Transmission Thermal Bypass Valve

[Gangly]

The TSB regarding the TBV or the T1's (and other models) was updated July 26, 2022:

#21-NA-199: Information on Installation of a New Thermal Bypass Valve (TBV) - (Jul 26, 2022)

 

Involved Region or Country	North America, Canada
Condition	Some customers may comment on one or more of the following conditions: MIL illuminated Harsh Shifts Slip Surge Shudder Harsh Garage Shifts Harsh Range Shifts Noise Whine Growl Shake Vibration Delayed Shifts
Correction	Note: Review of the Global Warranty Management (GWM) system. This will indicate if the TBV has been replaced. Correct the existing customer condition following published Service Information. Open In New TabZoom/Print   Note: The TBV should be replaced one time for any transmission repair including Customer Concern Not Duplicated (CCND). Once the TBV Part Number 86774933, stamped with “70” as shown above is installed, it does not need to be replaced again unless it is determined the TBV has failed. The Transmission Cooler Bypass Valve (TBV) should be replaced with a new (TBV) that has cooler operating temperature and should be replaced when any transmission repair is performed including Customer Concern Not Duplicated (CCND). Note: The “70” may be difficult to read as a dot print maybe stamped over the “70”. The new TBV only needs to be replaced once. The new valve has a 70 stamped into the bottom of the valve. The “70” stamp is visible on the valve when installed on the transmission. The revised TBV has a full open temperature of 158f (70c). The previous TBV had a full open temperature of 194f (90c).

[Phantom 4D]

Thanks for posting. Just had my truck in for service last week. I'll be calling them today to inquire about this. 

 

[newdude]

Just to be clear for the 2019-2021 new body guys and gals, the bulletin only covers 6 speeds, not 8 speeds or 10 speeds in case you are looking for under warranty replacement of the TBV.  

Edited August 3, 2022 by newdude

[Gangly]

3 hours ago, newdude said:

Just to be clear for the 2019-2021 new body guys and gals, the bulletin only covers 6 speeds, not 8 speeds or 10 speeds in case you are looking for under warranty replacement of the TBV.  

You are correct, I should have elaborated further to identify that for the T1 model trucks, the TSB applies only to the Hydra-Matic 6L80 and 6L90 transmissions.

Edited August 3, 2022 by Gangly

[newdude]

6 hours ago, Gangly said:

You are correct, I should have elaborated further to identify that for the T1 model trucks, the TSB applies only to the Hydra-Matic 6L80 and 6L90 transmissions.

 

 

All good.  I know the guts will fit K2 8 speeds.  

Edited August 4, 2022 by newdude

[GreatWhiteMexican]

My 2020 Trail Boss Custom has the 6 speed. Should I schedule service for this and have this done or is this more if I have a problem? I do have a travel trailer that I tow about 4-5 months a year.