I think this is the biggest issue with BTS, and well I am prolly making an educated accusation coming from the buisiness as someone who has rebuilt several transmissions is that his demand has overcome his ability to supply.. This is just an opinion but when you have to build a 1000+ 4Rs/E4s right you run into how much will I have in a trans to make it right.. You tear it down, discover it has a junk planetary (planetarys are super duper expensive) and the customer demands the best for 5500 bones IIRC, but the billet shafts, clutches, converter, trick shift parts and machining and assembly time allow you to make profit when you have say 5000 invested.. So they buy cores, they use core transmissions as donors, EVERY MANAFACTURER DOES THIS INCLUDING CAT, CUMMINS, AND ALLISON, DETROIT BLAH BLAH BLAH.. So what do you do, call the customer and inform them, hey we are going to use genuine new BW parts to repair the transmisson right but your bill is now 7500 bucks... No they rob parts from other cores and peice it together, alot of people that build transmissions do this, I've done this for customers as well, it works, but is every single part isn't 100% some times, it's the risk you take. Clutches fail for a number of reason, planetarys get enough slop in them to cause binding issues during an unlocking event, low line pressure, warped cases, a shift valve that stuck after the break in period, it's hard to build a perfect transmission when you're adding 3500 bucks worth of Billet shafts and have say 1500 left for rebuilt parts and converter.. And now you take 500 for profit.. It's hard to sell it at what they really sell it for to make money and stay in buisiness.