My 2005 lly with a built trans has developed a slow 1-2 shift. The trans seems to shift fine everywhere else except 1-2 under heavy throttle. Normal driving it seems ok. The converter seems likes its locking correctly. And it never throws any codes or goes into a limp. The truck doesn't see too many miles its mostly just a toy/cruiser. The trans build is probably 5 years or so old but maybe has 15k on it. Too me it seems like a valve body issue. Last summer I pulled the valve body out and pulled it apart looking for burs in bores and the only visual thing I found was the F trim valve end sleeve had a small bur on it, so i smoothed it out and cleaned everything and reassembled it. Seemed like it got a touch better, but to my understanding the the F trim is for the converter and has nothing to do with 1-2 shift. Just looking for some opinions, would hate to pull the whole trans to have it gone thru if I'm on the right track with thinking its a valve body issue. Thanks for any input in advance.
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