When it shifts up or down shifts into 2nd gear the trans will slip when the the R's get over 4k at full throttle. I have 57K on my truck, at 13k the trans was rebuilt and the valve body replace while they over looked a cracked 1-2 accumulator. After two weeks in the dealer they changed the 1-2 accumulator. It ran great untill 55k miles and it started doing the same thing sliping in second gear. So I bought a 1-2 and a forward accumulator, corvette servo and a hard plate put them in. It shifts better but it jumps or skips rather than slip. please help thanks