Ok so I bought this jeep last Sunday running through all the fluids and fixing everything I come across. The tranny fluid is not horrible but I would like to do the 4 qt change? I am unsure if they kept it dex/merc or if they addded atf+4 I plan on putting dex/merc in it will I run into problems if they did infact change to atf?

 

ATF 4
Oh, hey man! Any luck with windows?

 

I just did this myself. I had originally put in 4 qts of ATF+4, then ran it about 1000 miles. I drained about 4 qts last night and put in another 4 of Dex/Merc III. It ran great last night for about an hour, I'll keep an eye on it and let you know if anything changes.

I have no idea what was originally in the transmission when I bought it, it was completely black and watery.

 

Yeah it was the motor that was bad went and picked one up at the junkyard.
Awesome thanks Ill hold off and wait to hear from you or Ill pm you later.

 

ATF+4 is expensive compared to dexmerc, but im not sure you reasoning besides that, on why you would run dexmerc...aw4s run ATF+4, not dexmerc, I wouldn't take the risk of trashing my $2,000 transmission by running the wrong fluid because of another $15 at the register...

 

Well first of Dex/merc and atf+4 are the same price at most place. Second AW4 was originally setup on the dex/merc and in a later TSB they changed it to say that ATF+4 could be used in its place. I am assuming you didnt read the actual post and just read the thread title. My question was not that I prefer to cheap out and use Dex/Merc as you implied but that I do not know wheter the previous owner changed the fluid out with the original dex/merc as specd by chrysler or followed the TSB and changed it with ATF+4. My question is if they did use atf+4 or dex/merc and I changed it with the other would there be any adverse effect when doing a service change of 4 qts. as in not the full 8+ quarts and filter change.

 

A mind is a terrible thing to waste.

 

D/M is what is recommended for the AW4. Also, any place I've seen, ATF+4 is more $$, because it must be blended from grp III basestocks to be licensed.

 

I understand that! I WANT TO PUT DEX/MERC IN. I am worried that the previous owner may have had it replaced with ATF+4 at some point in time. I am asking if that is the case am I better to just drain the entire tranny and replace filter. Or is there no adverse effects of adding Dex/Merc if they did put ATF+4 in it.

 

Just put the dex/merc in it. You won't get any more ATF out by pulling the pan and filter than you will with the drain plug anyway.

 

Thank you.

 

dex/merc for sure

 

This ^

You have to do some kind of flush to get every drop of fluid out (don't get a pressure flush though!)

I have driven my Cherokee several times today and it's still doing great. I've been up to freeway speeds and everything in between (well, no wheelin'...)

 

DexIII/Mercon = ATF3
Factory fluid for XJ AW4, NP231J, NP242J...ATF3

 

If by ATF3 you mean ATF+3, then no. ATF+3 superseded to the current ATF+4, and they are both HFM (highly friction modified) fluids. Different than Dex/Merc.