I'm new to this but it looks like everyone here gets good advice. I have a 97 f150 with recent transmission problems. The rear transmission extension housing cracked and so did the rear output housing on the transmission between the transmission and the transfer case. This all happened while driving on the freeway when the rear u joint blew out. I have since replaced the transmission, transmission extension to the transfer case, and the driveshaft. The truck runs good now except when I need to take off quick, the transmission seems to slip till the rpms come up to 2k, then is slams into gear and breaks the tires loose for a second, then slips again. In addition, when shifting from park to reverse or drive, even if the truck isn't moving, there is a clunk from the rear of the truck. The drive shaft and u joints were all provided by ford, hoping that there ok, but the transmission i got used from a scrap yard. could it be the tork convertor causing the slipping? and where is that clunk coming from?