GMC Sierra 8L90 Transmission - Oil Level Check - Thermal Bypass?

[Adam Henningsen]

Hi.  I have been researching the procedure for checking the transmission oil level on my 2018 GMC Sierra 1500 with 8L90 Transmission.  I found a service document that says if the transmission is equipped with a Thermal Bypass valve, than the proper procedure for fluid level check is to heat transmission to 194 F and then let it cool to the 98F -113F range to do the fluid level check using the check plug on at the oil pan.  Here is the document I am referring to: https://static.nhtsa.gov/odi/tsbs/2019/MC-10158827-9999.pdf.

 

Does anyone know if this applied to my vehicle?  What vehicles come with Thermal Bypass valve?

 

 

Thanks,

Adam 

[newdude]

1 hour ago, Adam Henningsen said:

Hi.  I have been researching the procedure for checking the transmission oil level on my 2018 GMC Sierra 1500 with 8L90 Transmission.  I found a service document that says if the transmission is equipped with a Thermal Bypass valve, than the proper procedure for fluid level check is to heat transmission to 194 F and then let it cool to the 98F -113F range to do the fluid level check using the check plug on at the oil pan.  Here is the document I am referring to: https://static.nhtsa.gov/odi/tsbs/2019/MC-10158827-9999.pdf.

 

Does anyone know if this applied to my vehicle?  What vehicles come with Thermal Bypass valve?

 

 

Thanks,

Adam 

 

 

All 8L90 in the trucks have a bypass that I know of, so the with TBV procedure would be the one you would want to use.