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So im finally driving my 97 chevy, 6.0/4l80e and it has a weird shifting issue from what I think is 1st to 2nd or 2nd to 3rd, not exactly sure since i only drove it for about 10 minutes and only got to about 50mph before decided to stop messing around to prevent damage. Seems like it hesitates between gears and if i let off the pedal it will shift ok but if I continue to gas it it will then hesitate and then slam into gear. I then got home and checked the fluid and it looks like I overfilled it. Would overfilling it that much cause erratic shifting? I plan to drain it to make it right but curious if that amount would cause it to act like that. The level is about where the tip of my thumb nail is. If there's anything else I should check let me know.
Overfilling it is not likely at all to cause your issue.
In fact...based on your photo, I'd bet you aren't even actually over-full
Did you drop the pan and verify/mark the proper dipstick level?
The correct fill level is 1/8-1/4" above the pan gasket sealing surface on the case.
That dipstick looks factory and I'd be more surprised if it was correct than if it was off
Anyway, we need some more details on the swap. What has been done to the transmission. You say "finally" does that imply the truck is a project or the transmission was a project? Is the truck stock? I assume not since 97 would not be a 6.0.
And what is controlling it? Is it a stock ECU or an aftermarket efi system (holley, haltech, etc) or is it a standalone shift controller like a US Shift quick 4 or similar?
Just need some details before we can really point you the right way.
Regardless of what the right way is...I'd get a pressure gauge on it and get some numbers. That's going to be part of the diagnostic tree no matter what.
Overfilling it is not likely at all to cause your issue.
In fact...based on your photo, I'd bet you aren't even actually over-full
Did you drop the pan and verify/mark the proper dipstick level?
The correct fill level is 1/8-1/4" above the pan gasket sealing surface on the case.
That dipstick looks factory and I'd be more surprised if it was correct than if it was off
Anyway, we need some more details on the swap. What has been done to the transmission. You say "finally" does that imply the truck is a project or the transmission was a project? Is the truck stock? I assume not since 97 would not be a 6.0.
And what is controlling it? Is it a stock ECU or an aftermarket efi system (holley, haltech, etc) or is it a standalone shift controller like a US Shift quick 4 or similar?
Just need some details before we can really point you the right way.
Regardless of what the right way is...I'd get a pressure gauge on it and get some numbers. That's going to be part of the diagnostic tree no matter what.
The transmission is a stock 97 4l80e. Im using a 0411 pcm that was tuned by lsx performance. And yes when i installed it i verified that the dipstick is accurate so it is slightly overfilled. Im just wondering if overfilling it would cause this type of situation.
Weird shifting 4l80e 
