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Tranny ????

Discussion in 'Truck & Equipment Repair' started by B&E snowplowing, Nov 12, 2007.

  1. B&E snowplowing

    B&E snowplowing Senior Member
    Messages: 159

    I have 1995 GMC 2500, it has the 4 speed auto transmission, when it shifts from 1st to 2nd it bangs hard into 2nd gear. It bangs so hard it shakes the WHOLE truck. Every other shift is smooth. Think I need a tranny...Need to know before the snow comes
    Thanks
    Brian
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    If it's an 8 lug 2500 it will have the 4L80E trans. By your description, it sounds like a control problem.. When the 80E's have any kind of fault whether it's a worn valve problem in the valve body or an electrical problem, they revert to full line pressure, which will cause a hard shift.

    Usually it's just a control problem though, like a worn valve or a broken spring in the valve body, or a stuck pressure valve rather than an internal hard part failure that causes this, so a rebuild may not be necessary. A good trans shop can give you a better idea and diagnosis on the health of the trans by test driving it with a scanner connected...
     
  3. T-Trim

    T-Trim Senior Member
    from NE OH
    Messages: 207

    the 4L80E wasn't installed until 96 with OBD 2. It sound like something inside or check your T.V. cable at the TB.
     
  4. R&R Repair

    R&R Repair Junior Member
    Messages: 28

    throttle position sensor or like someone else said the tv cable
     
  5. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Not true...the 4L80's were first used in the SS454 pickups in '91 when the T-400 was phased out....and they dont have a TV cable...they're fully electronic..

    Maybe your thinking of a 4L60E T-Trim, but they were already in production by the '93 model year and didn't use a cable either...fully electronic too..
     
  6. sechracer

    sechracer Senior Member
    Messages: 478

    Sounds like my 97. it has the 460LE tranny in it. It seems to be a common problem with those. After driving down the highway or anything where my speed is 50 or better for a period of time. The truck will shift hard out of first gear. If I turn the truck off for a minute, then restart it, the tranny resets and all is fine. Being that your truck is a 95, it probably wont throw a code. However, the tranny shop told me that it has a valve in it to release the tranny pressure, and it needs a shift kit put in it. They said I could either live with it until the tranny smokes itself (If it ever does) and pay 1300 to fix it. Or pay 1300 now and have it fixed. I opted to wait, and it has been like that for 4 yeas, and still drives fine. tranny fluid is nice and red, filter was changed 2 times, and normal metal on the magnet in the tranny pan. Granted my truck is only a 1500, but it might have the same tranny.
     
  7. B&E snowplowing

    B&E snowplowing Senior Member
    Messages: 159

    Tranny ???

    Thanks for all the help guys, I took it to my Tranny guy.... The thing is screwed and I am now getting it rebuilt. There goes 1800.00

    Nice way to start the season.....Better now though then when I'm out pushing snow I guess
     
  8. terrapro

    terrapro PlowSite Veteran
    from MI
    Messages: 3,878

    you probably should have checked the tranny mount first :cry::dizzy:
     
  9. fuses ??

    I had an experience with a blown fuse that is also the speedo
    and the cruise.
    There may have been other instruments on the same fuse.
    I was so consentrated on the hard shifting I almost didnt
    notice the speedo, etc.

    thought you should check
    tc