Has anyone had problem with the tailpiece on the 4L60E transmission cracking? Had tx replaced @ 143K mis & within 10k miles started leaking tx fluid (1 qt every 150 miles on highway). Took back to shop, they contacted remanufacturer (Certified Transmissions of Oklahoma) & claimed problem was from vibration & that GM had a TechBulletin out on problem. Of course, claimed not under 3 year, 100k warranty.... another $950 later, had another tranny put in, along with new tranny mount (Sub'n already had a new Goodwrench 5.7 engine, new mounts, complete front end rebuild) & new driveshaft u-joints. Less than 1500 miles, rear tailpiece has cracked in same spot (on top) again. WTF? The original tranny lasted 140k without cracking the housing & here within a few thousand miles have gone through 2. Have not been running off road, towing or even exceeding 70mph on interstate (and have NOT let the wife drive the vehicle- her photo is in Wikipedia under road rage (hope she doesn't hack this site!). Don't see how this could be an alignment problem, all joints are tight & when up on rack, the driveshaft looks well balanced @ 50+ mph. Could it be Certified Transmissions supplied the wrong 4L60E transmission (twice?). Transmission shop is awaiting the distributor in Maryland to come to shop to see what is going on since this appears to be a problem with the remanufacture. Noted somewhere that there needs to be care on installing the rear seal as it can not be hammered into the housing. Anyone have any ideas? It's a 97 GMC K1500 w/5.7 engine