Why did my transmission puke?

I was driving home on the interstate and while getting off my exit ramp something in my transmission went out and puked fluid everywhere. It was dripping out of the front of the bellhousing when I stopped to look at it. Pulled the transmission yesterday, figured it was the input seal, didn't look like it had gone bad nor did the torque converter. The vent on the top of the tranny was fine, wasn't wet or anything. Was running at normal temps like always on the highway when it puked. Any ideas? Its out of a 93 and haven't had any problems until this after swapping it in last year.

My 1st guess is that you probably filled it to the "Full when Hot" when cold.

It's pretty common for folks to do this.

ATF expands rapidly. The distance between "Cold" and "Hot" marks is about a pint and it will fill that volume when just driving. Fill it to "Full when Hot" level when Cold, and the same expansion will happen and sometimes pukes out the vent behind the TC.

Also, if you have enough of an over fill, the fluid can foam up and it won't work correctly.

-Ron

The top of the bellhousing didn't look like it had been wet. Odd that it would do it driving home and not on the way to the race or the last two weekends when I went wheeling. This happened on a hour 15 minute drive on the way home from watching a race.

The vent is behind the torque converter on the pump housing a few inches above the input shaft.

Hard to say, why it decided to puke fluid then. If it was hot, overfull, and pointed down hill, it'd probably puke a bit.

Right, that vent didn't have any fluid around it. I'll keep looking it over. I certainly don't have a clue anymore.

Your transmission tube vent valve is probably clogged/stuck closed. This would prevent the air from escaping when the fluid expands, and thus pushing tranny fluid out. For my 98 the transmission vent valve is located on the upper firewall of the passenger side. Hope this helps.

That could be the case. According to another thread I found on the Forum, the vent tube is on the pass side firewall. And I found a system fix on the web about fluid being puked out the dipstick caused by the vent being clogged.

Good info!

My 88 started doing the same thing and I just figured it was getting to hot and dumping fluid out of god knows where, so I disconnected the tranny lines running through the radiator and installed a stock tranny cooler from the junk yard off an XJ with the towing package and the issue went away completely right after that.

thanasi85 said:

My 88 started doing the same thing and I just figured it was getting to hot and dumping fluid out of god knows where, so I disconnected the tranny lines running through the radiator and installed a stock tranny cooler from the junk yard off an XJ with the towing package and the issue went away completely right after that.

Click to expand...

I have a giant tranny cooler on it now in front of my efan running inline with the radiator cooler.

Is there a way to clean out the area where the vent is without sending all of that trash into the tranny? Could probably use a new vent fitting anyways.