Proper Transmission Fill Level

[Jkb242]

On my Denali, the transmission dip stick has two separate fluid measurement hashed areas. The lower one for cold (ambient temp) and a “hot” or normal engine operating temp ~100c. With the engine running and in park or neutral and below operating temp, is an indication within the lower hash marks acceptable as an accurate indicator of sufficient fluid? Would it be more accurate to check the fluid immediately after a drive with engine at temp presuming transmission would be at sufficient temp to use the upper “hot” area? I wasn’t actually aware of the upper marks since I would routinely check the level before driving it while in park with the engine running.

Thanks.

 

[mrrsm]

https://cdn.dealereprocess.org/cdn/servicemanuals/gmc/2006-envoy.pdf

 

[Jkb242]

Very helpful especially the cold check being the primary indicator. Although there is no specific description as to how one arrives at the “HOT” condition. Unfortunately, only the “cold” measurement method is clearly define with cautions about adding only if the “hot” measurement undefined.

But thanks for the information. Certainly appreciated other inputs that expand on the methodology to accurately establish a valid “hot” measurement check.

 

[mrrsm]

The "Hot Condition" method for Checking Transmission Fluids is usually induced by Idling the SUV for around 10 Minutes or so.. .and always ... Take the Measurements with the Wheels Chocked, the Engine Running, the Transmission Shifter in Park and the Emergency Brake SET.

 

[Know1else]

The cold check is accurate, yet the fluid expands with heat, if you are on the cold line, you should be good.

If it is a little low, you’ll notice hard shifts before its warm up…

You want to check the range at high temp to ensure you are not overfull, the climate and normal operating temperature of your vehicles transmission could vary, whats level works during winter, might be overfull for summer.

I have heard ol’ guys say you don’t need to change transmission fluid, the pan has no plug…but if you start experiencing transmission hiccups, new fluid is the place to start.

I lost my intercooler, in the radiator, and mixed coolant into the transmission…which interrupted normal operation at some point.

I’ve been through significant flushes and filter changes, more on this, than anything i’ve ever driven.

After fighting the exhaust crossmember to remove the pan a couple times, i bought a 12v oil pump with battery clamps from northern tool on sale.

I cut and looped the intercooler lines to Bypass the radiator and added an aux oil cooler to the mini oil cooler after the radiator intercooler.

I have since had a full breakdown, and replacing the TCM restored functionality. Can’t program it myself, so we tow strapped it legally, on the Right of Way, like Americans can decide they’re free to do…

Keeping the transmission cool will increase the longevity, but we’re fighting optimal engine operation at 190•F….when cooling the 6l80e.

They have a bypass valve for the newer 6l80 to run fluid through the cooler constantly, and adding the extra oil cooler can help.