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Thread: 1988 Suburban Tranny issues

  1. #1
    Join Date
    Dec 2003
    Location
    Yukon Canada
    Posts
    1,677

    Default 1988 Suburban Tranny issues

    Hi All
    I had to move my nicest Sub the other day. Put in a fresh battery and fired up and purred away.
    It was my Mom and Dads for years. It started life as an Olympic Officials truck at the 1988 Winter Olympics in Calgary.
    I got it back a few years ago still in great condition, but someone took the plaque off the dash that told of it start in life, and the tranny has issues
    It has forward motion,but doesn't really shift like it should.
    No reverse, when it's in reverse you can floor the skinny pedal and the motor doesn't rev up. It sounds like it's under load but nothing happens.
    In Neutral it tries to move forward, but the engine revs up while trying to move.
    Oil doesn't really smell burnt
    Anyone have a direction to point me in or is it in need of a tranny.
    Thanks88 burb 4.jpg
    90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews

  2. #2
    Join Date
    Oct 2001
    Location
    Granby, Missouri, USA
    Posts
    3,104

    Default

    Sounds like a broken band inside the transmission. Unfortunately, it's going to require rebuild or replacement.

    Casey
    1995 K1500 Tahoe 2 door, 6.5LTD, 4L80E, NP241, 3.42's, 285/75R16 BFG K02's; 1997 506 block; Kennedy OPS harness, gauges, Quick Heat plugs, and TD-Max chip; Dtech FSD on FSD Cooler; vacuum pump deleted, HX35 turbo, Turbo Master, 3.5" Kennedy exhaust, F code intake; dual t/stats, HO water pump, Champion radiator; Racor fuel filter

  3. #3
    Join Date
    Dec 2003
    Location
    Yukon Canada
    Posts
    1,677

    Default

    Thanks
    I was hoping it would be something simple,but oh well it is what it is.
    90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews

  4. #4
    Join Date
    Apr 2001
    Location
    Newberg Oregon
    Posts
    12,397

    Default

    I assume it is a 1500 series ???

    If so the tranny is a 700R4

    Gonna need to get that box out and on the bench.
    There are several things that can cause the issues you describe....

    The 700R is not hard to go through.....

    If you want to get an idea.....get the rig in the shop and carefully drop the pan......

    Good bet it has a lot of broken metal pieces in the pan (Shavings)

    Gonna need to come out and apart....

    If the case is not damaged the box can be repaired....

    Keep us posted as to what you decide to do and or find.....

    I'm very curious as to whats broken.......
    Reverse input clutch (Up front just behind the pump) .....Low reverse clutch (At the rear of the box)

    Why is moves in "N" ?????? Parts ground up ??????
    (1) 1995 Suburban 2500 4x4
    (1) 1997 Astro
    (1) 2005 Suburban (Papa Smurf)
    THIS IS BOW TIE COUNTRY

  5. #5
    Join Date
    Dec 2003
    Location
    Yukon Canada
    Posts
    1,677

    Default

    Hi Robyn

    Yes it is a 1500 with the 700R4
    It moves forward just a bit in Neutral,not enough to actually move anywhere. Just enough to give a bit of forward motion like an inch, and doesn't move at all in reverse. It acts like it's working against it's self in reverse as the engine will not rev up with the skinny pedal to the floor.

    Chances are it will not get looked at for a while,My Build a Truck project is ahead of it and with spring it is relegated down the list. If i sell my current shop gas station this year it will be a while before i get a replacement shop built and setup.
    90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews

  6. #6
    Join Date
    Apr 2001
    Location
    Newberg Oregon
    Posts
    12,397

    Default

    Copy

    At any rate....Box needs to come out and apart....
    (1) 1995 Suburban 2500 4x4
    (1) 1997 Astro
    (1) 2005 Suburban (Papa Smurf)
    THIS IS BOW TIE COUNTRY

  7. #7
    Join Date
    Dec 2003
    Location
    Yukon Canada
    Posts
    1,677

    Default

    Peaking of projects...
    I look forward to the return of the Franken Cat.
    90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews

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