Interesting. And you were wrong about flushing, too!

 

Id go dex/merc as well

 

Really? How so?

 

In my opinion if the trans was built using atf+4 just keep using it. A lot of manufactures these days share transmissions and use their own kind of fluid. It is more important to keep the fluid brand and additive package consistent to keep the clutches shifting properly and the torque converter engaging smooth.

Heat degrades the fluid more than time. If your transmission temperatures are generally low ie, mostly freeway driving, cursing then go 50k. Heavy towing, crawling, city driving max 30k interval, and an add on cooler would not hurt.

Just my 2 cents.

 

I'm kinda with kbeam on this one... Don't mix the fluids. Use the ATF+4 you have in there until you have a chance to do a complete fluid change with Dex/Merc. But, it should be changed over to Dex/Merc ASAP. So, I'm kinda agreeing with both sides here I guess.

 

Ok...but its not like it takes much longer to completely change it out.

 

A related question is whether it's possible to tell what's already in there. Most XJs have been through multiple owners and it's not always possible to get the service history to see if ATF+4 was installed at some point in the past.

 

i would say that for a large majority of us, changing the transmission fluid is part of the things we do as soon as we get a new to us vehicle. Maybe the jeep had atf4, but its getting fresh dex/merc asap haha

 

 

No 1; No the steps are the same.
No 2; Imo no because it's just a screen from what I've read. You shouldn't need to drop the pan at all.
No 3; No this is the best method, as other members have said the AW4 likes DEX/MERC so you should switch. The only reason why I said to use ATF+4 is simply because mixing fluids is bad. With this method you're not going to be mixing the fluids together. If you feel comfortable doing it this way you should do it.

You've got our opinions (that's all they are) it's up to you to decide how you want to change the fluid and what fluid to use.

 

Sweet. I wasn't sure how to go about switching from ATF4 to D/M, and now I how. I'm glad to know I that I can use this video as a visual guide for when I get to the point of a fluid exchange. I will definitely do this instead of keeping the ATF4 as stated earlier as it really isn't that much more effort. Thanks a bunch!

 

I know I'm late, but I finally got around to doing the complete fluid change on my 99 XJ's AW4 1 week ago (ATF4 to DEX/MERC Automatic Transmission Fluid). I had noticed some red transmission fluid around all of the bolts and around the gasket/seal, so I ended up dropping the pan and just doing the filter/screen anyways, even though the filter/screen wasn't really necessary.

Thank you all for the intel. I used a very slightly modified version of BlueRidgeMark's method for a complete fluid change from ATF4 to DEX/MERC. Here is my process for anyone who is as nervous as I was when I did this. It may look like a lot, but it's not that difficult-- I just wanted to be thorough.

HOW TO DO A COMPLETE FLUID CHANGE (SWITCHING FROM ATF4 TO DEX/MERC)

OVERVIEW
Part one covers draining the pan fluid
1a covers draining the transmission and replacing the bolt as a reference for torque specs I guess
1b covers draining and dropping the pan (if you need to redo the gasket like I did)
Part two covers the flushing out the rest of the fluid.

MATERIALS

NECESSITIES

• 14 mm socket
• Torque wrench that works between 5 and 15 ft-lbs.
  • I used a screwdriver type attachment for socket since I didn't have a torque wrench on hand, and I've been OK 100 miles later.
• Replacement drain plug and gasket
  • I ended up just replacing my old ones, and it has not leaked so far
• At least 2.25 gallons of DEX/MERC III (I used 2.5 gallons total because my fluid was still red and wanted to make sure I had only DEX/MERC in there)
  • The AW4 transmission has a capacity of 8.2 quarts
  • Having two gallon-bottles and a quart-bottle may help get a more precise amount
  • I used Valvoline DEX/MERC Automatic Transmission Fluid as it was the only DEX/MERC III-compatible fluid available locally.
• Funnel
• Hose cutter or pliers
• 3/8" to 3/8 " barbed fitting
• 3/8" hose
• Two 3/8" hose clamps

