, November 22nd, 2021 AT 9:24 PM

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