Two problems related to automatic transmission cooler have been reported for the 2005 Chevrolet Trailblazer. The most recently reported issues are listed below.
Normal driving, I noticed some liquid spots on the driveway. After inspecting, I found that the transmission oil cooling line is corroded through, leaking transmission fluid. My Chevrolet Trailblazer has less than 60000 miles and is 5 years old. One line is clean, the other is corroded beyond repair. Transmission oil cooling lines have to be replaced.
While driving on the highway, my truck rpm's began to rev, and I began to lose speed. My Trailblazer would not shift out of second gear now. I discovered a leak into the transmission cooling line and replaced it. I've also changed the fluid and filter. After taking my truck to a local autozone for a code scan, which brought back no codes, I took the truck to my local dealer for a diagnosis. They charged me $105. 00 to tell me that the truck wasn't "throwing codes" I already knew that! they told me that it was going to be approx. $800. 00 just to pull the transmission apart to find the problem and $400. 00 to put it back in. That doesn't include the cost of fixing it! after consulting with an ase certified mechanic, I changed the tcc (transmission clutch converter) solenoid to no avail. The problem still exists! gm will offer no assistance until I pay the dealer to disassemble the transmission, then "there is a possibility" that the fix will be covered. This vehicle has not done any towing and only has 56,600 miles on it! there is no reason for a transmission failure!.