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  • CD4E Rebuild

    This information is curtesy of ProbeTalk member J.O

    Ford CD4E Transaxle Rebuild
    12/21/02 thru 2/2/03

    I have just completed rebuilding a CD4E automatic transaxle in my son’s 1994 Ford Probe. The car is a 2.0L I-4. The vehicle had 91K miles at time of transaxle failure.

    Symptoms:
    Vehicle would not move in reverse when hot.
    Transaxle would slip excessively in Drive.
    O/D Indicator Lamp was flashing

    History:
    O/D Indicator lamp had been flashing for months prior to failure. My son had changed fluid last summer in hopes that this would cure the problem. Fluid removed at that time was burned and contained lots of particles suspending in the oil. O/D lamp continued to flash. By mid December 02, the car could not move in reverse under its own power. when hot. The engine would rev but the car would not move. About this time, while driving, the transaxle would slip excessively in Drive. The first and second gear shifts were very harsh. Once in drive (3rd gear), the engine would rev but vehicle speed would decrease. It was at this point that my son parked the car.
    Eric
    96 Miata M
    We're all still learning...


  • #2
    Transaxle Removal:
    The first thing I did was purchase a factory Ford Shop Manual off e-bay.
    Follow the manual for step by step instructions to remove the transaxle. The only problem encountered during remove was gaining access to the torque converter/flexplate nuts. These four nuts are accessed through the starter hole. There is a small plastic plug that slips into the hole surrounding the starter opening. You need to remove this small plastic ”plug” to get access. Use an inspection mirror to see it. I messed around for about 4 hours before I discovered a solution. The plug slips toward the center of the start hole to remove it.
    I purchased a set of transmission plugs from Mac when I did my last transaxle. Lisle also sells a set for around $15. Make sure you install a plug in one of the halfshaft holes in the transaxle case before you remove the opposite halfshaft. This keeps the differential side gears from shifting around.

    Transaxle Teardown:
    Nothing out of the ordinary to report here. I set up a 4X8 sheet of plywood on sawhorses so that as I removed pieces from the transaxle, I could place them in order for reassembly. Make sure to follow the procedure outlined in the service manual. Watch out for thrust bearings since they like to stick to the mating parts during removal. I cleaned everything in cleaning solvent as I tore the transaxle apart. As you break the transaxle down, take notice of anything that looks burned or discolored by heat.
    Eric
    96 Miata M
    We're all still learning...

    Comment


    • #3
      Repair Parts:
      I purchased the following parts during the rebuild process. I think this should be the standard rebuild list if your car exhibits any of the problems listed above.

      Torque Converter
      Replace it since it has been filled with contaminated oil and particles suspended in the oil.

      Forward Drum
      These drums have a bad habit of cracking their welds as they get old. Excessive pump pressures cause weld failures. In this transaxle, the bushings were shot and the drum had dropped on the oil pump pedestal. This drum was a goner.

      Reverse Drum
      Bushings were destroyed and the drum was damaged.

      Reverse Hub
      Bushing damaged and mating surface to reverse drum was grooved.

      Solenoid Pack
      Ford redesigned solenoid pack for late model Contours and Escapes. New design will retrofit into early models and fix some of the problems. Solenoids can get plugged with contaminants that are suspended and circulated through the transaxle fluid. A local builder says to always change them, it’s cheap insurance. Look for a beige connector instead of black. Black connector is the old version.

      MLP Sensor
      Another component that has been redesigned over time. A source of problems when exposed to heat. Another cheap insurance item although it can be replaced after rebuild if it throws a code.

      Transaxle Oil Pump
      Another redesigned component. Make sure you specify you want the “new design” pump. Ford revised the pump because the pre 1997 model had a tendency to blow out its internal gasket. If your forward drum bushings fail and the drum drops on the oil pump pedestal the pump pedestal will get damaged and the edges of the sealing surfaces become razor sharp. Be careful.

      Master Overhaul Kit
      I purchased a Transgo Master Rebuild kit with steels and new friction materials.

      Filter
      The fluid filter was not included in the master kit. It must be purchased separately.

      Band
      I replaced the band with the new designed band. It is wider than the original that came out of the transaxle. The narrow band is no longer available.
      Eric
      96 Miata M
      We're all still learning...

