Since I recently bought my Jeep I have been reading on changing the tranny fluid. There seems to be many opinions. My 98 with the AW4 has a little over 198k miles. Should I do a flush and if I should how would I go about doing that. The fluid is at perfect level and is brownish red. Shifts perfectly through all gears. Should I also change the transfer case fluid and diffs because I doubt they have ever been changed. They are at the correct level also.

 

A flush is not really needed. Just do a few drain and refills.. do short drive, drain refill, drive and do again until nice and clean. Remember to use Dexron III/mercon

As for the T-case why not do it also, wont hurt to have clean stuff.


Hows the radiator fluid looking nice and green or rust red? If rusty time for a radiator flush.

 

The PO had a new radiator and water pump put on. Nice and green coolant.

 

OK good on the radiator.. so just a few drain and refills will do the trans good.

 

x2

 

X3

 

X4

I did a drain and refill at every oil change for like a year. Slowly changing out the fluid like that seems to be the way to go. Now my fluid is a nice bright red.

 

Maybe I'll start doing that when mine hits 200k.

 

Yep, mine shifted much better after drain & fills. Started at 155k, pretty much done now at 175k.

 

did any of you run a cleaner agent through it with the flush and fill
or add an additive afterwards?
I use to run a product in my automatic in my Tacoma years ago
I am thinking about doing the flush and fill on my 01 with 89,000
not sure what PO had done to it, I'm the third owner
thinking of adding a tranny cooler and magnefine filter

 

Do not add cleaner agent. When just draining fluid you only get about 4 qts. of the 10 qts. out, that's why you drain and refill several times. You will never get all the cleaner out the first time and will probably do harm running it that way. When a shop does it they can hook up the in/out lines up to a pump and flush the whole system at one time. Additives are not needed for a correctly operating tranny. The AW4 is probably the most trouble free tranny of any model vehicle I have ever had. The only problem with it is the jeep system of keeping fluid cool so adding a auxillary tranny cooler will never hurt a rig.

89K miles is just a baby. First tranny drain and fill, add a drain plug to pan if it does not have one. Makes drain/fill much easier, I dont change filter everytime unless I see something in fluid that warrants dropping the pan, which I never have on my jeep in 325k or so miles. Or you can get a pump vac like I have that you just stick the hose down the filler tube a suck it out and fill.

 

Why wait??

 

I used to work at an automotive shop and did many trans flushes. We put in a cleaner, flushed out all the old fuild while replacing with new. We had a machine that did this. Then added a contioner. Brought many transmissions back to life that way. I would never do just a drain and fill. Average transmission hold 12qts of fuild. You drain around 3qts when dropping th pan. Thats only 25% of the fluid replaced. You wouldn't replace only 25% of the engine oil at time. Would you?

 

This is the way to NEVER DO ONE!!! Usually only places these are found are at the quickie oil change places.


Almost 100% guarantee it will be the wrong ATF for one thing. Then if you think it really needs to be cleaned and a new filter go to a transmission shop and have it done. The drain and fill several times should work just fine for you.


You ask about the differentials also, do pull the covers and drain the fluid then check for any gear wear. Clean well and wipe out the carrier replace covers. This should be done at least once a year unless you are in water or mud then more often.

 

From what I have read the AW4 doesn't like tranny flushes and that has killed quite a few.