It's about due for an ATF exchange on my 99 XJ with the auto trans....
Professional or personal experiences wanted...

Do you think it's safer to just do a drain and refill and a include new filter? I know that doing so only replaces a portion of the fluid....but I've also heard stories, not just with Jeeps... that doing an actual flush and you end up being able to replace most of the fluid (or a least a lot more than just a drain and fill)..... that somehow you can run the risk of "disturbing" things and it ends up causing problems either with causing leaks or internally with the gears or the TC.

experiences... pro's and con's would be helpful... Thanks

 

Well, 99 xj trans filter is more like a screen than a filter. If its been a long time, probably wont hurt to drop the pan, replace the filter and gasket and dump in some fresh dexron3. I dont trust those flushing machines at some shops, so im content to do multiple fluid changes over a short period of time. AW4 trans has a drain plug so after the initial filter change and service, I'll pull the plug and refill with roughly 4 more quarts for the next 2 or 3 oil changes (or do sooner if you run long oil change intervals). Cherokee trans is one tough little b*tch, i wouldn't worry about causing problems because of a fluid change (unless you're wheeling it hard or abusing it). Otherwise, regular maintenance, decent (and correct) fluid, and you'll get plenty of miles out of that trans. I'm at 179k with mine and still shifts great.

 

Drain and fill, or allow the trans to pump out the fluid into a bucket and fill. You can get more out using the pump method.

Don't worry about replacing the filter (screen).

 

thanks for the response... I was leaning towards that, but with some of the stories I've heard with the flush machines... I was thinking...hmm.. not gonna risk it. My trans shifts exactly as it should, so I don't think there are any unknown internal issues with it.

I was planning on dropping the pan and doing that replacement too at the same time.

Thanks.

 

From my experience talking to a lot of knowledgeable mechanics over the years. (I'm in the parts business so see and talk to professional mechanics all day) if your transmission is in good shape and the fluid a nice color then flushing is fine. The time you don't want to flush is higher mileage or badly worn transmission where the fluid is black or something. It's best just to leave those alone. I know Jeeps are different but my old Caravan went through 2 transmissions and died not long after flushing it when the fluid was jet black

 

I know there are several things that factor into doing a full fluid flush or just drain/fill with changing the filter/screen.
Mine, it's just at the point of changing.. but it also has 97k on the Jeep too. I don't think there's a problem with the trans. It shifts smooth, etc. I've fixed enough problems on this damn thing in the short time I've had it... if the trans is working good, I don't want to invite Murphy to join the party.

 

The screen doesn't need to be changed...

 

If something's working fine I usually do "light" maintenance. That means change it. Maybe do it again with the next oil change. The drain and fill method.
I flushed my heater core... didn't work out too good when I had a swimming pool on my passenger floorboard.

 

tbone - my bad.. the filter

and billyboy - yeah... especially if you don't have a pair of those blowup arm floaties laying around. lol.

 

The "filter" is just a screen. Same thing.

 

My 95 xj got a change at 260k? The fluid was black/brown chunky and smelled very burnt. I'm over 270k currently and I use it to plow. No issues yet. I used the pump out method with a friend working the ignition. I filled with the cheap dex/merc II/III non synthetic fluid.

 

Drain and fill only unless your pan gasket is leaking.

Use Dex-Merc III only. Have 4 quarts on hand.

 

I appreciate the response on this... I know it's just a routine maintenance item. One that I've done on vehicles before..... it's just that since I don't have direct knowledge of the service history for it, I want to make sure I go the safest route. I've already addressed a few issues that needed attention on this rig and am trying to get it under control. So didn't want to poke the sleeping bear of a good shifting auto trans.

 

Its an AW4, it takes a heck of alot more than a fluid change at 100k to hurt one.

 

well... while it may be true that the AW4 is built with similar reliability as the I6 4.0..... if not properly maintained, you can literally drive any reliable vehicle into the ground.