ATF fluid change.
I have read a wide variety of thoughts on this, but I’ll pose the question custom to my current scenario. Have a 99 with an AW5(?) that has I’m guessing 100k on current fluid and filter. Fluid is pretty dark brown but not smelly and shifts great. I’m thinking about cycling thru a few drains/refills over the next 500 miles (not flushing). At this point should I also drop pan and change out filter? And if so...do this first and cycle a few refills of atf thru of do change if last. Or don’t bother and just refresh the fluid?? Thanks!
CF Veteran




Joined: Nov 2010
Posts: 5,839
Likes: 116
From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
Don't bother with the filter; on the AW4 (not AW5) it's a screen.
Do the drain/fill/drive until fluid stays red. May take 2-3 times.
Use Dex/Merc compatible fluid ONLY, no matter what somebody at the parts counter might try to sell you! Do not use ATF+4. While some AW4 transmissions work okay with it, many do not. Dex/Merc is the spec by Asin Warner, the mfg of the transmission and IMHO, it's the only correct fluid for the AW4.
Do the drain/fill/drive until fluid stays red. May take 2-3 times.
Use Dex/Merc compatible fluid ONLY, no matter what somebody at the parts counter might try to sell you! Do not use ATF+4. While some AW4 transmissions work okay with it, many do not. Dex/Merc is the spec by Asin Warner, the mfg of the transmission and IMHO, it's the only correct fluid for the AW4.
Last edited by tjwalker; Mar 2, 2019 at 06:10 PM.
Senior Member

Joined: Jul 2012
Posts: 793
Likes: 104
From: Aldie, VA
Year: 1999
Model: Cherokee
Engine: 4.0
I second the not bothering with the filter. It is literally a very coarse metal screen. It's not worth the hassle at all. If you wanted to keep it as easy as possible, get something to suck it out from the top and you are golden with no risk to stripping the drain bolt or having a leaking crush washer.
Senior Member
Joined: Nov 2009
Posts: 660
Likes: 48
From: napoleon ohio
Year: 98, 00, 01 and another 01
Model: Cherokee
Engine: both 01 jeeps have viper coil pack
I believe the drain pan bolt is 14 mm and when you drain the pain you will have about 4 quarts to replace.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Seems you are in great hands. Yea I wouldn't bother with the screen. Agreeing with all above. Since it all wont drain you can do your first now, then just repeat with oil changes while you'r there anyway until the fluid looks nice. That's one angle anyway. Myself I went with breaking my cooling line on lord knows what and pumping it all out on the road, emptied within walking distance of home. Ether way works.
Any suggestions on mileage intervals? I thought I read to drive at least 100 miles before repeating the cycle. I’m seeing also some suggestions on a few thousand in between. It’s going to be pretty dirty the first go around. Also, a suggestion on what type (brand) of dex/Merc to use the last time that will end up staying in there for the longer term.
Trending Topics
Senior Member
Joined: Mar 2016
Posts: 621
Likes: 9
From: Oklahoma
Year: 1992
Model: Cherokee
Engine: 4.0L L6 PowerTech (stock)
I did it all in one go when I bought my 1992 automatic a few years ago. I dropped the pan and changed the filter. I had to unbolted the dip stick tube/fill tube from the block instead of removing it from the pan because the tube was stuck in the pan and I didn't want to break that o-ring seal and leak. I filled the pan from the tube. I had someone start the vehicle with the oil cooler out line going to a bucket while I was pouring into a funnel in the fill tube until the fluid coming out of the oil cooler out line came bright red. I had her kill the engine, then adjusted the fluid level over a couple of weeks of driving. I had to add more fluid than the dip stick shows, but that was likely because the transmission never had been changed and wore from older fluid.
The old filter/screen didn't seem to be dirty. If you are worried about leaks, then don't mess with dropping the pan at all. I did use Dex II?/Merv V?, but all of the manuals state A.T.F.4+ should work. I think that the original specifications fluid was cheaper anyways... So between price and so many on the internet I guess that you should go with the old fluid. Who knows whether it isn't just A.T.F. 4 rebadged anyhow.
The old filter/screen didn't seem to be dirty. If you are worried about leaks, then don't mess with dropping the pan at all. I did use Dex II?/Merv V?, but all of the manuals state A.T.F.4+ should work. I think that the original specifications fluid was cheaper anyways... So between price and so many on the internet I guess that you should go with the old fluid. Who knows whether it isn't just A.T.F. 4 rebadged anyhow.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,577
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
CF Veteran


Joined: Jan 2017
Posts: 3,402
Likes: 394
From: Connecticut
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0
A significant concern is that those pan bolts can strip the transmission threads VERY easily. So IMO they either have to be removed periodically and CAREFULLY re-tightened or NEVER touched.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,577
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Replacement bolts with new crush washers can be had at most neighborhood parts stores.
CF Veteran


Joined: Jan 2017
Posts: 3,402
Likes: 394
From: Connecticut
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0


