jlarson69 Posted May 22, 2020 Report Share Posted May 22, 2020 I just bought a 2003 Silverado SS AWD with around 140k. I would like to firm up the shifts and extend the life of the transmission. What are some possible upgrades I can make while the truck is still in the vehicle? I have this list from an older thread made by Zippy. Are these still relevent? Any good guides how to do it? Superior Products kit part number 4L60E-L, Sonnax boost valve part number 77898E-K, Corvette servo, billet 4th gear Superior Products servo, aluminum 1-2 accumlator piston, and brand new GM spacer plate with the new bonded gasket/plate kit drilled to match the kit. I also plan on using Valvoline Maxlife full synthetic ATF. Quote Link to comment Share on other sites More sharing options...
someotherguy Posted May 22, 2020 Report Share Posted May 22, 2020 Can't speak to the other items though they sound good and if a respected SS tuner recommended them....... But I can say that at only 80K-ish miles my 4L65E had worn the separator plate out, so I'd say at 140K yours could probably benefit from replacement. Mine was also shifting stupid hard from 1-2 even at part throttle, so my transmission guy replaced the 1-2 accumulator spring with a different one, softened it up a little, though it's still a bit harsh - I think my PCM has a janky tune on it from the previous owner. It still gave me some odd behavior like a hang before shifting into 2nd (or 3rd? can't remember; it's been a while) and a momentary whining noise under acceleration, the trans eventually gave me warning signs of crapping out around 140K so I had my guy build it. 140K is a long time for a 4L65E to live in an SS, if you ask me; I'm surprised mine lasted that long. It still caught all the gears but had gotten loud and I was depending on it as a daily driver for just under 100 miles a day so I didn't want to wait for it to completely let go. Richard Quote Link to comment Share on other sites More sharing options...
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