IF DROPPING THE PAN

• 10 mm socket
  • For the 19 pan bolts
  • Also for the 4 filter bolts if you've decided that you want to replace the screen
• Block of wood (to protect dipstick tube when getting the dipstick tube flush)
• Sledge Hammer
• Brass wire brush and razor blade to remove persistent pieces of old gasket/RTV

TROUBLESHOOTING

• For stripped threads around the pan:
  • A drill
  • ¼” drill bit
  • M6 x 1 helicoil kit
  • Tap wrench (I used a ratcheting T-handle tap wrench)
  • Red Loctite

PART ONE - DRAINING THE FLUID IN THE PAN

1a - IF NOT DROPPING THE PAN

1. With a drain pan ready underneath the transmission, loosen the 14 mm drain plug bolt
2. When the flow has just about stopped, empty the drain pan into a container where you can estimate how much you drained out. I used a gallon jug and a 2 liter bottle since I got more fluid from dropping the pan.
   • Mine drained about one gallon and additionally half of the 2 liter bottle when I took the pan off, so I put in 5 quarts.
   • Without dropping the pan, you probably will get between 2.5 and 3.5 quarts of fluid. If you jacked up the front side, probably closer to 3.5 than 2.5. But these are just estimates from other threads I've read, so your mileage may vary.
3. Torque the drain pan bolt to 15 ft-lbs or hand-tight.
4. Add as much fluid as was drained.

1b - DROPPING THE PAN (OPTIONAL)

1. Pop the hood and remove the dipstick from transmission
2. With drain pan ready underneath the jeep, remove the 14 mm drain pan bolt from transmission.
3. Once draining has slowed enough, remove the 10 mm bolts (there are 19) around the transmission pan and pull off the pan
   • It helps to rotate back and forth to remove from dipstick tube, but mine was easier likely because it had been rebuilt
4. Clean transmission and pan surface. -- Mine had RTV from when it was rebuilt, so I used a fat brass wire brush I got from home depot and a razor blade (carefully) to remove it.
   • (Optional): remove 10 mm bolts (there are 4) of transmission filter and replace filter and bolts. They take 7 ft-lbs of torque, but I didn't use a torque wrench, so I tightened as much as I could with one hand and a screwdriver-type tool
5. Use brake cleaner to clean off the pan. Don't forget to clean off the two magnets in the pan
6. Put gasket on pan (only goes on one way)
7. Feed bolts through pan and gasket to start them before replacing the pan
8. Line up transmission so that the pan goes through the dipstick tube as close as you can get to flush (it will not remain flush when you start lining up the pan with bolts, but as long as it stays in, we can use the sledge hammer later to get it flush).
9. Just barely start the bolts in the transmission
   • I started from the end diagonally opposite the dipstick tube and then went straight across so it was easier to line up. It helps to push up on the pan when getting the bolts in on the driver side. This was probably the hardest part.
10. Once all the bolts have been started, tighten to 65 in. lbs. (5.42 ft-lbs) I didn't have a torque wrench on hand, so I just tightened until hand tight using a screwdriver type attachment.
    • If your bolts won't go in all the way, becoming difficult to turn before they're fully in, make sure to clean out the threads on the transmission.
    • If your bolts went in but won't tighten, your threads are likely worn. A M6 x 1 helicoil kit will save you from needing to get a new transmission here.
      • Make sure the helicoil insert fits around your bolt.
      • Drill straight into the hole with the stripped thread on the transmission using a 1/4" drill bit.
      • Line up the tap tool as perpendicular to the hole as you can get and tap into it using a tap wrench. (It should be somewhat easy because the pan is soft as aluminum, but if you feel too much resistance, turn back about a quarter turn when you feel it, then turn forward again.)
      • Once you've gotten at least enough thread to get the helicoil definitely past flush, take it out.
      • Apply some red Loctite around the outside of the helicoil insert
      • Put the helicoil insert into the threaded hole until about half a turn past being flush. I was able to get my drill to bite the tool and spin the helicoil in.
      • Your thread should be repaired once this is done.
11. Go around once more and recheck torque or tighten again until hand-tight with screwdriver.
12. Put in new drain pan bolt with gasket and torque to 15 ft-lbs or hand-tight. (When I was ready for this, my amazon package came empty-boxed, and I had to drive that weekend, so I re-used my old one, which has not been leaking).
13. Back to the hood, place a block of wood on the transmission dipstick tube.
14. Give the block of wood resting on the dipstick tube a few good whacks with a sledge hammer and check underneath the jeep to make sure the tubing is flush with the pan's piping. If not, keep hitting.
15. Remove the wood block and add as much fluid as was drained. To get an estimate, I emptied the drain pan into a gallon jug and a 2 liter bottle on top of that. Mine drained about one gallon and additionally half of the 2 liter bottle, so I put in 5 qts.
16. Check for leaks.

