Have some questions here about a 2018 Yukon with the 10L80...
I've seen two different procedures - my ALLDATA sheet for the 2018 Yukon (Current subscription) tells me to get the trans to 200deg and measure at or above that temp. However, I'm seeing plenty of posts on camaro6 and other newer vehicles (2022 silverados, for example, and even the 2019 Escalade in this thread) that use the same transmission state to check the temp once it's over 158, and should stay in the 167-176 range.
A few questions:
Was the temp window never changed for the 2018 (early) transmissions for fluid check, or did alldata never update the data for the 2018? Which temperature should I be checking at? (And if it's different than what my alldata sub says, why is that?)
The instructions recommend brake torquing to get to temp, which I followed (under 1500rpm, 10 sec on / 10 sec off). I've read that's really stupid (generates too much heat in the converter) - but is it dangerous if directions are followed and temps are watched?
Edit here: ACDelcoTDS lists the same temps as ALLData for the 2018 Yukon:
Warning: The transmission fluid temperature (TFT) must be between 95-100°C (203-212°F). If the TFT is lower than this temperature range, either idle or brake torque the vehicle to raise the fluid temperature. If the TFT is higher than this range, shut off the vehicle to allow the fluid to cool as required. Setting the fluid level with a TFT outside this range will result in either an over-fill or under-fill condition. If TFT is greater than 100°C = under-filled. If TFT is less than 95°C = over-filled. An under-filled transmission will cause premature component wear or damage. An over-filled transmission will cause fluid to overflow from the vent tube, possibly causing a fire that may result in serious bodily injury or severe vehicle damage, fluid foaming, or pump cavitation.
I've seen two different procedures - my ALLDATA sheet for the 2018 Yukon (Current subscription) tells me to get the trans to 200deg and measure at or above that temp. However, I'm seeing plenty of posts on camaro6 and other newer vehicles (2022 silverados, for example, and even the 2019 Escalade in this thread) that use the same transmission state to check the temp once it's over 158, and should stay in the 167-176 range.
A few questions:
Was the temp window never changed for the 2018 (early) transmissions for fluid check, or did alldata never update the data for the 2018? Which temperature should I be checking at? (And if it's different than what my alldata sub says, why is that?)
The instructions recommend brake torquing to get to temp, which I followed (under 1500rpm, 10 sec on / 10 sec off). I've read that's really stupid (generates too much heat in the converter) - but is it dangerous if directions are followed and temps are watched?
Edit here: ACDelcoTDS lists the same temps as ALLData for the 2018 Yukon:
Warning: The transmission fluid temperature (TFT) must be between 95-100°C (203-212°F). If the TFT is lower than this temperature range, either idle or brake torque the vehicle to raise the fluid temperature. If the TFT is higher than this range, shut off the vehicle to allow the fluid to cool as required. Setting the fluid level with a TFT outside this range will result in either an over-fill or under-fill condition. If TFT is greater than 100°C = under-filled. If TFT is less than 95°C = over-filled. An under-filled transmission will cause premature component wear or damage. An over-filled transmission will cause fluid to overflow from the vent tube, possibly causing a fire that may result in serious bodily injury or severe vehicle damage, fluid foaming, or pump cavitation.
- Note: This vehicle is equipped with an internal thermal bypass valve, located inside the valve body, the transmission fluid level should be checked only after the TFT has reached or exceeded an operating temperature of 100°C (212°F). Once the TFT has reached or exceeded 100°C (212°F), then continue to run the engine and allow the TFT to maintain a temperature between 95-100°C (203-212°F) before checking the fluid level as required.
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