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Transmission return line clarification

97jeepxj1

NAXJA Forum User
Location
missouri
Just want to clarify that the rear most line on the aw4 in my 97 is in fact the return before I go about flushing out my transfluid.
 
would I be better off disonnecting the trans line and flushing it a gallon at a time or just draining the pan and refilling it, letting it run a few then repeat?
 
I do the second option, usually 3-4 times, running a few days between drain/refills, and do it while it's hot. You will drain right at 3 quarts each time. I drain with a funnel into an empty gallon oil bottle with the measuring window in the handle. Then, I just refill the same amount of clean fluid. I think it's a bit less of a "shock" to a high-mileage transmission than flushing.

I actually just went through this last month. Now that I have clean fluid, I've decided that I'm just going to do a single drain/refill each time I change the oil. It's good insurance, easy to do and not that expensive.
 
I disconnect the line, flush out a gallon, refill it, and repeat. Takes all of about 5 minutes if someone is starting/shutting off the engine for me.
 
My problem is that I have no idea what fluid is in it. The PO did a trans swap before I got it so no idea what he used and a shop swapped the torque converter on it a while back to fix the torque converter that the PO snapped a bolt off in and I don't know what they used either. I was just going to flush it out with 2 gallons of valvoline high mileage dex/merc
 
I disconnect the line, flush out a gallon, refill it, and repeat. Takes all of about 5 minutes if someone is starting/shutting off the engine for me.

That certainly isn't a bad way to go either...

When the OP said "flush" I was thinking about the way shops flush and clean with a machine. I don't see any drawbacks to letting the transmission pump it out and refilling like that, and is quicker than my method.
 
My problem is that I have no idea what fluid is in it. The PO did a trans swap before I got it so no idea what he used and a shop swapped the torque converter on it a while back to fix the torque converter that the PO snapped a bolt off in and I don't know what they used either. I was just going to flush it out with 2 gallons of valvoline high mileage dex/merc

In that case, I think I would do the flush rather than the way I do it. I think there would be less of a fluid mixing issue if you did the flush. You wouldn't be driving around for days with the possibility of two types of fluid mixed. I would probably do 3 gallons to try to ensure that you've replaced all of it.
 
should I just unhook the return line at the trans and feed it into my bucket? I have a clear 10 qt bucket from lowes with qt increments marked on the side.
 
That should work fine. If you have an aftermarket cooler mounted, you could disconnect it from the cooler output rather than at the trans. That might provide easier access than crawling under.
 
It worked and I only made a moderate mess. I did find that about 3-3.5 quarts it started pumping air so that was when I shut it down to refill
 
I've read somewhere that supposedly valvoline told someone they are compatible. I should make enough tomorrow to grab another gallon no problem. Thursday I'm ordering a set of 3.5" rubicon express coils so it sits a little better after the rear add a leafs I added in place of it lift blocks. The 2.5 inch re add a leafs rearched my springs a bit more then expected. Sure seems like more then 2.5. I was also going to order a cheap set of daystar 1" lift shackles with coil springs. Going to hopefully get by for a couple weeks then get some cheap rough country fixed lower control arms
 
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Compatible with what? Chrysler says ATF+4 is "compatible" with Dex/Merc (or a "substitute" basically), but Dex/Merc is the only fluid ever put into an XJ off the factory line. Since we don't really know what's in yours, I think you're doing the right thing by using Dex/Merc.
 
Just ment that dex and atf+4 supposedly are. I know it's supposed to have dex/merc but there's a bunch of people that say atf+4 is the way to go. I just know that even with the trans swap that was done over 2 years ago, and the torque converter the shop did, my trans fluid was still a little dark and burnt smelling so I wanted to change it out and go with the dex. I also noticed some goofy transmission shifting today driving on the highway to pick up some trans drop pucks a buddy from my local jeep club made me out of some round steel stock. That may actually have more to do with the hacked and cobbled back together wiring harness though then dirty trans fluid
 
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