PART TWO - FLUSHING OUT THE REST OF THE FLUID

1. Get a piece of 3/8" hose, 3/8" to 3/8" barbed fitting, and a 3/8" hose clamp ready.
2. With a gallon jug and drain pan ready underneath, cut the transmission return line at the fat hose portion.
   • On the 99 XJ at least, this line is the one going to the back of the transmission.
   • I just used pliers to make the cut, being careful to cut a straight circle
3. Put in barbed fitting on side towards front of chassis then put a hose clamp around it.
4. Attach 3/8" hose to barbed fitting and point the free end into a gallon jug
5. Have a friend turn on the jeep and drain until the jug is nearly full or the transmission starts sputtering, at which point you turn off the jeep.
6. As much as was drained, add back
   • For me, my transmission started sputtering when I had 3/4 of the gallon jug full, so I added 3 qts and then drained 1 qt again to flush out 1 gallon just so I could keep better track of everything.
   • Repeat until you've drained out a total of 8.2 quarts.
     • Since I had some fluid to spare by getting 3 gallons instead of 2.25, I drained out a total of 2.5 gallons, which was easier for me to estimate than 0.2 quarts without the marked quart-sized bottle.
7. Remove the 3/8" extension hose and reconnect the chassis-side of the stock hose to the transmission pan-side via the barbed fitting
   • Clamp down the transmission pan-side of the barbed fitting.
   • Check for leaks around both sides and clamp tighter if necessary.
8. Start the car and drive around for about 15 minutes, and when you get back to where you're working, go through the gears a few times.
9. Check the fluid level now that transmission is warm
   • Top off as necessary.

 

Just to add to the discussion, my 2000 Cherokee Sport has the AW4 transmission and my FSM states Dextron IIE/Mercon is the recommended fluid. It also states not to use Dextron II because clutch chatter may result. It says nothing either way about ATF+4. It also does state that the fluid is red to differentiate it from engine oil, but the color is not permanent and may darken over time. This is not an indication of the fluids condition and proper change intervals should be maintained.

The FSM also has data for the 30RH used with the 2.5L engine and that uses ATF+3. ATF+4 superceeds ATF+3 so I assume that's what you'd use in the 30RH.

Both the NV231 and NV242 are supposed to use "Mopar Dextron II or ATF+3, type 7176". In that case why not just use whatever you use in the transmission?

 

Pardon me for not reading the whole thread. The AW-4 is awesome and nearly indestructible. If it's ugly, or not Dex/Merc III or equivalent, just change more often, maybe with oil changes. Drain what will drain, little more than 1/2?, add a similar amount and "tune" to the dipstick, and just let the detergent in the fresh fluid work away at any crap. Soon enough it will be pretty, pink, fluid with very little work or expense. I'm not sure myself about stories of "power flushing" or any flushing dislodging crap and causing major headache. I'm just practical and maybe a bit lazy/cheap, and like the idea of just letting the detergent in the Dex III do it's thing.

Do note it only has a screen, not really a filter.

 

I've used the pump out method blueridge recommends on 4 aw4s in varying conditions. I have no complaints about using the cheap stuff. When I start pushing 300+ hp through one I'll tell you how it turns out.