Hey Everybody,

I give up and need some help on this one. I have now broken and replaced the NP 435 transmission in 78 F250 3 times. Took it out and welded the cast iron once, replaced the housing and now broke it again. No offroading, no racing, not even towing. In fact, the last transmission with a brand new housing (used obviously) lasted 3 weeks. I had a bad u joint that was causing vibration that I replaced but it doesn't seem like a vibration would break cast iron, three times. Anyway, the vibration is gone. The tranny and the transfer case are newly rebuilt and the engine is less than two years old. The truck is straight and I've done a lot of work on it. It's in great shape, other than the fact that it goes through transmissions like candy. Any questions, any advice???

Much appreciated.