Transmission reached 300F reversing trailer up a mountain

[tiwillia]

15 hours ago, newdude said:

 

 

Who did the flush and did they use the correct fluid?

 

Was the filter changed?

The flush was done by the dealership. They used the new Mobil1 fluid that GM recommends after the TSB on the 8speed came out. The filter was not changed, they explained to me that it was a reverse flush that should clean the filter, so there wouldn't be a need to change it.

[tiwillia]

Thanks for all the info - the torque converter not locking in reverse makes a lot of sense, it definitely never felt like it locked even when getting up to 5+ mph.

I'll be scheduling another ~$300 transmission flush with the dealer today. Wish I didn't have to use the dealer.