Transmission slipping? hesitation?

Discussion in '3rd Gen 1997-2002 2.0L SOHC' started by Skeets, Apr 10, 2011.


  1. ethangsmith

    ethangsmith FEOA Member

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    I wonder why there are so many pressure issues with this transmission. It's almost as if Ford has the PCM's signal set wrong that it chronically runs the pressures too low. Either that or the internal seals really suck and there's tons of leaks that develop.
  2. bent_rod

    bent_rod FEOA Donator

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    Back in the 90s when the Escorts were popular with the rental places I drove many new ones and the automatic transmissions worked good. The first owner of my 2000SE and the woman that was the first owner of the ZX2 that the guy next door has, both had very good luck with the cars until after the warranty ended.
    Apparently they develop seal problems after some wear takes place brought about by some design short cummings. To fix the transmission I think a complete rebuild would be needed. At least the valve body needs to be rebuild.
    I have the TransGo shift rebuild kit for my transmission, just have not had the time to do the job. The EPC pressure riser mod keeps the transmission from slipping, but it is just a band-aid. http://www.transmissionpartsusa.com/FOR ... 033931.htm

    Below are some notes about problems with the transmission. I collected them from different sources but most came off of the shift kit instruction sheet.


    The Ford 4EAT-F is a 4 speed electronically controlled automatic transaxle with lock up. Introduced in 1990, by Mazda Motors, the F4A-EL or 4EAT-F was classified as a light duty transmission based on the Mazda GF4A-EL or 4EAT-G used in the Ford Probe and Mazda 626. The 4EAT-F has 120 FT-LBS torque capacity in its stock configuration. The original 4EAT-F was introduced by Ford Motor Company and used three electronic shift solenoids, one lockup solenoid and was shifted via a kick down cable. The kick down cable was removed in 1997 and replaced with an electronic pressure control or EPC solenoid and the transaxle was renamed the F4A-III. Over the years the 4EAT-F has manifested many flaws ranging from the lack of torque capacity to the front seal being forced out of its bore due to line pressure spikes.

    On to the problems.

    The first failure in the F4A-III starts long before it ever manifests itself. This failure is the most overlooked and often the most detrimental problem the transaxle has. It in fact, is a result of cheap engineering by the factory. The cause of failure is the thin aluminum thrust washer found inside the torque converter. As the washer wears it deposits fine aluminum particles in the transmission fluid and they are carried throughout the transmission. These particles are moved throughout the transmission often under pressure and start to wear out critical components. The small aluminum particles acting like a sandblaster attack the soft copper bushings, the teflon sealing rings and the rubber seals and gaskets causing internal leaks and loss of line pressure throughout the transaxle. The aluminum particles also degrade the the finish of the accumulator and valve body bores and cause shift feel problems and complaints. Lastly it is worth to note that the aluminum particles will mix with the carbon that is found in transmission fluid and creates what i will call Muck. This muck will be deposited throughout the transmission and eventually ends up in the valve body and accumulator and also the transaxle cooler and line assemblies. Note: when ever servicing, rebuilding a 4EAT-F or F4A-III transaxle it is important to always replace the stock ford torque converter with an heavy duty unit featuring a Torrington bearing, instead of a thrust washer, such as the ones sold by ZXRacing in the dealer section.

    It is also important to flush the cooler lines and transaxle cooler assembly with a good cooler flush such as ATP's Transmission cooler line flush in can and dry with compressed air. Failure to clean the cooler and replace the converter will result in re-contamination of the new or rebuilt transmission.

    Another common problem with the F4A-III is the shift shudder when shifting into 2nd gear. The shudder in second gear is a two part problem. The first problem is the quality and material of the bands used both at the factory and by rebuilders. OEM and common aftermarket bands are made of the standard tan materials and are prone to glazing. Once a band starts to glaze its surface hardens and it loses its holding ability and starts to slip this slip is what causes the shudder and shock felt in the 1-2 shift on most higher mileage F4A-III. The only way to prevent band glazing and 1-2 shift shudder is to use a Dakin (charcoal colored) 2-4 band. The second problem is the condition of the 2-4 band drum surface, this surface when in contact with a glazed band and high heat can burn and sometimes even warp the drum. Caution should be taken when rebuilding to check the surface for warpage and also to recondition it with a peice of 180 grit sand paper to remove any glazing and promote holding power.

    The reverse bang or harsh reverse engagement, felt especially when going backwards up a hill, has and need not be an issue. There is a very simple fix that i will detail later.

