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
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