Waaaaaay too much effort and risk IMO
. What if you bounced one of those 50 lb
magnets off while driving? What if you ran the motor too long with the pan open and it ran dry? I'd either pay someone to flush the transmission or
1) Drain pan (6-8 qts)
2) Top off with new ATF
3) Drive for 20 min
4) Drain pan (6-8 qts)
5) Replace external filter
6) Top off with new ATF
Safe, simple, and fast.
Just my $.02
This is not more simple or faster.
1. You are are doing 2 fluid changes instead of 1 and re-changing new fluid.
Lets say you got an entire 8 quarts out on the first change and lets also say that you got the trans temp past 170* so that oil in the cooler is circulating through out the system because there is a thermostat.
That is 47% new and 53% old fluid.
The second fluid change you get another 8 quarts. You are now removing some of the new fluid and and have replaced 23% of the total fluid.
A total of 70% in this almost perfect situation for only dropping the pan.
In my situation I removed 13 quarts out on the first and only fluid change, that is 76%. In your situation you are
using 16 quarts worth of fluid and getting 70%.
2. Taking the time to drive 20 min.
3. Spending the fuel to drive 20 min.
If the magnet bounced off the pan then my trans would be off its mounts for that heavy of a hit.
For there to be damage by turning on the truck the trans would need to be completely dry of oil for something to happen while running the trans with the pan off for 15 seconds.