Details:
In February of this year, after saving for over five years, I took my truck in to a reputable shop for an LS3 swap. Went with the 6L80 transmission as well to have a couple more gears available. Nine months later and I'm working through an extremely pesky issue that continues to befuddle the best technicians in the land. My truck is a triple-locked '94 with 245,000 miles on the body.
Situation:
About 40% of the time the shift from first to second gear causes a lurch or stutter. It's experienced as a firm shift, what then feels like a release, and then it grabs and goes. Calling it a stutter is not out of the question. I've performed a series of tests across every possible permutation and believe it to be torque related. Issue occurs more often when going uphill and/or turning at a gradual rate of acceleration. It happens less at flat grade and rarely when descending. Outside temperature, engine temperature, and type of terrain does not matter. Higher shift points are smooth as silk. My father-in-law has the exact same cruiser, took it to the same shop, performed the same service, and has no issues whatsoever.
Solution efforts thus far that have proven ineffective:
In February of this year, after saving for over five years, I took my truck in to a reputable shop for an LS3 swap. Went with the 6L80 transmission as well to have a couple more gears available. Nine months later and I'm working through an extremely pesky issue that continues to befuddle the best technicians in the land. My truck is a triple-locked '94 with 245,000 miles on the body.
Situation:
About 40% of the time the shift from first to second gear causes a lurch or stutter. It's experienced as a firm shift, what then feels like a release, and then it grabs and goes. Calling it a stutter is not out of the question. I've performed a series of tests across every possible permutation and believe it to be torque related. Issue occurs more often when going uphill and/or turning at a gradual rate of acceleration. It happens less at flat grade and rarely when descending. Outside temperature, engine temperature, and type of terrain does not matter. Higher shift points are smooth as silk. My father-in-law has the exact same cruiser, took it to the same shop, performed the same service, and has no issues whatsoever.
Solution efforts thus far that have proven ineffective:
- Front and rear axles serviced (tangential but good to be aware)
- Myriad of changes to engine and transmission programming following inspection of data.
- Examination of transmission wiring to confirm proper wiring.
- Replacement of the transmission controller.
- Transfer Case Rebuilt
- Full replacement of entire transmission which was ~4 months new at time of replacement.
- Rear U Joints replaced.