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How to: A4LD Front Seal Info

Discussion in 'Under the Hood' started by mrboyle, August 6, 2002.

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    1. mrboyle

      mrboyle I Drive By Brail Moderator Emeritus

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      I found this the other day and felt it was something everyone that has dealt with the front seal leak should see.

      "A few words about the Ford A4LD transmission:

      This common transmission has problems with pump bushing to converter hub damage that results in front seal "blow-out", short unti life and expensive comebacks. This problem occurs because the factory hole in the housing is not bored on centerline with the crankshaft. The factory corrects centerline by installing an oversize bushing and align-honing it to the crank centerline.

      In service it is necessary to restore the crankshaft to bell housing bushing centerline. Failing to do this results in rapid off center wear of the pump bushing, converter hub damage and ultimatley unit failure.

      Our bell housings are centerline corrected by installing an oversize bushing and align-honing to center. The necessary oil groove is machined into the new bushing to ensure adequate bushing lubercation. This will give you OEM wear characteristics and long unit life.

      While you are servising the transmission be sure to remove the flexplate and inspect the pilot bushing in the back of the crankshaft. They are often found to be broken. If the unit is re-installed with this bushing damaged it will cause front pump damage. It's cheap, replace it!

      The final step in a long living A4LD rebuild is choosing the correct converter. All of this effort to ensure pump bushing centerline standarsd is only of value if the torque converter is also carefully centered when it is assembled. The manufacturer calls for a maximum run-out specification of .012. We feel that a standard of .008 must be maintained to ensure the best possible wear characteristics and balance."

      I left out the name of the company this info came from because I am not trying to advertise for them. I only wanted to provide my fellow X owners with a little more info as to what might be the cause of one of the more common problems we encounter.
       
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    3. SteveVB

      SteveVB Elite Explorer

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      More front seal info

      I copied this and thought I would post it on this thread for future searches same info as above just to reinforce
      Cut and paste follows:
      Torque
      Converter
      Rebuilders
      Association


      A4LD
      Premature Converter Bushing Failure & Seal Blowout
      2.8, 2.9, and 4.0 Engines

      Premature wear or a repeat failure of the converter hub, bellhousing bushing, converter seal and/or pump assembly may be caused by a broken or worn crank shaft pilot sleeve. Located between the flywheel and the crank-shaft, the pilot on the front of the converter is centered on the hole in the sleeve.

      To avoid these comebacks remove the flywheel and visually inspect the spacer on every 2.8, 2.9, and 4.0 engine that may be suspected of having this problem.

      NOTE:
      1. If the original bellhousing bushing is not worn, reuse it.
      2. Converter hub to bellhousing bushing clearance should be .002"-.003"
      3. Converter depth from the front of the pad to front of the bellhousing should be 1 5/8" to 1 3/4"

      If you have repeated front seal blowouts on A4LD's it may not be a problem with the seal or the quality of your work. Your could have a bad bellhousing. The bushing used in the A4LD is finished in place. Because of this the bore that the bushing fits into doesn't need to be in the center of the bellhousing, and in many cases it isn't. When you're working on an A4LD you need to check the bellhousing bushing to see if it's the original factory bushing. If it is, and it's not worn (no more than .003") converter hub to bushing clearance), Don't Replace It! If the bushing needs to be replaced, you need to make sure the replacement bushing will fit in the center of the bellhousing. To do this bolt the torque converter to the flex plate. Turn the engine over and check the runout of the converter hub. Now bolt the bellhousing to the engine. If the Torque converter is contacting one side of the bushing excessively, the bushing is off center and the bellhousing MUST be replaced. However, a slight amount of contact is acceptable. By checking the bellhousing first you can avoid repeated front seal blowout.
       
    4. 1993fordexplode

      1993fordexplode Active Member

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      thank you very much this is the info I have been looking for mine has done exactly what you have just described
       
    5. yaman

      yaman New Member

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      is this one possible root of having the OD light flashing?
       
    6. Eneurb

      Eneurb Active Member

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      A4LD equipped vehicles will not have an O/D light.
       
    7. BrooklynBay

      BrooklynBay Moderator & long time member. Staff Member Moderator Elite Explorer

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      According to an article written by WWW.Atra.Com, they say that a lot of front seal leaks are caused by a low coolant condition in the radiator. The coolant isn't supplying enough surface area around the transmission cooler that is integrated into the radiator. This isn't talking about an external cooler, but the internal one. Here is that article: http://www.atra.com/consumers/bulletins/cb-116.pdf
       
    8. Max458

      Max458 New Member

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      Please...explain
       

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