Hi I have a boosted 2011 Silverado with a 6l80 tranny in it I just put a 2600-2800 circle d converter in it and now when I get on it there is a spot around 4K where it feels like it skips then hits hard I only did it a few times because I am afraid to blow the tranny up. Has anyone had an issue like this before?

 

Different everything, but mine did it right before the 1-2 shift. It felt like it went into neutral then BANG shifted. I overfilled the trans about 1/4 inch above the full mark and this fixed my problem.

 

It's a clutch to clutch transmission, so the handoff from one clutch to the next needs to be calibrated. What is happening is the oncoming clutch applies too late relative to the offgoing clutches release. So you lose wheel torque and the engine free revs. Then when it finally applies, it slams hard because of the discrepancy between clutch speed and engine speed. Gotta get someone who knows how to calibrate that.

 

I reread his post and he didn't say anything about it shifting at that 4K spot. It doesn't seem like it would if he was getting on it, maybe he doesn't know?

 

If its not during a shift then there are bigger issues

 

was the converter spec'd by circle d or just off the shelf converter???
what tuning changes have been done?

 

It was sped threw circle d I call and explained what was done and told them my dyno numbers. I hope it was during a shift too but honestly I am not sure It acted really weird and I only did it a few times because I didn’t want to blow anything apart. It was tuned threw black bear but not since the stall

 

prob a good idea to start by cleaning up the tune. if they didnt change anything from the stock tune (why would they if you had stock converter before) theres a few tables that handicap brake stall speed, could be locking up at 4k rpm depending on what gear you're in, etc