I have a 2006 GMC pickup. About 7 years ago when it had 20k on the clock, I decided to start messing with it. 3k stall converter, shift kit, headers, intake, exhuast, tune, etc. Lasted about 40k before the output shaft grenaded and took out the entire trans, literally. I threw the whole thing in the dumpster. Went with a reman that was supposedly freshened up. That lasted 4 months before the clutches went out. Tore it open only to find an old, worn tranny that had the case painted.
I gutted it, cleaned out the case, replaced everything with upgraded parts wherever I could. Billet output shaft, Borg warner clutches, Koleen steels, Sonnax servos, pinless accumulators, GM 5 pinion planets, the whole 9 yards. Sent the converter back out to get cut and cleaned, new clutch disc. I rebuilt the tranny myself in my garage. Took a while. I would wake up in the middle of the night and go remove the pump to make sure I put the band in, etc.
Finally got it going. Solid as hell. got 10k on the clock and there it goes again. I thought I was off on some of the tolerances or something. My dad is giving me heck, my wife is pissed. I send it out to a highly reputable trans builder to have them do the teardown to identify what I did wrong. NOTHING! Got a call today. The $900 converter let go and sent metal through the case and ruined just about everything. My build was good.
So here we are, an accumulative of $7k into my tranny now for an F'in daily driver pickup. It's a quick truck for what it is, but I have a baby on the way and I suppose it's time to settle it down for a bit. I'm going to retune it get it a little closer to stock for now.
It wouldn't be fun if you never had to work on it though, right?