I decided to take my truck 4 wheeling at the sand dunes of pismo beach this week. I had been having trouble with my 4 wheel drive, and of course after some rough driving, it failed to work. I figured out what it was, but I had to drive back in 2 wheel drive. I finally made it back, but not after about an hour of tire spinning, transmission overheating driving in the sand. My transmission temp only got above 210 for a little while, but I did notice some slipping and bad smells towards the end. Once I got on the pavement, I realized I have problems. When accelerating from a stop, I get a bad shudder in first gear, almost like wheel hop, but comming from the transmission. In second gear I feel a bad vibration as the transmission seems to slip for a while. All the other gears seem fine and I have not trouble at highway speeds. Just the two low gears. Any ideas on what could be wrong? How about a recomendation for a good transmission shop in the bay area/central california area? Depending on how bad I damaged the transmission, I might even consider upgrading the valve body and torque converter that I have been putting off. Any recomendations? Thanks in advance for any help!