Transmission Drain Question - Toyota Nation Forum : Toyota Car and Truck Forums

fj40supraman · 02-05-2005, 07:56 AM

Just bought 6 quarts of Amsoil Full Synthetic ATF and I want to get out as much of the old tranny fluid as possible (or it will continue to break down). Since I changed the filter about 20K miles ago I was just gonna drain and refill. I plan on draining the pan then disconnecting the return on the radiator (cooler) to let the system "pump" itself out. What I want to know is if it will hurt it to run it out of oil, as long as the car doesn't move? I hate to screw it up over a fluid change. Then I will also change the transfer case. Is it like running your car out of gas, or more like running your engine out of oil? Thanks for the help.

Toysrme · 02-05-2005, 09:16 AM

Quote:

What I want to know is if it will hurt it to run it out of oil, as long as the car doesn't move?

YES!!!

ekim55121 · 02-05-2005, 08:42 PM

how is it harmful to run it with out ATF fluid i dont wanna pull my whole tranny to get my old smelly ATF fluid out of there

anuthaCamry · 02-05-2005, 08:52 PM

there is no advantage to pulling the cooler hose as opposed to doing it the right way. both will take about 10 quarts to replace 90% of the oil, even if your transmission pump runs outa oil, there will still be oil in the TC, even more when it's spinning.

I've dropped and worked on trannies before, you just can't drain it on the car. pulling the hose is just confusing way to try to flush it ...

If you run outa oil (in the pan, there will still be lots in the TC) you're looking at some metal to metal grinding in that pump which is probably all metal, and designed to never run dry.

fj40supraman · 02-06-2005, 01:38 PM

So what is the best way to get as much fluid out? I know some places pump it out, I'm guessing thru the dipstick. I guess the real question is how do you empty the transfer case minus dropping it?

anuthaCamry · 02-06-2005, 01:49 PM

you can only drain about 45% at any one time, just keep repeating every day or so for about 4-5 times to replace 90-95% of the fluid respectively. You also get a chance to let all the old oil cycle out of all the different oil passages that would just stay in there if the transmission were kept in park. I've done two drains so far and I think that I will grab the filter and diff box on the third try. And just do a simple drain for the 4th.

Don't forget to buy drain plug gaskets.

bonox · 02-06-2005, 10:29 PM

One assumes that all of this stuff only applies for slushboxes. Manuals are still simple drain and fill once types. ?

anuthaCamry · 02-06-2005, 10:42 PM

fuckin' eh

(yes indeed, manual transmission gearboxes lack the constant volume requirements inherent to all automatic transmissions)

anuthaCamry · 02-06-2005, 10:43 PM

gear oil smells worse though...