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94 to 98 Lincoln Mark VIII Transmission Swap

The Re-pin Alternative

4R70W

Since I really could not find a detailed "How To" for the swap, I decided the easiest way for me to know it would be right and simple. So I decided to pull everything electronic out of the 94 and put it into the 98 since the issue I had with the 94 Transmission was mechanical.

....Click images for an EXTREME CLOSEUP....
Do You Have A  98 Transmission?
Look on the top of the
transmission for a casting year.
Look for an orange sticker.
This informs the technician that the transmission
does not have the accumulator upgrade.
This Transmission did come out of a 98 LSC.
 

Tools needed

  • Torque Wrench
  • Small Flat Head Screw Driver
  • Socket Set Metric & Standard
  • Box End Wrenches or 2 Box End Wrenches
  • Impact Gun
  • Adjustable Torque Drill
  • Extendable Magnet
  • Breaker Bar
  • Zip ties
  • Permatex
  • Roll Of Shop Towels

Set Up & Pan Removal

  1. Clean your workspace                            
  2. Drain both transmissions
  3. Remove the harness from both transmissions
  4. Remove the MLPS (so you do not damage it)
  5. Flip the transmissions over (so you can access the pan)
  6. Remove the pan bolts
  7. Study the two Transmissions (so you know what has to be done)

     '94 Gen 1

     '98 Gen 2


Solenoid removal

  1. Remove the unplug all of the solenoids on the 94 and remove the circuit board from the 98
  2. Unbolt the shift solenoids and TCC solenoid
  3. Remove the solenoids. Gently pry the solenoids up or just use your hand
    • * Note: there is a grounding clip on the 94 TCC solenoid bolt. You will need it. The 98 does not have one
  4. Remove what I believe to be the Trans Temp sensor
    • Gently pry it off the plate. If you break the clip don’t freak out. It’s no big deal, I broke the clip too
 


Remove Valve Body

  1. Remove the gear selector switch tensioner
    • Loosen the Trans pressure solenoid clip first and set it and the bolt aside (but keep them together)
  2. Loosen the rest of the bolts on the Valve Body.
    • Loosen the 10mm Bolts on the 98 Transmission (Just the bolts with the washers)
      • You do not have to remove the plate on the 98 Transmission.
    • Remove the valve body in one piece

    • Pull the plate off of the 94 Valve body 


Transmission Line Pressure Solenoid

Remember you already removed the Retaining clip when you removed the valve body
  1. Remove the gear selector nut using a wrench on each end of the selector arm to loosen the nut and remove
  2. Pull the pin up and out to release the arm. 
  3. Slide it back out of the way (You do not have to remove it)
  4. Then slowly work the solenoid out.
You can use the 98 Trans Pressure Solenoid, you just have to solder the wires to it. I choose to swap everything.  


Wiring Harness

  1. Gently remove the plug from the bottom side of both Transmissions.
  2. Pry the plugs out with a flat tip screwdriver
  3. Gently remove the plug from the bottom side of both Transmissions.
  4. Install the Gen1 harness into the 98 transmission


Reassembly

  1. Reinstall the Transmission Line Pressure Solenoid
  2. Install the Gear Selector arm and Pin
    1. Install the nut onto the Gear Selector Arm
    2. Install the Pin and tighten it
  3. Install Valve Body
    • Torque the bolts to 10-12 lbs starting from the center outward
    • Use your judgment and don’t strip the thread
  4. Install the retaining clip for the Transmission Pressure Solenoid
  5. Install the Gear Selector Tensioner
  6. Make sure the Gear Selector Valve is in the correct slot
  7. Install Shift Solenoids and TCC Solenoid
    Don’t forget the install the Grounding Clip for the TCC from the 94
  8. Install the Temp Sensor.
    If you broke the clip, Zip tie it like I did
  9. Plug all the wires back in
  10. Install filter
  11. Install your pan and gasket
    Ensure that it's very clean prior to reinstallation!
  12. Torque your pan bolts
  13. Flip the transmission overInstall the MLPS and the 94 Exterior Harness
    Make sure you line up the MLPS properly
  14.  Switch out the Speed Sensor
  15.  PUT IT ALL BACK TOGETHER

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