I smell oil, and see smoke...?

As I was driving down the freeway yesterday I began to smell the wonderful smell of gear oil, I thought it might be my mechanix gloves on the floor and think nothing of it. Then as I look in my mirrors i saw a faint cloud of bluish/black smoke coming from the rear side of the rig. Nothing felt wrong, the gages looked fine, no weird sounds...nothing. I figured id take a look when i got home. This is what i found:

http://picasaweb.google.com/Cannon.Clark/Jeep/photo#5165488363073311394

if you are unable to tell from the photos, there is gear oil covering just about everything from the entire driveshaft, to the exhaust (where the smoke was coming from), to the rear diff. I dont see any cracks or leaks in the transfercase, but i know thats where it has to be coming from...i just dont know why, or how...

My current setup is a makeshift short arm 6" suspension, with no sye, and 33"s. I have a HP D30 up front and a 8.25 in the rear. Like i said, i didnt hear any sounds of anything breaking or anything like that, and from what i can tell it was driving fine. I havent driven it since i parked it in the driveway yesterday...If anyone can see anything unusuall from the pics, or have maybe had this same problem and can lead me to a starting point on things to check for that would be great. Thanks alot!

Check all tranny lines, vent hoses (TC too) and seals...

Check your vent line on the front diff. If you get the least amount of water in there with the line off, when the diff heats up on the road, it will spew oil everywhere.

ok my first question is are you sure it's gear oil? gear oil doesnt belong in the t/case... that should be trany fluid in there. if its on the driveshaft and the floor around it, it seems like its coming from your rear output seal.. since you say it started on the highway you may have overheated the trany and boiled it out the dipstick tube.. were you towing?

hmmm...im SURE its gear oil, and yes, its EVERYWHERE...from the Tcase back to the gastank. i know where the vent lines are for the diffs, but which others should i check and where are they?

thanks for the help so far!

ooh and i wasnt towing anything

well if you have gear oil in your transfer case you have issues anyways.

transmission fluid belongs in the t-case NOT gear oil.

haha yea i should probably double check and make sure...the more i think about it the more im wondering what i filled it with a couple months ago...
i doubt i could have done something that stupid without noticing it before now...but then again who knows

ok so i think weve narrowed it down to one of the diffs. but what vent line would cause it to explode from the Tcase back to the rear diff...would it be the front diff or rear? im not sure i have a vent line on the rear diff...
hmm more help would be great...thanks!!

UPDATE:
it does seem very possible to have been the rear diff that spewed the black goo. although...i dont have a vent hose on it, and where the hose is supposed to attach, it doesnt look like the oil came from there...is there anywhere else it could have come out?! ex. the pinion seal?

please help!!

My t-case leaks from the rear output and made a pretty good mess, I can imagine that a really badly leaking one would coat even more of the underside of the jeep. Look for a drop or two of fluid hanging off the rear output shaft of the t-case.

Oh, and the PO had gear oil in my 242 when I bought it (changed it out of course!). Going to change it again when I do the seal, gotta get around to it sooner than later.

TXSizedJeep said:

UPDATE:
it does seem very possible to have been the rear diff that spewed the black goo. although...i dont have a vent hose on it, and where the hose is supposed to attach, it doesnt look like the oil came from there...is there anywhere else it could have come out?! ex. the pinion seal?

please help!!

Click to expand...

vent hose for the rear is on the brakeline mount on the driverside axle tube... it runs to a lil nipple on the framerail.

thanks alot guys, it WAS the rear diff...there isnt a vent hose on it at all right now...i guess i should probably get one

what else can i do to keep this from happening again?

use hose clamps and make sure you get one long enough that your jeep can flex and still have some slack