Transmission Fluid Change

[Tree Man]

What should the temperature be when draining the transmission fluid, cold or hot? I read on one of the post that a valve is closed in the transmission system. Will it be opened if the fluid is hot? I want to make sure the old fluid is fully drained. I have watch the You Tube videos on the transmission fluid changing and the process that goes into it.
Second the fluid that is used Mopar 8 vs ZF 8, or other, what is the best?

 

[cs in Alabama]

You can't make sure the old fluid is fully drained. You can only get 6 to 7 quarts unless you flush it. If you drain and replace the pan use the ZF lifeguard 8. Be careful where you buy it. Even if you buy it on ebay make sure the seller is an authorized stocking dealer of the fluid. Maybe I am psycho but the system is full of counterfeit parts and fluids. Get the real stuff.

On the other hand, you can flush it and get all the fluid. In that case, I would use the Valvoline Max Life. My dealer uses the Valvoline and does a flush for 275 dollars, which is cheaper than the pan and 7 quarts of ZF-8.

I assume you have seen this video:

 

[Big_E]

What should the temperature be when draining the transmission fluid, cold or hot? I read on one of the post that a valve is closed in the transmission system. Will it be opened if the fluid is hot? I want to make sure the old fluid is fully drained. I have watch the You Tube videos on the transmission fluid changing and the process that goes into it.
Second the fluid that is used Mopar 8 vs ZF 8, or other, what is the best?

I have been thinking about how to go about draing all the old transmission fluid and not just what's in the actual transmission, but also the transmission cooler and feed/return lines. The thermostatic valve going from the transmission to the cooler supposed to open somewhere in the 80-90F, if my memory serves me right. However, with the engine off and no oil circulation flow, I think the thermostatic valve will close on the transmission cooler lines. So my solution was this....Drain fluid from transmission while still relatively warm but not hot to the touch, than take off the pan to drain the remaining fluid left in the pan. After that, I disconnect both cooler lines at the thermostatic valve fittings allowing the old fluid to drain from the cooler and lines. That is how I get the most possible fluid draing out of the entire system. With that in mind, when you follow the specific refill procedure and top it off after shifting through the gears before the temperature reaches 125F, drive it around for a 10-20 min in town and park the vehicle. Let it cool off again down to about 85F. Start the truck back up again, wait for transmission temperature to reach about 100F and check the fluid level again while truck is running. Top off the transmission again since some oil now went into the cooler and lines. Just make sure you are done topping off the fluid before it reached 125F again.

 

[John Jensen]

Here are my notes on acceptable alternatives to the expensive Mopar

Valvoline MaxLife Full Synthetic Multi-Vehicle ATF (Vern Diesel – high miler, towing)
ZF Lifeguard 8 (Forum says same as OEM)
Ravenol (Forum says same as ZF Lifeguard but cheaper)
LiquidMoly ZF fluid (Forum good testimony)
Hot Shot Secret Blue Diamond D6 Severe (Forum good testimony)