BK68SS

iTrader: (1)

Hello, I just had a reputable shop install a crate LS1 and a rebuilt 4l60e from a reputable builder. The shop that did the swap says they can't get car to shift properly. My transmission guy used a Shaffer shifter tool to bypass thepcm and harness and we test drove and it shifted great with the tester. I relayed the info back to the shop and they think the transmission is still bad. I called a different transmission shop and they think the Shaffer test should rule out transmission issues. I am currently stuck and my shop wants me to swap the trans. Does anyone else agree that a Shaffer shifter rules out the transmission as being the issue and point more to wiring, PCM or tune? Any information would be greatly appreciated. Thanks

bbond105

What is the transmission doing to make you say that it isn't shifting properly? More info.

BK68SS

iTrader: (1)

Thanks for the reply...Feels like it's in 4th gear by the time I hit 15 mph. If I take off faster, it seems to rev the engine between 2nd and 3rd I believe. the shop tried adjusting line pressures and couldn't change the way it shifts. My transmission guy takes off the plug to the trans and connects his Shaffer shifter and he shifts in and out of gear with no issues. He said he even controlled the line pressures. He thinks it's the pcm and/or wiring at this point. My shop doesn't trust the tool and believe it is still the transmission

bbond105

It sounds like a wiring or control problem. It could be a bad engine sensor, (MAF or TPS).

performabuilt

iTrader: (25)

If the trans shifts properly with the shaffer shifter I would say its not a trans problem as mentioned early shifts can be cause by TPS and MAF issues.

BK68SS

iTrader: (1)

Thanks, I will try testing these before attempting to replace the transmission