TCC lock / unlock at cruise. RPM hunt. 3.69 gears w/ 3500 stall

[japslpr]

Having an issue with the torque converter locking and unlocking causing an rpm surge at cruise. This normally occurs around 55mph up, in 3rd & 4th gears. RPM surge is around 50-100rpm

Not sure where to start at to adjusting for high stall converters.

Any ideas?

[oakleafresin]

Try raising your min tcc duty cycle table by 10% and see where that gets you. If the pcm detects misfires, it will unlock the tcc too.

[flame]

I've got a 100% stock 99 GT that had that problem for years. Long story short the trans lost 4th gear so being high miles I got a used trans. Same friggin problem so I thought WTF! Did a TAP reset and it took a few days to learn the shift pressure data again but the TCC works mint. Been a few months and everything is still working good. Worth a try on yours.

[rossko85]

Having an issue with the torque converter locking and unlocking causing an rpm surge at cruise. This normally occurs around 55mph up, in 3rd & 4th gears. RPM surge is around 50-100rpm

Not sure where to start at to adjusting for high stall converters.

Any ideas?

Yeah...take a look at your TCC apply/release tables...you need to max out the value in 3rd gear, or set it up higher in the table so you dont lock the converter in 3rd around town and get that slug surging effect! I would recommend getting into you WOT tables too for TCC and maxing out those values so you never lock your converter at WOT an any gear....

Remember when you set the tables to max, or 318 I believe for those tables in Apply, you also need to set the corresponding gear table to a smaller value like 317 in the Release area....hope this helps! It did for me! Nice smooth 3rd gear! no lock up or surging! Im running around trying to figure out now why I still get lock up in tap shift 3rd though....car only listens to what i say for tranny when im in Auto mode???