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Transmission question on 1991 F-Super Duty

Discussion in 'Ford Trucks' started by Keith_480231, Oct 28, 2007.

  1. Keith_480231

    Keith_480231 Senior Member
    Messages: 389

    I have a 1991 F-Super Duty 3yd dump truck w/ a 7.3 diesel engine. Looking for a trans for the other one lost forward gears. What kinda trans will work on this truck? I have found a 1989 F-250 diesel with a 7.3 diesel. Would this trans work in my dump truck? Or the better question is what will fit in my dump, or does it have to be the exact same one?

    Thanks for any help,
    Keith
     
  2. mike psd

    mike psd PlowSite.com Addict
    from pa
    Messages: 1,028

    i believe its a EOD model i'm guessing you have or might have a PTO to run your dump bed ?
     
  3. Keith_480231

    Keith_480231 Senior Member
    Messages: 389

    no the dump is electricover hydraulic. I do have the overdrive button that I can turn off on the dash.
     
  4. Mudman78

    Mudman78 Senior Member
    from NJ
    Messages: 103

    Since your trans is overdrive, it's an E4OD. It's electronically controlled, so there should be some kind of ECM/interface module on the driver's side firewall about clutch pedal height, but since the 7.3L is not electronically controlled, you can put a 3 speed C6 trans in it's place. Driveshaft length would have to be modified, possibly the shift linkage as well and you'll have to run a vacuum line from the vacuum T on the firewall to the modulator on the trans. If the F250 is a 3 speed, you'll have most of the parts needed except the driveshaft. If you do nothing but local driving, the C6 might be a cheaper alternative, but if you do any highway miles, you're better off spending the $$$ to have the E4OD rebuilt (they have been around for a long time and they can be built pretty bulletproof these days) since the D80 rear probably has 4.56 or 5.13 gears.
     
  5. Keith_480231

    Keith_480231 Senior Member
    Messages: 389

    Thanks guys for the info. I got a guy that gave me a price of $580 to rebuild if I pull it. Does this sound far and anything I should watch out for??? Thanks again Keith:salute:
     
  6. Mudman78

    Mudman78 Senior Member
    from NJ
    Messages: 103

    $580 sounds too cheap. Is he replacing the torque converter and solenoid pack?
     
  7. Keith_480231

    Keith_480231 Senior Member
    Messages: 389

    I don't think so. I actually bought this truck from a buddy of mine and he had a Jasper rebuilt trans put in less than 7500 miles ago. Do you really think that I need to get a new torque converter? I think why this trans lost it's forward gears is because there was never any kind of trans cooler installed. And when I used it to haul topsoil,gravel,etc. I had overheated it.
     
  8. Mudman78

    Mudman78 Senior Member
    from NJ
    Messages: 103

    If the trans only has 7500 miles on it, then the converter should be ok, but make sure you flush it out real good. Heat and vibration from a diesel can weaken the welds inside the converter and it would suck to eat another trans from reusing an old converter.
     
  9. Keith_480231

    Keith_480231 Senior Member
    Messages: 389

    Is the solenoid something that is reliatively easy to change over?
     
  10. Mudman78

    Mudman78 Senior Member
    from NJ
    Messages: 103

    You have to drop the valve body to get to the solenoid pack.