One problem related to front suspension leaf spring has been reported for the 2003 Toyota Tundra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Toyota Tundra based on all problems reported for the 2003 Tundra.
Purchased a 2003 Toyota Tundra July 2016. Frame was undercoated by Toyota and did not seem to be any issues at the time of purchase. After a few months of ownership, I have been conducting some of my own maintenance under the vehicle. While under, I noticed large areas had the crc treatment chipping and pealing off. I called my local Toyota dealer (priority Toyota chesapeake, va) the service manager said the corrosion protection has expired and there was nothing further they could do. While attempting to grease my propeller shaft, I was on my creaper trying to pull myself under the vehicle. I grabbed part of the frame, in front of the leaf spring perch. While grabbing this section of frame and pulling myself under the truck, the frame crumbled in to my hand. There were a lot of rust flakes, large and small, I collected as much of the rust and flakes as I could and stored them in a zip lock bag. The size of the deterioration was about 7" long and perforated about 9/16" near the bottom of the c channel. I am very concerned about the integrity of the frame on this vehicle particularly in regards to braking system, frame cross members and suspension components. I called Toyota customer service soon after to report what happened. I told them my VIN and other information. They said they would call back in 1 business day. I received a call from Toyota today 10/27/16 and a representative told me that Toyota is no longer supporting my vehicle for any campaigns. I asked the representative for further literature regarding the frame corrosion programs for Tundras, however, Toyota will not let me have this information. At this point Toyota will do nothing to help or provide assistance in repairing their poorly designed vehicle. Please do not buy Toyotas because in the future there will be failures and Toyota will not stand behind their products. Plain and simple.