You'll need at least 14 quarts according to AMSOIL, if you have a transmission cooler.
- I ordered 14 from AMSOIL and delivery is normally the next day, but I order a couple extra in case I kick one over or I don't want to run short.
Note: I run a V6 10L60 with 11.5 quarts that uses less fluid than the 10L80.
If you do run short, Mercon ULV has a higher temp rating than Dexron ULV; however, AMSOIL's specifications exceeds both Mercon and Dexron.
If I recall, you are installing the NextGen Drivetrain Valve Body Upgrade kit.
When installing, remove the transmission thermostat for better cooling but now you can also do a full flush of all 14 quarts without having to bring the transmission up to a certain fluid temperature.
Besides I can never get the tranny temp much past 165 Fahrenheit with a cooler that is disconnected from the engine's radiator coolant heater.
When you drop the pan, why not install a drain plug?
I recommend a good plug with gaskets and it does not leak.
(Superior Transmission Parts)
When you drop the Valve Body, another 4 quarts will slowly drip out into a catch basin. The transmission pan holds 4 quarts, 4 more quarts are in the torque converter and 1 quart in the cooler and lines.
After everything is reassembled:
- Prime the pan with 5 quarts of fluid
- Disconnect the output line from your cooler into a large drain pan
(To find the output line, before changing fluid, run the car to find the cold return)
- Then start your car
- Shift it into neutral
- Start pumping the rest of the fluid into the refill hole using a GM adaptor tool and an electric pump
(CTA Tools 7431 ATF Filler Adapter - M6x1.0)
- On average the dirty fluid pumping out from the tranny, changes color to clean just as I run out of fluid pumping in
- GM recommends to have no fluid drip from their drain straw
- So this is where the drain plug facilitates draining some fluid, if required
- I've provided the calculation for expansion and the result is very little fluid approximately, 1/2 quart
Coefficient of thermal expansion for oils and transmission fluids is around 0.0007 per degree C (0.07%/C).
https://bobistheoilguy.com/forums/th...h-heat.316726/
Summer time temperature change might be ambient air temperature 68F (20C), at start up, to around 180F(82C) at operating temperature. Or, around 62C.
Therefore, during the summertime, the fluid could be expected to expand 0.0007 x 62C = 0.0434 (4.3%).
10.8 L expands 464 mL
Therefore fill to the fill tube over flows, then remove 400 ml from the cooler.