    A good thing to remember is the .010ths per friction rule for racing and heavy duty transaxles. At the factory the clutch pack clearances are set on the loose side generally allowing .020ths per friction to allow for soft comfortable shifts that your grandmother would like. The increased clutch pack clearances create longer shift times and and increased heat on the clutches. A tighter clutch pack clearance provides a firmer and more crisp shift with less heat generation.

    Torque capacity itself is a problem with this transmission as stated before the transmission has a torque capacity of only 120 FT-LBS. This need not be the case there are several upgrade parts packages available that can increase the torque capacity of this transmission by 60%.

    The F4A-III consists of five clutch packs, one band and two one way clutches. We will detail each clutch and its usage.

    The Forward clutch consists of 3 frictions and 3 steels is applied in all forward gears and takes the most strain. When selected 33% of the engines torque is applied to each friction.

    Low Reverse clutch consists of 4 frictions and 4 steels and is applied only and drive low and reverse. When selected 25% of the engines torque is applied to each friction.

    The 3-4 clutch or Overdrive clutch consists of 3 frictions and 3 steels and is applied only in overdrive or drive four. When selected 33% of the engines torque is applied to each friction. This clutch is prone to failure due to heat and lack of friction area and should be upgraded to the 5 friction TorquePaK setup. This pack increases the torque capacity of the 3-4 clutch pack by 60%. With a 5 clutch pack setup 20% of the engines torque is applied to each clutch.

    The Reverse clutch consists of 2 frictions and 2 steels and is applied only in reverse. When selected 50% of the engines torque is applied to each friction.

    The Coast Clutch consists of 2 frictions and 2 steels and is only applied during coasting or periods of deceleration. When selected 50% of the engines torque is applied to each friction.

    The 2-4 Band is applied in second and 4th gear. When second gear is selected the 2-4 band is applied and holds 100% of the engines torque. The when fourth or overdrive is selected the transmission is already as the 3-4 clutch applied and all that is needed is the application of the 2-4 band.


    Another weak link in the 4EAT-F is the input sprag or one way roller clutch. The sprag has been know to explode literally and embed metal throughout the transmission. A heavy duty sprag is available for the 4EAT-F that will prevent the input clutch failure and increase torque capacity.

    Common systems or problems and their fixes
    A common problem with the 4EAT-F has been the valve in the pump sticking. Delayed engagements hot, especially reverse, neutrals at stops, 3rd gear starts until throttle is added, high clutch failure, and possible pump damage are all results of a malfunctioning pump valve. Be sure to closely inspect the pump body for metal transfer between the outer gear and the pump gear bore wall. Remember that all the oil, and metal particles, that are discharged from the pump will be routed to the pump valve. To greatly reduce valve sticking complaints and failures install a redesigned Pump Valve. This valve is improved over the factory design by having numerous cleaning grooves along the length of the valve. Sticking valve complaints are greatly reduced with the redesigned valve.

    A complaint of slips on start-off in drive, may be worse hot, but works OK in manual second and low is most commonly due to a cracked forward drum housing. The crack is most easily seen from the back, bottom, side of the drum. If the vehicle is driven in drive and allowed to slip for any length of time the forward clutches will burn out. A cracked housing can also create 3-4 bind, burnt band, burnt coast clutch and/or chatter on 1-2 shift, depending how badly the housing is cracked.
  3. bent_rod

    bent_rod FEOA Donator

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    This link will show how to install the new valve and spring: http://www.feoa.net/modules.php?name=Fo ... ic&t=61690
    When installing the LubeGuard Red don't overfill the transmission. If needed drain out to adjust level, check level after transmission is up to operating temperature. I did a complete drain out and refill with new fluid, filter and a bottle of LubeGuard Red.
  4. ethangsmith

    ethangsmith FEOA Member

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    I have a fear of the valve sticking in the transmission. Hopefully it won't. I'll be interested to see if the new valve and spring make a difference. Has it actually succeeded in fixing any cars with issues so far????
  5. bent_rod

    bent_rod FEOA Donator

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    The old valve in my transmission pulled out with only a little help. It had no sign of any metal debris stuck in the valve. If you do find a lot of metal chunks stuck in the valve I think the transmission is ready for a major rebuild.
  6. ethangsmith

    ethangsmith FEOA Member

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    What is the best way to remove a sticking valve? I saw one guy used a bent screwdriver tip. Would a small pick work too?
  7. throbas

    throbas New Member

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    in know it may be in the wrong section, but would this work for my zx2, this happened all the time in my old se and this ones doing it too
  8. ethangsmith

    ethangsmith FEOA Member

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    Yes! I'm fighting with this on my new 2000 ZX2. The transmissions on the sedans, wagons, and ZX2s are the same.
  9. bent_rod

