I was driving along at about 40 mph and heard a roaring sound coming from the transmission. I pulled on the should and put the engine in park to hear better. I put the car in reverse and it would not move. Luckily, I was able to keep driving forward until I got home. What could cause this and how can I correct it? I checked the ATF fluid levels and the fuse.
What year Trailblazer, how many miles, how often has it been serviced, what does the fluid look/smell like??
2003 Trailblazer with 250k miles. It ets fair service. The fluid looks light brown.
Any color other than red is a very bad sign.
I suggest that you have the vehicle towed to an independent trans shop for evaluation.
If you are very lucky, it is possible (but not probable) that a fluid and filter change will do the trick.
Much more likely is that this 250k mile trans is ready for transmission heaven.
Incidentally, did that “fair service” include a fluid and filter change every 30k miles?
If not, then the vehicle has had service that is way below the level of “fair”.