Magnuson Supercharger, Valve Train and other supporting mods. 2007-2013, 5.3L Chevy Tahoe

[Chrismnj]

Ok, I need some help here, what else could cause hard downshift?

Bump

 

[67RS427]

Bump

Harsh downshift during part throttle or coming to a stop?

 

[Chrismnj]

Harsh downshift during part throttle or coming to a stop?

no throttle coming to a stop

 

[67RS427]

no throttle coming to a stop

What MPH is it downshifting to 1st gear?

 

[Chrismnj]

not sure, would say around 10

 

[67RS427]

not sure, would say around 10

That's pretty normal... My guess would be too much pressure or a TQ Management setting. I'd need to see the tune file. Contact Black Bear if they did the tune. 6L80 transmissions are a pain to tune and even harder on trucks.

 

[Chrismnj]

That's pretty normal... My guess would be too much pressure or a TQ Management setting. I'd need to see the tune file. Contact Black Bear if they did the tune. 6L80 transmissions are a pain to tune and even harder on trucks.

cleaned TB and sent them another log, hopefully they will be able to do something with it

Edit, will try changing fluid as well

 

[67RS427]

cleaned TB and sent them another log, hopefully they will be able to do something with it

Edit, will try changing fluid as well

Make sure your overfill the transmission by an extra QT. They like extra fluid...

 

[Chrismnj]

Make sure your overfill the transmission by an extra QT. They like extra fluid...

ok thank you, is there any advantages of porting and polishing TB on this truck?

 

[Chrismnj]

Member of another forum claimed that installing TB spacer resolved his issues with hard downshifting, believe it was on trailblazer SS.