      Comment


      • #4
        Shift Kit
        I purchased a Transgo Shift Kit. This is one of those optional things you can do. The local guy I talked to said they install this kit every time they do a CD4E. It makes changes to the valve body. If you chose to use this kit, make sure you follow the instructions to the absolute letter of the law. Nothing more. Nothing less. There are also instructions for transaxle assembly that are very helpful. The kit was on $30 so it is worth the investment in my opinion.

        The total cost of parts for this rebuild was right at $1000. Just remember, the cheapest place I found was $2250 for a rebuild. You may be able to find a unit in a salvage yard but I could only find one and it was $1250. You also really don’t get much of a warranty with a salvage yard unit.
        Eric
        96 Miata M
        We're all still learning...

        Comment


        • #5
          Rebuilding The Components
          Just follow the shop manual and get everything clean.
          I cleaned everything during teardown just to get most of the oil off all the pieces. Make sure you clean every piece as you break down your components. I washed them once in solvent and then again in clean solvent just prior to reassembly. I also used compressed air to blow everything clean after solvent washing.

          The toughest part is removing the springs from the drum assemblies. I made my own tools from PVC pipe. I found a scrap piece of PVC that was the diameter of the springs. I used a long bolt and a couple of steel bars to act as a spring compressor. It is more difficult this way but it can be done. It beat buying a $250 spring compressor.

          Another difficult part is installing the pistons with new seals. The shop manual says to use special seal protectors to install the pistons. I just used STP or vasoline to lube the seals. Set them on top of their bores. While applying light downward pressure, use a .010 feeler gauge and start working your way around the piston. Just poke the seal with the feeler gauge. The first time is tough but once you get the hang of it, it goes pretty easy. Above all, keep the thing lubed, the slicker, the better. If not, the seals will tear when you drag the feeler gauge over them. Try to poke down on the seal, not drag around the piston bore.

          Note, make sure you presoak your friction materials in ATF at least 1 hour before you install them. When I get the rebuild kit open, I pull all my friction materials out and put them I a pan of ATF. They soak a minimum of 24 hours. This prevents excessive wear at startup when there is a diminished fluid supply from the pump.

          Just keep following the manual step by step. If you get frustrated, step outside for a while. This thing is really tedious and will drive you nuts. Just don’t get in a hurry and you will be fine.

          Once you get a component reassembled, place it in a plastic bag to keep dust and dirt off the parts.
          Eric
          96 Miata M
          We're all still learning...

          Comment


          • #6
            Rebuilding the Valve Body
            The VB is the brains of your transaxle. It is also the most complex component in the transaxle. Don’t be intimated by its complexity. Just remember to go slow and be careful. It took me about 6 hours to get the VB torn apart. About 2 hours to reassemble.

            There are two ways to address a Valve body during an overhaul.
            Complete disassembly and cleaning
            Thorough cleaning only

            I completely disassembled the valve body since I needed to install the shift kit. The shift kit requires you to drill some additional holes through passages in the VB. I wanted to make sure I got all the metal shaving from the drilling process removed before I reassembled the VB.
            During teardown of the VB, it is important that you do not mix up any of the parts. You must keep all the spools and springs in there proper places or else you are asking for a disaster of epic proportions. I went and bought a large metal baking pan and lined it with a piece of a fluffy bath towel. This way, as you pull the pieces out, you can lay them in the pan and they will not roll around.
            Disassemble the entire VB. Get all the spools and springs out. You will probably have trouble getting some of the retaining plugs out of the VB. Just take your time and keep working the valves with a pick or small screwdriver. Don’t force anything. This process will drive you nuts but it must be done to make sure no particles keep the spools from sliding in there respective bores.

            Install the Shift Kit. The instructions are clear and straight forward. Follow the directions exactly as stated. You will be drilling some new passages, installing new springs, and installing a new pressure regulator valve. Once again, make sure you clean everything and blow off excess solvent with compressed air.

            Reassemble the valve body by installing all the spools and springs back into their respective locations. If the retainer plugs give you trouble, you can sand them down with 600 grit sandpaper. Just take off enough so that they slide in easy.

