Topic: Question about trans flush

[dexetr30]

Is it possible to use both lines for the trans cooler to flush the trans? What I'm thinking is I can put the line that goes back to the trans into a gallon of new atf +4 and I can put the line that feeds the cooler into an empty container. My thought is that this will pump the old atf into the empty container and allow the other line to draw in the new atf. Running the engine while slowly shifting through the gears should allow all the old atf to drain. This way the trans pump does all the work.

I hope I relayed all the above correctly in comparison to what's in my head.



Does anyone know if this will work?

[Jeffy]

I wouldn't do it.  There's a slump pan in the transmission and the new oil will mix with the old so you'd need a lot of new oil to flush out all the old oil as well as flush the contaminated oil out.  You'll also want to check the screen for the oil pick-up which requires the pan be dropped.

[Bounty Hunter]

I've seen where that method is recommended AFTER you drop the pan and change the fluid and filter.  Then you can get rid of most of the bad stuff, and the pumping method will change what is in the torque converter and other places.

[dexetr30]

I wouldn't do it.  There's a slump pan in the transmission and the new oil will mix with the old so you'd need a lot of new oil to flush out all the old oil as well as flush the contaminated oil out.  You'll also want to check the screen for the oil pick-up which requires the pan be dropped.

Makes sense Jeff. By "screen" do you mean the filter? If so, I planned on replacing that at the same time anyway. I should have mentioned that in my initial post. So, if I drain the pan, replace the filter and then go through the steps I mentioned in my initial post, will what I mentioned work? If not, is there a preferred method of home flushing?

Here's the entire plan in order.
1. Jack up the Jeep and place jack stands under the rear axle tubes. One on each side.
2. Remove the drain plug in my trans pan and let the atf drain thoroughly.
3. Remove the pan and clean or replace the filter.
4. Re-install the filter and pan.
5. Add three quarts of atf to the pan.
6. Flush the system as described in my initial post until the fluid runs clear.

[oldjeep]

Sounds like a good plan to me, but you're going to need to run a few gallons through to really flush it out.

[dexetr30]

Sounds like a good plan to me, but you're going to need to run a few gallons through to really flush it out.

Yeah, and it ain't cheap. Local dealership wants $32.00 a gallon. I was thinking Wal-Mart brand. Problem with that is I'm not a big Wal-Mart fan and I'm not sure of the quality.

I wish the torque converter had a drain plug.

[Jeffy]

Well, you could flush it with cheap stuff at first then fill it with the good stuff after.

[dexetr30]

Well, you could flush it with cheap stuff at first then fill it with the good stuff after.

Thanks Jeff. Good idea.

[aw12345]

If I remember correctly the torqueflites use just plain dextron atf should not be all that expensive

[dexetr30]

If I remember correctly the torqueflites use just plain dextron atf should not be all that expensive

My manual says to use atf +4. Is it the same as mercon dexron? Last I knew Daimler Chrysler was not supporting the use of any other fluid. Am I wrong?

[aw12345]

Mercom should be allright, they made that for the later transmissions with overdrive, the difference is that it breaks down at a higher temperature than the older fluids, Dextron 4 is the latest greatest and that stuff is pricey, but it should not be necesary for a plain old 3 speed automatic

[oldjeep]

I wouldn't use anything but ATF+4 in a 30RH.   The Penzoil ATF+4 runs about $5 a quart