Strong noises coming from transmission when slowing down

rek2007

I have a 2007 Trailblazer with 120k KM. I have it always in "auto" and today when I slowed down to make a hard left I felt a strong noise below the truck at the back and another at the front, like if the truck rolls over 2 stones and looses power and stability.

It looks like when the truck changes gears in "auto" when you reach a hard curve, it is not able to properly synchronize and loud noises come from below the truck. Like if gears or cogs are not assembled or not synchronized.

I changed to 2h and the truck goes fine. It only happens in "auto". I did not try 4H because I think something similar may happen and I don't want to make more damage to the car.

Any idea what is happening?

Thnaks a lot for your comments.
Rek.

Mr_Shiftright

Sounds like the transmission TCM thinks there is wheel slippage when there actually isn't, putting the car into AWD on dry pavement, which will cause binding in the differentials. I would definitely stay in 2H until you can figure this out. Maybe a scan of the TCM will reveal something, like a bad sensor.