I had snagged an old 1993 1500, 5.7 with the 4L60E. I believe about 370,000km of hard use. Fluid was dark, very dark but did not smell burnt. It had a 3-4 shift flare, a shutter when in lockup under light load under 2000rpm and it slipped bad when trying to pass on the highway and not in lockup. In fact, you couldnt accelerate to pass unless it was locked. Likely the original fluid.
I did nothing more than a fluid exchange via the cooler lines. I used some cheap Dex/Merc in it and not even a filter . After a few miles it almost ran like a top. The only issue is the shift flare remained.
I did nothing more than a fluid exchange via the cooler lines. I used some cheap Dex/Merc in it and not even a filter . After a few miles it almost ran like a top. The only issue is the shift flare remained.