            If you chose not to install a shift kit, just clean the entire valve body assembly in solvent and blow dry. Use a screwdriver or a dental pick to make sure all spools move freely within their bores.

            Reassemble the entire VB and place it in a plastic bag for reinstallation.
            Eric
            96 Miata M
            We're all still learning...

            Comment


            • #7
              Transaxle Assembly
              As I have stated numerous times before, follow the instruction manual. It is very thorough and complete. Use vasoline to hold thrust washer and bearings in place. Since I did not disassemble the differential side gears, you can eliminate the steps of checking differential clearances. Just reuse the shims that were in your transaxle. Make sure you install a new seal on the filter. The filter does not come with a new seal attached. It is a component of the master kit.
              Make sure you air check the transaxle prior to installing the converter case cover and valve body. There are instruction in the rebuild master kit that tell you where to apply compressed air. Never exceed 40 PSI when testing or you may blow out a piston seal.
              If you have things installed properly, you will hear a thump as each piston engages. If you hear a hissing or popping noise, most likely you damaged a piston seal and you need to go back and fix it.

              Transaxle Installation
              Put a quart of ATF in the torque converter. Install the converter in the transaxle just prior to going back into the vehicle. Note, the converter must be fully engaged on the oil pump drive shaft and the converter support shaft. Spin the converter and apply pressure. You’ll know when it engages. It will just “drop” into place.

              Just follow the manual. It is just a reverse of the removal process. Torque everything to required settings. The hardest part is getting the converter studs to line up with the flexplate holes. If the converter has been installed correctly, the studs will stick through the flexplate just enough to start the nuts. Tightening the nuts will pull the converter against the flexplate surface.

              Road Test
              After the car has been filled with ATF, take it out on a test drive. Start out simply by just going around the block. If the transaxle has been assembled properly, it should shift smoothly. If you detect any slipping on this initial run, get back to the garage as quickly as possible. You do not want to risk damage to new components.
              If the drive around the block goes successfully, head out on the road for a minimum of 30 miles. Drive at speed below 40 MPH with the overdrive disengaged. If all feels good, take it up to 55MPH and engage the overdrive. Drive it and make sure it is shifting properly. Keep an eye on the O/D indicator lamp. If it starts blinking, head for home.
              Eric
              96 Miata M
              We're all still learning...

              Comment


              • #8
                Additional Notes[list=1][*]The initial rebuilt on my son’s CD4E failed at about 30 miles. The O/D indicator lamp blinked on after 30 miles. We had a local shop hook up a Snap-On scanner and pulled up a Code 628, Excessive Converter Clutch Slippage. Took the car back home and removed the transaxle. Removed the torque converter, returned it to the supplier, exchanged for another unit, reinstalled in transaxle and reinstalled transaxle in vehicle.[*]The second attempt was successful and has been operating now for 2 weeks with no malfunction indications.[*]I added a transmission cooler to the vehicle. I purchased a small cooler and mounted it to the front of the A/C condenser coil. A lot of internet traffic suggests that heat shortens the life of the CD4E. The cooler kit was $40. Cheap insurance. [*]I added and inline oil filter. Since the oil filter is located deep inside the transaxle case, it cannot be changed without complete teardown of the transaxle. I purchased a small canister oil filter from the transmission parts shop that is installed on the outlet pressure port of the transaxle. Now, my son can change 5 to 6 quarts of fluid and a filter every 10K miles or once a year. This should help prolong the transaxle’s life. If you are so inclined, you can cut the old filter open and inspect the filter media for metal particles. This will let you know of any internal problems before they manifest themselves into a major disaster.[*]Notice it took me 5 weeks to get the car back on the road. Luckily our family was able to adjust its vehicles and he was still able to drive to work. If your time has a price, it will amount to about $1200 to $1500. That is the difference between tackling the job and hiring it done.[*]I am by no means a qualified mechanic. I’m an Aerospace Engineer by day and a Shadetree Mechanic when time permits. I made a few mistakes and learned a lot along the way. And yes, I would do another one if the need arises. My wife’s 2002 For Escape has a CD4E transaxle so I’m ready when it decides to give up.[/list=1]
                Eric
                96 Miata M
                We're all still learning...

                Comment

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