Hey y'all.
... 99 XJ, 4.0L, AW4 trans.

Quick question. I've attempted to look this up on the interwebs... but not finding an exact answer to this question.....

I have a fairly low mileage XJ, with only about 110K on it and all drivetrain is original to the jeep.
I work from home most of the time (not due to the plandemic)....So.... I don't put more than maybe 4-5K a year on it at the most. The increase due to moving to a large city so things are more spread out. I change my engine oil on schedule. But the trans got fresh fluid about 4 years ago when my XJ joined the family.
Since then, I've put a whopping 12K on it in total.
My question and concern is this.... I know that typically trans fluid is changed ballpark every 30-50K.
Is this stuff hydroscopic or anything else that even with much less actual use, would cause the fluid to break down where I should change it more often? Because of the extended time and lower miles/hours of use?

it shifts smooth now... and fluid colour doesn't look burnt... but just because it doesnt look burnt doesn't necessarily mean that it's not breaking down.

Cheers!

 

Well it depends.
So in my '01 FSM they break down the maintenance schedule into 2 categories.
Schedule A and Schedule B.
Schedule A appears to be for normal driving.
There is no description
I think Schedule B is more a Severe Duty schedule and is described as this:

SCHEDULE “B”
Follow Schedule “B” if the vehicle is usually operated
under one or more of the following conditions.
† Frequent short trips driving less than 5 miles (8
km).
† Frequent driving in dusty conditions.
† Frequent trailer towing.
† Extensive idling.
† More than 50% of driving is at sustained high
speeds during hot weather, above 90°F (32°C).
† Off-road driving.
† Desert operation.

So with Schedule A it is done at 30K intervals.
With Schedule B it is done at 12K intervals.

What little I do drive is short trips.
I just swap mine out every other year.
And there is probably only about 6K on it.
We have a drain plug and for the price of 3.5 quarts screw it.

Oh and for the record.
The recommended tranny fluid for the AW4 in my '01 FSM is DexIII/Merc.
LOL.

 

Thanks Ralph... that puts mine at just about time...
I think it's the same fluid for my 99..

I try to get mine up on the highway whenever I can...to help keep it cleaned out. Not always possible..but much as I can.

So you just do a drain and fill. How many quarts do you get out of yours? Memory seems to tell me that the AW4 actually holds quite a bit.

 

When you just drain through the drain plug about 3.5 quarts give or take.
As has been said a zillion times unless your pan is leaking and you want to put a new gasket in there no reason to drop the pan.
It is not a filter but a screen.
Be careful torqueing in the drain plug. You don't want to strip it.
Also you should find a washer in there. At least I did in my '00.
But it really isn't a washer. It is what they call a crush washer. Flattens out when torqued in.


I will probably catch some flack for this (LOL) but I have just been reusing the drain plug and the crush washer.
Have changed my tranny fluid 4 times in 8 years and have yet to have a problem so......

 

Err on the side of "more often", reather than less. It's not just the mileage. Age counts.

If it's an AW4, it's Dex/Merc. All years. Ignore any auto store advice to use ATF+4.

On the drain and fill, if you want to get it all at once, see my sig, #3.

 

Thanks guys....
When it comes to changing fluids in my vehicles, I tend to do it pretty religiously. And my vehicles tend to last longer... hmmm... mr. obvious... I think there's a connection.. LOL...

Yeah... will be doing the trans fluid soon.
There's no slipping, and didn't appear when I bought my XJ years ago now, that the PO missed those changes either which is a very good thing.

I was aware that it was a screen and not a filter.....but will be careful on the re-torquing of the drain plug. Will have to check and see if mine has a replaceable crush washer.

Question..... does just that drain and fill of about 3.5 quarts really change enough of the fluid to keep it healthy long-term?
I don't mind doing either that or the full drain....whatever is best.... I mean, doesn't matter how you slice it... even if the cost per quart is expensive...it's nothing compared to the cost of a new or rebuilding the trans.

 

If it is done regularly, probably so.

If it's been neglected and you are in recovery mode, no, not in my opinion. Some suggest doing several to flush it all out. I prefer the method in my sig #3. It flushes it all out.

 

That is why I do it every other year.
I want to say the the tranny takes about 9 quarts total.
But from what I understand the only way to get it all out is to drop the tranny and empty the torque converter.
Dropping the pan is really going to let you get anymore out.
If you are really that concerned you can do the flush where guys put the return line in a bucket with the Jeep running and just keep throw fluid in there till they are satisfied.

 

As said earlier, the TC retains some fluid so you can't easily drain it all out. "Standard practice" on my Acura (for example) is to do a 3x3 drain and fill. I get about a 3rd of the fluid out when I drain. Then top off (about 3 qts). Drive a few days to mix it all up. Then drain and repeat 2 more times. Good until the next interval.

 

Yeah.. I like that idea, but I don't have 2 other people that can assist with that right now unfortunately. But that's a pretty slick way to do it I have to admit. Thanks for sharing.
This is one of those times where as solid as the AW4 generally is.... makes me wish I had a good ole manual trans.

 

Glad I don't.
I am to lazy to be shifting all the time. LOL.

 

Well the trans seems to be in decent shape still... so I'm not trying to be overly **** retentive with it.... just like they say with oil changes... for the most part as long as you're putting the right weight...and actually changing it on time, then the brand, etc doesn't really play that big of a role.

 

Only time I hate shifting is in stop and go city traffic...then you just have to change the clutch out more often. And have a tired left leg by the time you get anywhere. lol

If I remember correctly... I think the AW4 in our old jeeps is a little beefier than the manual. Plus I think the stock gearing with the manual was a 3.07 if I remember correctly..and the auto was a little larger I think.

 

I think the AW4 is more robust than the AX5/15 too. More people have killed the manuals by using the wrong fluid than the autos by using the wrong fluid. At one point, the FSM actually said to use GL-5 which is harmful to the brass synchros. Even GL-3 shifts like crap.

 

Nah, See my sig, #3.