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Thread: No second gear on automatic upshift

  1. #1
    Join Date
    Mar 2006
    Location
    Harrah, Oklahoma
    Posts
    89

    Default No second gear on automatic upshift

    Finally got the whole rig back together, been driving a couple of days. Took a longer drive, about 80 miles and on the way it started missing second gear on upshifting. Not throwing any codes, just shifts from first to third then on up. I can manually down shift from 4 to 3 and then on down to 2 and when slow enough to 1. Tranny only has about 7k miles on it since major rebuild by super reputable mechanic, has worked really nice, solid, firm, quick upshifts every time and not violent either. No hotrodding, seriously. Have been told to check the solenoids but the ATSG manual for this transmission says all failures for missing second gear are mechanical, but second gear is still there so it must be electronic? Right? What advice do you folk have to offer?
    95 GMC C2500, 449,000 miles, 4L80E w/ 4.11, 4 inch exhaust, gauges, OPS relay mod, Cold start & Fast Idle controls, 18-1, PMD cooler, coolant updates, cam gear drive, Chinese HX35W clone., Kennedy Max Effort chip

  2. #2
    AKMark is offline Building another 6.2L powered vehicle
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    Dec 2006
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    Default

    With that low of mileage since rebuild, I would talk to the rebuilder.
    05 2500HD CC LB LLY, 4x4, 3.73s 235/85R16's, webasto cab heater, to keep it warm.
    03 Buick Rendezvous - When you average over 80 miles per day driving around, you need one of these.
    85 K-5, 6.2, SM465, Rockwell T221, 1 tons, 36's. More goodies to be installed as time and money allows.
    82 K20, 6.2, SM465, NP208, stock except for bed rack, snow plow, and glow plugs are on a toggle switch. It works great for plowing!
    72 Postal Jeep - Yet another project

  3. #3
    Join Date
    Mar 2006
    Location
    Harrah, Oklahoma
    Posts
    89

    Default

    I would, and have talked to him but the truck sat apart for 7 years and that has caused him to feel less than responsible, and I am sure it is an electronic failure, not a physical failure. I'm still looking for a cure. The funny thing is that in the event of total electronic failure it is second gear that it defaults to, not skips. Thanks.
    95 GMC C2500, 449,000 miles, 4L80E w/ 4.11, 4 inch exhaust, gauges, OPS relay mod, Cold start & Fast Idle controls, 18-1, PMD cooler, coolant updates, cam gear drive, Chinese HX35W clone., Kennedy Max Effort chip

  4. #4
    Join Date
    Jan 2005
    Location
    Denville,New Jersey
    Posts
    424

    Default

    Maybe there are no codes but how about double check the wiring.That multipin connector on the trans and even the connectors on the puter might need a close look.
    94 Chev Blazer, 6.5TD, 3.42, 4WD,Gear drive,,Remote FSD behind drivers headlight,,Mobil 1 in difs and trans,Rotella 30W, Over a quarter of a million miles !! Member -1.94 club.

  5. #5
    AKMark is offline Building another 6.2L powered vehicle
    Join Date
    Dec 2006
    Location
    North Pole, Alaska
    Posts
    400

    Default

    Sitting for 7 years? That's not great for it either.

    Have you pulled the pan? Changed the filter? Gotten rid of the fluid that is probably not quite up to spec anymore?

    I would be tempted to pull the solenoids and ensure they aren't plugged.
    05 2500HD CC LB LLY, 4x4, 3.73s 235/85R16's, webasto cab heater, to keep it warm.
    03 Buick Rendezvous - When you average over 80 miles per day driving around, you need one of these.
    85 K-5, 6.2, SM465, Rockwell T221, 1 tons, 36's. More goodies to be installed as time and money allows.
    82 K20, 6.2, SM465, NP208, stock except for bed rack, snow plow, and glow plugs are on a toggle switch. It works great for plowing!
    72 Postal Jeep - Yet another project

  6. #6
    Join Date
    Mar 2006
    Location
    Harrah, Oklahoma
    Posts
    89

    Default

    Have pulled and checked, multiple times, the plugs on the transmission. Took it back to the mechanic that rebuilt it and went for a drive, did some testing and he says the shifts are delayed and hard, sounds like a TPS problem to him.

    Hooked up GMTDScan Tech and discovered that it shows no vehicle speed though my speedometer works just fine. Going to check out the VSS more closely when the rain quits, also will remove and clean the TPS.

    I'll let you know what I find.
    95 GMC C2500, 449,000 miles, 4L80E w/ 4.11, 4 inch exhaust, gauges, OPS relay mod, Cold start & Fast Idle controls, 18-1, PMD cooler, coolant updates, cam gear drive, Chinese HX35W clone., Kennedy Max Effort chip

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