carbuff

So, I changed the fluid in my 231 TC today. Its a 2000, 4.0, aw4, 4wd. Both of the plugs came out fairly easily once I bought the correct 10 mm hex socket. So, the first thing I notice when I unscrew the fill plug is a very slight puff of air like there was some pressure built up inside. I thought the vent prevented this, maybe its plugged? Then oil starts dripping out like it was just slightly overfilled.I figured that the oil was warmed up from driving to the advanced and back (2 miles) in 4wd and the xj was parked in a very slight incline as my driveway is a tiny bit inclined. I also noticed that the fluid looked blackish with a red tinge to it. The inside of the plugs were spotless and it looked clean inside. This is where it gets a bit strange. I filled up my squeeze bottle with a qt of fresh dexIII and proceed to fill. Just as I get the last bit in, it starts to dribble back out. It was full. Checked it with my finger and sure enough its full. 1 qt.? I was like wtf? I had read from 1.5 to 2 qts to fil the 231. I poured the old oil from my catch bucket into the empty qt bottle and it filled it . So, 1 qt came out and 1 went in. Should I be worried about this? The 4wd worked smooth and quietly all day today. I will probably check it again in the spring but has anyone else come across this?

CCKen

The 231 capacity is 2.2 Pints.

Roler

In regards to what you stated: its difficult to significantly overfill a TC, simply because it will pore out of the fill hole. When things heat up, it will expand, and that together with the slight incline of your driveway, will make it come out. Dont worry about overfilling...
And full is full, if 1 cam out, I'd say: fill with 1.
If its that black, you might wanna re-do this again after a bit of driving around. After that it should be pretty good for several K's.

salad

1 quart on an inclined driveway is all you're going to be able to pack in there.

CCKen

Why make a church out of a **** house.

The OP said: I had read from 1.5 to 2 qts to fil the 231.

Just giving him the factual data.

Read my signature.

salad

You must need another coffee if you can't tell I'm agreeing with you lol

CCKen

Another coffee....?

Heck, I'm not even done puking yet.

carbuff

Thanks guys. 2.2 pints. Sounds about right. Im probably gonna change it again in the spring. I used the dex/merc stuff which is for vehicles that take dex 2 or 3. Is it ok to use the dex VI synthetic next time or should I stick with the regular. Is the vi compatible? And, is the vent a 2 way vent? Like is it just a hole in the tc with a hose on it and a plastic cap to keep debris out? Or does it have a 1 way valve or something.

CCKen

There's no need to use Dex VI, just use the same ATF you use in your tranny so there's no mixup between the two.

The TC vent valve is an over-engineered POS. It's sort of a check valve. I trashed mine and used a front differential vent in its place and relocated both the AW4 vent and the new TC vent further up against the firewall for easy access. See pics.

If you want to relocate your TC vent, you'll need to get a front differential vent from the dealer, a 24" length of 5/16" ID vacuum hose, and a 5/16 X 5/16 OD barb coupler from an auto parts store or a big box hardware store.

Remove the original vent valve and trash it. Insert the coupler in the TC hose, insert the new vacuum hose on the coupler, then route it up to the top wire loom against the firewall, cut it to length, and secure it with a cable tie (see pic).

You can do the same with the AW4 vent by reusing the original vent and use a length of 1/4" ID vacuum hose and a 1/4 x 1/4 barb coupler.

TC vent valve and its mount:



The POS TC vent valve:



View of both AW4 and TC vents relocated:

carbuff

Thanks for the pics. So it is possible for the tc vent to go bad and allow pressure buildup in the tc. Your new vent locations are similar to where the factory has the extended line and vent for my front axle on my 2000. Looks like another project for the spring. The list is getting longer. LOL.

CCKen

Here's another change you may want to consider for your next spring projects. Replace the internal wrenching hex plugs with external wrenching plugs. The pic gives the part numbers, etc. I've been using these for some years now and have had no plroblems. They work on the NV242J and the NV231J gear boxes. NAPA supplied.

salad

Nice, I'm going to have to grab those plugs. Thanks for the P/N

Tony_SS

Great, thanks Ken.

Roler

those externals are great!