Cummins93

I did a disconnect fluid change to replace most of the fluid at once. Mine came out black with brown chunks. In went the cheap ATF. No complaints with 30k on it.

I want to say we put the non synthetic dex/merc spec 2 and 3 correct?

cruiser54

Regular old Valvoline or whatever Wally World has.
Best to get that "crappy " fluid out ASAP.

Rogue4x4

I just gotta add this...

...would you swap out your motor because the oil was dirty?
Why wouldn't you do a fluid change before replacing the trans?
LOAD THE CANNON!!!

BlueRidgeMark

This is a very stupid old wives tale that will not die, and even a lot of mechanics believe it. It's complete garbage.

If you go to Jiffy Lube and get one of their "power flushes", yes, you can screw up a transmission. But clean fluid is never going to hurt your transmission.

See my sig, #3.

BlueRidgeMark

Correct.

cruiser54

So much fail on OP's part.
Can we save him/her from the jaws of greedy
trans builders?
We all know the truth.

dave1123

You can generally tell the health of a transmission from the debris in the pan. That light gray mud-like stuff is friction material from the clutch plates and the tiny slivers of steel on the magnet are from the driven clutch plates. If the steel is just mud-like with no actual slivers, that's normal wear. If you find slivers, the plates are scoring just like brake rotors. Not good. When that stuff gets bad enough to start bypassing the magnet, it will wear the servo spools and bearings. It also plugs the ports in solenoids. You need to get that stuff out of there occasionally by changing the fluid and filter. 35K to 50K is about the right interval in my opinion.

cruiser54

Drain and fill every 30,000 miles in normal service. 15,000 miles postal delivery, taxi, or towing.

Cummins93

Is that interval greater when not doing the drain and fill method? I.e. having a helper work the ignition and breaking the cooler line open to pump the fluid out.

cruiser54

I guess. I'm just quoting factory recommendations.

Basslicks

OP... I'm no expert, but when I did my 4wd conversion, I took an AW4 transmission believed to be "inoperable" out of a 96 XJ. The transmission fluid in it looked like used motor oil though it was definitely burnt transmission fluid that had never been changed. Under the advice of the gurus here, I drained the black nasty out of the transmission and filled it with DEX/MERC as is being said here.... voila. Transmission shifted perfectly. Better than the 2wd transmission that I had just pulled, in fact.

If you're preparing yourself for having to change the transmission anyway.... what's the harm in trying what people are saying here? If it works, you saved yourself a ton of money. If it doesn't, then you can brag that you were right and go right along and spend a couple grand for a replacement.

Seriously man, just try it. I bet it'll work.

Russell707

Basslicks

Dexron/Mercon can be had anywhere. Walmart, autozone, advance.... gas stations.

I can't remember exactly how many quarts, but I want to say it was 4. If you have an owner's manual, it will be in there. FSM will have it too. Haynes or Chilton's manual also lists it.

Geek

Change the fluid and while you are there a new filter wouldn't hurt.

cruiser54

It's a waste of time and money to replace the screen in an AW4.

The only reason to remove the trans pan is if solenoids fail or the gasket leaks.