Tranny pan drop?

[demarpaint]

Not working has gotten the best of me, too much time to think. How far off would the would ALL-DATA or a shop manual be for the amount of transmission fluid needed for a pan drop and filter change? Eg: All data says transmission service 4 qts? Complete refill 9 qts? That would be if the TC was drained too. In this case I'm referring to just the pan drop filter change.

TIA

 

[Stu_Rock]

The amount you need could range from 1 qt less than stated up to the "complete refill" number. I usually buy 1 qt extra from the "service" number.

One time I had to let my van sit for a few days with the pan off. That continuous, slow drip that keeps going? It can nearly drain the entire unit. I had to pick up several more quarts of ATF to finish that job.

 

[HTSS_TR]

Originally Posted By: Stu_Rock
The amount you need could range from 1 qt less than stated up to the "complete refill" number. I usually buy 1 qt extra from the "service" number.

One time I had to let my van sit for a few days with the pan off. That continuous, slow drip that keeps going? It can nearly drain the entire unit. I had to pick up several more quarts of ATF to finish that job.

+1
If possible leave than the pan off for a day or two and buy 1 or 2 quarts more than the service capacity.

 

[demarpaint]

Wow, I thought it would be maybe a qt more to fill it. That drip could drain the TC? Typically when I did them I would pull the pan and filter, clean the pan, install the filter, and then the gasket and pan. Usually about 30 minutes or so dripping by the time I had the pan ready to put back on. I didn't realize it could exceed that number by more than a qt or a qt and a few ounces than the stated amount.

I was thinking of doing my Aerostar during my down time, its due for a pan drop and filter.

Lets say the unit held 9 qts and 6 came out vs the 4 that the book states. If I were to pull a transmission line for a flush after the filter installation, how much fluid would you suggest to extract to really complete a fluid exchange?

Thanks!

 

[UNC017]

Originally Posted By: demarpaint
Wow, I thought it would be maybe a qt more to fill it. That drip could drain the TC?


When I change the ATF in my cars that don't have torque convertor drain plugs (IOW, any of them newer than 1978...) I try to leave the pan off overnight. Sometime during the night, air starts working into the TC and by morning there are often another 2+ quarts in the pan, which probably means the convertor drained down to about 1/2 level (the level of the input shaft).

On the cars that do have drain plugs on the TC- opening that plug drains much *more* fluid by itself than what you get out of the transmission by dropping the pan. Granted, those are old V8 cars with big TCs compared to a modern 4-cylinder or v6, but think about it- the TC is a 10 to 12 inch diameter by 4+ inch thick donut mostly filled with fluid. That's where MOST of the fluid in the transmission is located when its running and immediately after shut-down.

 

[demarpaint]

I'm learning everyday. I didn't realize that much fluid could come out leaving the pan draining overnight.

 

[tinmanSC]

Originally Posted By: demarpaint
I'm learning everyday. I didn't realize that much fluid could come out leaving the pan draining overnight.

Just a quick note... when leaving the pan off, it's probably best to not actually leave it off. Take the filter off, then bolt the pan back up by a few bolts to keep it in place. The reason for this? Leaves. I made the mistake of leaving the pan completely off and when I opened the garage door a gust of wind sent leaves flying into the transmission valve body, followed by a hour of delicate leaf extraction. Learn from my fail.

 

[demarpaint]

Good point. I was watching my buddy the other day do a pan drop on a Jeep, and there was a bit of a mess on the shop floor. He tossed speedy dry down and the dust of the speedy dry was blowing it up toward the open transmission. The shop door was open and the wind ended up blowing it away from the transmission pan.

I don't even like changing oil when its windy, the last drops end up being a PITA if I don't put cardboard under the work area.