so a new rebuilt trans
You DO fill the converter with 1 quart of fluid. Note the depth of the converter, see how far back it sits inside the bellhousing.
Remove the converter, turn it over, fill the hub with 1 quart of mercon V
(You will be using 12-14 quarts of mercon V ONLY do not use anything else!)
Stab converter back onto transmission, 3 clicks, until it is as far back as it was before you removed it
Now install transmission, plenty of threads on this.
Good idea to clean out your trans cooler and lines with compressed air
I also have been known to use a product called Kooler Kleen from lubeguard, this will clean the trans coolers and lines so your fresh new transmission does not get contaminated with old fluid or bits of carbon, metal, etc
Drop pan, replace filter, replace pan
Add 4 quarts of fluid through dipstick
start truck, run it through the gears, with foot on brake run it from P to 1 and back a few times....add 4 more quarts of fluid with truck running, keep putting shifter through the gears
You are now 9 quarts in
The system holds about 11-13 quarts so now you add a quart at a time and take dipstick readings. The truck should start to engage gears, it will grab in R and D..... with the truck running and warmed up you can adjust the fluid level. until it reads correctly on dipstick
Take 1-2 quarts of mercon V and a funnel with you on first test drive.
Continue to check fluid level until happy with results.
Drive for 500 miles, drop pan, replace filter and 4-5 quarts of fluid
Drive for another 1000 miles, drop pan, replace filter and another 4-5 quarts of fluid
Now you are good for 60-90K miles before you should replace the filter and some fluid again