2003 Lincoln LS V8 Trans Shifting Problems

[twind]

I purchased a 2003 LS v8 with 130k miles and a number of issues... the largest being shifting issues. Was told originally it needed the solenoid pack replaced (had codes for all three shift solenoids). I started by replacing the solenoid pack, but it did not fix the problem. I then sent out the PCM to be tested/repaired and it tested okay. The company that tested the pcm noted to looked for bad grounds. I then found the o2 sensor wires were cut and the 4 wires were touching - causing a bad ground (cats were stolen and previous owner had repaired by installing a pipe where the cats were originally w/o replacing o2 sensors). I then made sure the wires could not touch, but still do not have o2 sensors (all circuits are open for sensors and heaters). This got rid of the codes for bad solenoids, but the trans still shifted very poorly. I then replaced the entire valve body with an "upgraded" sonnax reman valve body. This did not make any difference to the shifting.

The 1-2 shift is harsh, 2-3 shift hits hard then the car seems to defuel for a split second then take off again, the 3-4 shift is slow and has a bit of shudder, 4-5 has no issues.

The car obviously has codes on for the o2 sensors/cats missing, but no other codes on the pcm. I was planning to replace these once the shifting issues were resolved, but is it possible that these open circuits could be causing poor shifting? The only other common problem I have read about for these transmissions is the servo bores wearing out, but I thought that the worn out bores would result in losing gears?

Any other possible causes? I have read that even the coil packs could cause poor shifting, but this seems extreme to be caused by any type of misfire.

 

[Layla11242]

Anything ever come of this?

 

[Buckie]

Anything ever come of this?

It could be several diff things with erratic shifting. My 06 did the same thing. I did not catch mine until it was to late and had to rebuild it to the tune of $2200. If your LS is doing this start at the simplest and work to the hardest and worse thing- a rebuild. Start at the coils to see if the valve covers are leaking oil into the plug holes shorting out the coils, make sure the coils are good, go through and check wires and connectors for obvious corrosion and clean to make sure everythings getting great connection, after that id take my throttle body apart to see if those magnets have came loose inside the silver housing hitting the electric motor, if you have electronic throttle check your signal from pedal to throttle body to make sure they are communicating correctly. Check fuel pressure, remember you have a jet pump and fuel pump. There is shift springs inside the tranny that can get weak overtime and can cause this. Check the servo bores and if they're wore out or not i would havem drilled and put brass sleeves in them because they can wear and cause problems. If its still not shifting correctly after the servos and springs are good then have the ECU and modules checked, if the ECU and modulels are good
then it could be a short somewhere in the wiring harness. If theres no short then rebuild the transmission. I know this is alot of work but i have researched an researched and researched about all these being issues. Good luck

 

[Layla11242]

It could be several diff things with erratic shifting. My 06 did the same thing. I did not catch mine until it was to late and had to rebuild it to the tune of $2200. If your LS is doing this start at the simplest and work to the hardest and worse thing- a rebuild. Start at the coils to see if the valve covers are leaking oil into the plug holes shorting out the coils, make sure the coils are good, go through and check wires and connectors for obvious corrosion and clean to make sure everythings getting great connection, after that id take my throttle body apart to see if those magnets have came loose inside the silver housing hitting the electric motor, if you have electronic throttle check your signal from pedal to throttle body to make sure they are communicating correctly. Check fuel pressure, remember you have a jet pump and fuel pump. There is shift springs inside the tranny that can get weak overtime and can cause this. Check the servo bores and if they're wore out or not i would havem drilled and put brass sleeves in them because they can wear and cause problems. If its still not shifting correctly after the servos and springs are good then have the ECU and modules checked, if the ECU and modulels are good
then it could be a short somewhere in the wiring harness. If theres no short then rebuild the transmission. I know this is alot of work but i have researched an researched and researched about all these being issues. Good luck

I appreciate the response and info. I have suspicion that it's the wiring harness, as I just had the tranny rebuilt 25k miles ago. I've had the ecu repaired and then replaced too each "fix" of the ecu makes the shifting act very different.

 

[Buckie]

I appreciate the response and info. I have suspicion that it's the wiring harness, as I just had the tranny rebuilt 25k miles ago. I've had the ecu repaired and then replaced too each "fix" of the ecu makes the shifting act very different.

You're welcome. I Googled myself cross eyed lol trying to find out what was wrong with mine and ran across all those issues. I really believe the magnets inside that round silver cylinder on the throttlebody caused my problems. They had been coming unglued and spinning around in there for a minute. They had been hitting that electric motor that turns forward and backwards causing it to bind itself off. The only way to tell is to take it apart. I didn't find it until after i had to rebuild the transmission. I did 2 things to my 06 i had my trans rebuilt and i replaced that silver thing on the throttle body and i haven't had anymore shifting problems. It coulda just been a coincidence but the LS is a weird car when it comes to its electronics, you can have a headlight out and it might cause the radio to quit playing lmao! I hope you find your problem.

 

[lsguy77]

I have an 03 and It shifted hard from 1st to 2nd, and 2nd to 3rd. I tried flashing my pcm, a new tranny, a new torque converter, new solenoids, I tried everything, but what fixed it for me was I got a new pcm, set it to the car, and it worked beautifully!

 

[Layla11242]

Just a quick update, after repairing PCM twice and getting a new PCM from Flagship 1 and replacing the solenoid pack, issue persists. The reputable tranny shop thinks its a chip in the PCM. He's getting voltage to the solenoids which means its not the harness.