I bought my trailblazer from my brother in-laws only a week and a half ago and drove it 380 mules back to where I live. I was driving to town and the Rpm's started getting higher. I pulled over checked the fuild and it was where it was where it should be. Cycled through the gears and reverse was gone. Turned around and went home but i had to bring the rims up before it would even move, check engine light came on as soon as I started moving. Got home and parked it. Got a ride to the parts store, changed the fluid and filter and there was no metal in the pan, fluid was dark but didn't smell burnt. No rattling around the transmission when run through the gears while sitting still. I figured it was screwed and I was going to have to rebuild it but I ran across a couple of forums that discussed the boost valve failure. I'm trying a Hail Mary and ordered a boost valve from Sonnax hoping for the best. I'm currently stuck waiting on UPS to get here was just curious if I even have a chance in hell with this or if I should start shopping for a rebuild kit.