Seth 2500HD

Ok. 4l80e in 04 2500hd - 175k miles
"Slide bump"? From 1-2, (harsh shift)
Sometimes seems like it's trying to skip 2nd alltogether, and shift to 3rd - others its holding 1st way too long (like to 4k, mild throttle). Quite often it seems to be starting in 2nd, then will downshift to 1 after 10mph or so.
Now it seems to hang between 1 and 2.
1st time i changed fluid, it was jet black, lots of filings (glitter - no chunks). Dropped pan yesterday, about 1k miles, fluid is black again, more filings. Took valve body down and found marring on seperator where the checkballs sit.





Can this be the source of the problems? Also, is it safe to assume someone's been in here before- judging by the gasket....

GMCSIERRA5.3

Torque converter is your problem bud..time for a rebuild and a new torque converter

Seth 2500HD

Could you elaborate on why you think it's the torque converter? I only have a rudimentary understanding of their function.