any transmission wizards?

Discussion in 'Transmissions' started by Channeled 91, Aug 2, 2020.

  1. someotherguy

    someotherguy I'm Awesome

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    Throttle valve may be stuck. Sometimes you can pull the cable out as far as it will go and then let it snap back, may take a few tries.

    Did the transmission ever work correctly in this truck since you've owned it? Or was the filter/fluid change an attempt at making it behave? Without knowing the backstory, it sounds like you bought it with known transmission issues - the TV cable being disconnected pretty much spells out that the chances are it's toast.

    Richard
     
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  2. Channeled 91

    Channeled 91 Manic Mechanic

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    The transmission work fine before the fluid and filter change. I did that because I did not know when it was last changed.
     
  3. someotherguy

    someotherguy I'm Awesome

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    How long have you had it and it operated correctly? If it's been a while then somehow the TV cable must have become disconnected.

    As someone mentioned earlier, once you can get it re-connected and adjusted, then you can see if your trans is gonna live or not. Or, if you can find a shop that is honest (difficult) they can deal with whatever is keeping the cable from operating correctly, get it connected and adjusted, and then determine the condition of the trans.

    Richard
     
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  4. Transamco

    Transamco Newbie

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    OK so your pictures show its a 4L60/700R4 trans. TV cable wont cause a loss of drive but if not adjusted correctly can dramatically shorten the life of these units. A couple of thoughts re your issue with the loss of drive after a few miles (i assume its all drive forwards and reverse?) Either you introduced an issue when you replaced the filter and oil - missing / damaged / wrong filter seal up in the pump body where the filter outlet sits, something wrong with the filter itself.... or your transmission has had a major failure the has resulted in a large amount of material being produced, blocking the filter. We see this very often... runs for a short while, suction up through the filter draws in more material the longer it runs, blocking it until the pump starves for oil, and pressure/flow stops. Switch off for a while, some of the material drops away from the filter element, allowing for drive once again for a short period until it blocks again. This normally creates a very audible pump cavitation whine/buzz when the pump loses flow through the filter, but sometimes can be hard to hear in louder vehicles
     
  5. thinger2

    thinger2 I'm Awesome

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    Thats the problem with talking to trans shops about the 4L60
    They either think its an "E" and you are stupid, or you mention the TV cable and they think its a 700R4 and you are stupid.
    A lot of people have never even heard of a 4L60 much less rebuilt one.
    They actually think its some kind of a myth like bigfoot
    So, the guy who told you its a 4L60E is a jabroni
    Dont let that guy near it.
    If they dont know what it is, they sure as shit cant rebuild it.
    There are some major differences between a 700R4 and a 4l60 and a 4L60E
    If it comes down to a rebuild, which I suspect it will. I would take a long hard look at what it takes to put in a built 700R4 before putting any cash into the 4L60.
    But get the TV cable figured out first.
    And just keep in mind that the standard answer from a trans shop is always "You need a rebuild"
    Probably, you do
    Just dont let chimps do the job
     
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  6. letitsnow

    letitsnow I'm Awesome

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    Time to put in a junkyard 4l80e and stand alone controller?
     
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  7. MIHELA

    MIHELA 1-5-6-3-4-2-7-8

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    When is it NOT time for that?
     
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  8. df2x4

    df2x4 Domestics only.

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    When your stock PCM is already capable of controlling the junkyard 4L80E. :lol:

    In this case yes though, he'd have to do something to control it. I've always been curious if a PCM swap would be possible in the earlier trucks to accomplish this? IIRC the 4L80E came out in '91, so there should be some early TBI truck PCM that does transmission control for them right?
     
  9. MIHELA

    MIHELA 1-5-6-3-4-2-7-8

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    Easy enough to get the engine harness and computer, it swaps right in. You still need to do the 3 pin switch in the transfer case which means the case has to come apart and the sector needs to be swapped. Maybe it's not so easy.
     
  10. df2x4

    df2x4 Domestics only.

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    Curious what you're referring to exactly, but the OP's truck is a 2WD I believe so no transfer case issues to deal with. I wonder if it would be possible for him to swap to a different PCM from a 4L80E equipped truck and just run the wiring for the transmission harness and input speed sensor? There could be other differences in the harness, but it would be pretty cool if you could do this swap in an older truck with just a re-pin and a little extra wiring.
     

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