zracer323

iTrader: (12)

To give you a little background, after installing a built 4L60E, I cannot get the thing to respond to any changes in the tune dealing with the 2-3 shift. I suspect it is a pressure issue at WOT because the cars shifts perfectly at partial throttle. It will bang the rev limiter on the track before shifting, but on the street it will shift around 6000 rpms every time no matter when the shift is being commanded.

I have attached my tune and log file from a run I made on the street tonight. Note I am commanded the 2-3 shift to happen at 5200 rpms and 58 mph. I logged Force Motor (PCS) Line Pressure on this run. Does anybody know what these values should be? Should they match the Max Pressure on the Auto Shift Properties tab in the tune?

Any help is greatly appreciated.

stick1975

I have a similar problem with my 4L60E in my 01 silverado. No matter where I set the upshift point, if I stay on the floor with it, it will hit the rev limiter too. Mine only does this on the 2/3 upshift. Was yours built with a Trans Go shift kit/shift reprogramer kit? Mine started to randomly flare up on the 2/3 shift with light throttle, but would shift firm most of the time. So I pulled it out and took it back to my builder. I think my builder said 3rd gear clutches were burnt, and he changed the 3rd gaer drum bc the trans go kit said remove a check ball that wouldn't seat at high rpm and to put in a metered orifice. He put a stock drum back in, and I've just been living with till we have time to try something else like try another valve body. Hope you figure out what the problem is.

72sstaylor

I had this same problem after my cam install and tune. My tuner raised the rev limiter up 150 rpm and its perfect now. Hope this helps

CoolAid

Try this stuff first:

https://ls1tech.com/forums/automatic...tm-w-pics.html