Check on the internet and you will find complaints about the Allison 1000 that it doesn't oil some clutches, 3rd I think, unless it is in that gear, and that the oil passages send the oil at an angle to the clutches so they don't engage straight on. That pickup truck Allison is another example of an old-time name getting contaminated by the bean counters, just like Detroit Diesel and the pickup truck 6.2/6.5. From what I can figure out, the Aisin is about 100 pounds heavier than the Allison, which must translate to extra beef.