    bent_rod FEOA Donator

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    I think you are over planning this job. Your car only has 35K on it right, hopefully the transmission is not a basket case, the valve should all most fall out. I think if my transmission fluid had been warm when I unscrewed the plug the spool valve would have dropped out without any help. As I recall all I had to use was an old dental pick to pull it down.
    Now if you want to read a horror story check this out: http://www.grandprixforums.net/f4eat-tr ... 17051.html
  10. ethangsmith

    ethangsmith FEOA Member

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    Good lord. It IS true these transmission are pretty much unrebuildable junk.
  11. bent_rod

    bent_rod FEOA Donator

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    Did you read the posting near the end of the thread that said he put a ball in the valve assembly that was too large? After installing the correct ball the transmission has been working good for the last 10k miles.
    It does illustrate how careful one needs to be when rebuilding the transmission. It only takes one small screw up to trash the rebuild job.
  12. ethangsmith

    ethangsmith FEOA Member

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    Yep. Amazing that something that small with burn out so many parts so quickly. Other than installing the pump valve I ordered, I will leave all other repairs to a professional!
  13. throbas

    throbas New Member

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    man, another problem solved by this forum, serious thanks a bunch guys! :D
  14. ethangsmith

    ethangsmith FEOA Member

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    I may have found another offshoot of this transmission issue. I figured out after a bit of driving today that the engine is surging and my power delivery is uneven. I think when the engine is lacking power, it makes the shift point soft and incorrect. Now I have to find the root of the surging issue too. With only 35K miles, I figure there's a good chance it needs plug wires and a few tanks of injector cleaner. I just put a new air filter in and made sure the throttle body is clean. I suppose I should also put a new PCV valve in as well.
  15. ethangsmith

    ethangsmith FEOA Member

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    Nevermind. Seems like the surging IS in fact transmission slippage. I cleaned the MAF sensor, checked for vacuum leaks, replaced the air filter, cleaned the throttle body, checked the PCV valve and hose, and checked for loose electrical connections this afternoon. After filling the fuel tank with fresh fuel and injector cleaner, I took it out for a nice long run. It has become much more evident that once the transmission gets completely warmed up, the shifts become way too early and slip badly (The 1-2 shift is barely complete before the 2-3 shift occurs). Once the converter locks in overdrive, if you try to go up any type of hill and give it more throttle, the converter seems to start shuddering. I'm assuming all these symptoms are from low line pressure???? I'm really wondering if the Transgo spring and valve are going to help this.............
  16. bent_rod

    bent_rod FEOA Donator

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    Well anyway, the things you did plus a new set of autolite platinums and wires is always good when you first get a used car.
    The pressure regulator valve kit needs to be install on all the F4EAT transmissions, a low cost item that eliminates a known problem.
    After that install the 10 ohm resistor in the EPC line. Do it, it works.
    Then if it is not to your liking get the TransGo Shift Kit installed by a shop. Most likely by installing only the parts in the kit that go into the valve body you will have a very good operating transmission. The transmission will not need to be removed from the car to do that.
    http://www.transmissionpartsusa.com/FOR ... 033931.htm

    Also: Get the Lubegard red in, it made my transmission work much better.
  17. ethangsmith

    ethangsmith FEOA Member

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    Yea. I'm developing a plan of attack. I found that a reman. transmission will run me around $2000 with a good torque converter. I may have a local transmission shop (with a great reputation) rebuild and install a full Transgo shift kit on the transmission. Still assessing options. I will continue to update the thread as I make repairs. I'm hoping the pressure valve is the magic fix, but I'm not holding my breath.
  18. bent_rod

    bent_rod FEOA Donator

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    Sounds like a plan, good luck.
  19. ethangsmith

    ethangsmith FEOA Member

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    New pressure valve and spring are in. Seems to shift a little better around town. Still seems mushy as it warms up though. The old valve fell out and there was basically no dirt in the bore. However, I did notice some light scuffing all around the valve, which would indicate it may have been sticking intermittently. I have people coming to look at the car tonight so hopefully this did in fact fix it. It did seem like there was a good improvement so far!
  20. limerence

    limerence New Member

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    hey guys,

    got a 97 se wagon with 140k miles on it where the tranny is starting to give me issues. if the car gets warmed up for awhile the tranny runs ok. but if its not warmed up quite a bit, from first to second, i get a strong rev as if it in neutral.

    took it out for a quick trip and now noticed it kicked into gear after first which it did not before. before it was smoother even though it finally got into gear late.

    lubegard would help?

    tx.
    -john

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