A 1998 Chevy Tahoe with good fluid levels was driven for only a bit over 35000 miles before the transmission failed. Why would this happen?

Answer 1

A transmission can fail in a number of different ways, and they severity of the problem ranges from minor to major. Without looking at the unit, it is difficult to say exactly what is wrong and why the unit only worked for that short a time (so few miles). Some issues can be handled with a minimum of time and cost. But others require removal of the transmission and some disassembly to determine the cause of the failure. In situations like this where a range of possibilities explains the symptoms, a professional should be consulted. There is little you can use as leverage to offset a lack of knowledge and experience as regards troubleshooting transmissions (or other things). Calls to transmission shops are in order, but know that no one will tell you what is wrong without being able to look at the vehicle. They would be guessing, and they can only offer a range of possibilities - and associated costs. And that is a "best offer" from the professionals. None of them is psychic nor can they use X-ray vision to see into the transmission from where they are. This is not sarcasm, but an honestly stated way to summarize the limits of the mechanic, and you already knew that. Under the circumstances, it is best to take (tow) the Tahoe in. If things are bad, you can always yell at GM after the fact and file complaints with consumer organizations in a attempt to get some fair treatment. But in the mean time, this vehicle needs to be looked over by someone "up town" who can pinpoint a cause and offer an estimate of repair costs.