Tranny leaking fluid from where?

My tranny is starting to leak fluid out the bell housing area onto the exhaust. It first happened on the highway coming back to Utah from Denver. I was coming down a long hill (about 6% grade) going about 80 and saw a huge cloud of smoke coming out the back. I immediately pulled over and popped the hood, everything looked good so I looked underneath the jeep and there was tranny fluid everywhere. I was able to get it to a shop where we added fluid and after letting it cool down I drove the rest fo the way home with no drama.

The next time I was on the highway coming down a long hill (about 4% grade)doing about 80 again when I saw the same thing out the back window. This time I just slowed down and was fine the rest of the way home.

The last time I was coming down a gradual hill and doing about 70 and saw a light amount of smoke trailing behind me so I just slowed down again.

If this keeps up I'm not going to be able to drive on the freeway at all soon. Around town the tranny shifts fine and doesn't leak fluid at all. The fluid is a nice red color, so I don't think its overheating. Relavant info would be it is a 96 with 31" tires and stock gearing, automatic, of course.

Anyone have any ideas?

Just taking a WAG (wild arsed guess) I´ve never seen the front of the AW4 leak (but anything is possible).
Have seen the tranny cooler lines under the radiator leak and spray all down the bottom of the motor, all the way to the cross memeber.
Have also seen the rear main seal, for the motor seep into the bell housing and build up, until it drips when the motor is stopped or parked on an incline.
When I have a main bearing seal, thats seeping and the buildup is dripping on the cross over exhaust pipe, I drill a hole in the bottom of the bell housing, thread it and put in an extended nipple so it drains a little lower than the exhaust pipe. Have also bent the dust shield for the bell housing out a bit, to wash out the inside of the bell housing at the quarter wash (gets rid of the buildup, sludge and dirt).
If the main seal is seriously leaking, like a quart every 1000 miles or so, the only thing that will help, is a new seal and new seals have habit of not lasting very long. Due to play in the crank bearings.
A good functioning crankcase ventilation system, often helps, limit oil loss from the motor.
If the fluid is coming from the front of your tranny, probably the only thing that will help is a new seal and bushing. Have seen flex plate bolts loosen and cause front seal seeps.

I'm sure its not the main seal as the fluid dripping from the underneath of the jeep was red, but I hadn't thought of the cooler lines leaking somewhere and spraying underneath. Are they high pressure lines or low pressure?

There is some pressure in the lines, but not really what I´d call high pressure. I´ve seen a mix of tranny fluid and motor oil at the bell housing. The tranny lines don´t often cause smoke, and if they are leaking much there are drips on the ground under the radiator. What you have may be a combination of seeps.
When the tranny lines are seeping there is often what looks like a smear mark on the motor pan. And dust and wet oil on the tranny line connectors under the radiator.

Israel said:

My tranny is starting to leak fluid out the bell housing area onto the exhaust. It first happened on the highway coming back to Utah from Denver. I was coming down a long hill (about 6% grade) . . .

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I had the same thing happen to my '96 going up to the Sierra's last year in 98* weather. The only difference is that my jeep overheated the whole way up there. It looked like red (not burnt) tranny fluid dripped out of the bellhousing and sprayed all over the tranny. I had to add about 12 oz. of tranny fluid back in, wiped the undercarriage all clean, and it never happened again. I'm interested in where that fluid might have come from. I just assumed it was from the boiling over, because the fluid was not burnt and tranny still runs fine.

If your seeing a cloud, i wouldnt call it a seep. You may want yo check the front pump seal on the tranny, mine went out about 6 months ago and i saw the same cloud of smoke trailing behind me. Its a pain to get to cause you gotta drop the tranny but its a simple R&R procedure. Either way, that sounds to me like a likely culprit. keep us posted.


Mike

Yep - front pump seal. Since you are probably cruising at higher RPM on the freeway, you will develop more pressure in the pump, and that would make a failing seal more apparent.

Good news/bad news. Good news - you don't have to tear the transmission to bits to change the seal. Bad news - it has to be separated from the engine far enough to remove the torque converter (which can be left bolted to the flexplate, since it's a slip fit into the tranmission anyhow) and get to the front pump.

NOTE - check the torque converter hub for wear when you get in there - make sure there isn't a "seal ring" on the mating surface, or a new seal will be a waste of time. There may or may not be a repair sleeve if there is trouble, like you might find for the front main on the engine...

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