4L60E Shifting Issue When Warm?
03-04-2017, 01:49 PM
#1
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Location: Jenkins, KY
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4L60E Shifting Issue When Warm? Guys, I'm having issues with a 4L60E transmission that seems to want to go into limp mode when it gets warmed up. I ran some searches, but don't find anything that really helps.
The vehicle is a 2004 Chevy Colorado pickup, that I swapped a 5.3 into a little while back. The trans is the 2004 model year that came in the Colorado, with the bell housing and front pump/input shaft changed to work on the V8. The trans was completely rebuilt at the time of the swap, new Beast sunshell, new Z-Pack clutches, new LS1 OEM torque converter (factory stall), and a Stage 2 reprogramming kit from Tru-Tech.
The engine and trans are being run with an E40 PCM, and T42 TCM, which is pretty standard with Colorado LS swaps.
The truck runs and shifts perfectly when cold, then after about 20 miles or so, will downshift to 3rd gear, and usually not go back into 4th until about 70 mph. Sometimes after a few miles it'll go ahead and shift into 4th again, but usually I have to pull over and cycle the key off/on. There are no CEL, no codes, either engine or transmission.
This thing has me pulling out what little hair I have left...is it a tuning problem, or a transmission problem? I hate to haul it to a shop and try to have it tuned if there's something wrong with the trans...
The vehicle is a 2004 Chevy Colorado pickup, that I swapped a 5.3 into a little while back. The trans is the 2004 model year that came in the Colorado, with the bell housing and front pump/input shaft changed to work on the V8. The trans was completely rebuilt at the time of the swap, new Beast sunshell, new Z-Pack clutches, new LS1 OEM torque converter (factory stall), and a Stage 2 reprogramming kit from Tru-Tech.
The engine and trans are being run with an E40 PCM, and T42 TCM, which is pretty standard with Colorado LS swaps.
The truck runs and shifts perfectly when cold, then after about 20 miles or so, will downshift to 3rd gear, and usually not go back into 4th until about 70 mph. Sometimes after a few miles it'll go ahead and shift into 4th again, but usually I have to pull over and cycle the key off/on. There are no CEL, no codes, either engine or transmission.
This thing has me pulling out what little hair I have left...is it a tuning problem, or a transmission problem? I hate to haul it to a shop and try to have it tuned if there's something wrong with the trans...
03-09-2017, 10:37 AM
#2
You sure that its not shifting to 4th? Or is the torque converter not locking up? Very different things. I believe if any misfire is detected at all then the torque converter will not lock up. And sometimes no code will be thrown either. I had this problem with my 5.3L in my 2000 trans am. Tuned it out by turning off the multiple misfire code in HPTuners.