2011 Tundra shifting in an out of OD

Hello My Name is Carla, I have a 2011 4 door Tundra 4x4 with 6" of lift running 37's on 20" rims, I have started having a problem with my truck shifting in and out of OD, I have had the transmission serviced with no issue's being found and was told maybe I needed to add an external transmission cooler to it, however the temperature gauge never gets to the middle.
Any suggestions on what could be making it do this.
Thanks Carla

 

Did you re-gear the differentials when you put on the 37’s? The final drive ratio is affected by much larger tires and power suffers which is why it will shift from 6 to 5 constantly. It is “sensing” a higher load and because your RPM’s are lower due to the lower final drive ratio it will need to shift to maintain power.

If you haven’t re-geared, you will want to look into 5.29 gears for both diffs.

 

Welcome from San Diego ca.
You need 5.29’s on the differentials. Or you need smaller tires.
Call for details. DirtyDeedsIndustries.com

760-877-4234

 

Welcome from NC!

 

Welcome from Nevada

 

Welcome from Maryland

Definitely need to change gears as mentioned

Until that is done I would try driving in “S” mode locked in 5th gear around town intill your on hi- way above 65 mph

 

This is also good advice. If you're in sequential mode and locked in 5th gear the torque converter will stay locked and keep transmission fluid temp lower overall.

With 37's and stock gears I probably wouldn't ever shift it higher than 4th... because.. power.

 

Thank you all for the comments, I was also told that I would need to have the computer reprogrammed once I re-geared the differential, because it would drastically reduce my fuel mileage, do any of you know if that is true and where would I have that done at?
Thanks
Carla