Volcom, can you post your mileage and a little more info on your van. If you lost power, you could have popped off a turbo boot. (There are two rubber 3" dia. x3-4" long hoses connecting the turbo compressor outlet to the top of each manifold.) They get oily inside and can pop off during a hard push. If that's what it is, clean them off by soaking in soapy water overnight. Then dry them off and re-install. You want the hose clamps fairly tight, but DO NOT overtighten as you can crush the manifold intake tubes. I know it is 7.3, 4R100 transmission, but it is really hard to help you out without actually hearing it, or knowing what's been done (or not). I would recommend at least pulling over, removing the dog house cover, checking all fluids, and also checking all bolts, clamps (on turbo, down pipe, manifold boots, air intake hoses, air filters, etc. You have to remember that all the additional vibration from the diesel means that everything should be checked and re-torqued if necessary. I found 3 of the huge main bolts not even finger tight on a friend's transmission! Also make sure you always let that diesel idle for 10 minutes after those long hard runs (as opposed to pulling over to eat and shutting it off quickly). It allows the turbo to cool down properly. Hope that helps. Post back updates or new findings and I'll try to help you out. -Jason