With no dipstick, I am assuming you are referring to a 722.6 transmission. You will need to buy a dipstick if yo want to change it. You cannot just blindly put a certain amount of fluid in. With a sump and torque converter drain it should take in the neighborhood of 8 quarts. Change the filter too. And the fluid has to be at a certain temp to get an accurate reading of the fluid level.

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Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record