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4L65E possible upgrades while transmission is still in the truck

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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.

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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.


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