leaking atf
 

Hi all, I have a 2005 GMC Jimmy 4.3L, auto, 3 button 4x4. The last year in Canada before gm discontinued it. I notice my transmission fluid under my jimmy. I thought it only leaked after ive parked after driving to and from work. I placed a cardboard under the Jimmy and I haven't driven it for 3 days. Today I noticed a few drips of ATF on the carboard, not a lot, but its concerning.

Ive read the output seal can cause this, but are there any other seals/gaskets it can leak from when the car is off?

I think the best thing to do is take a flashlight and inspect where the leak is coming from first and foremost. Front of tranny, back of tranny, side of tranny where the cooler lines are? Perhaps somewhere around the transfer case?

It will also help if you can get it clean under the hood and the underside of the transmission area. I discovered mine was leaking at the cooler line where it connects to the radiator. Quite messy, as the wind blows it all over the undercarriage as I drive.

Thank you I'll have to check it during the weekend at my buddy's heated garage. -30C is not fun. I did notice the tranny pan is saturated. But would it leak from the gasket when the car is off?

thank you, would engine degreaser or brake cleaner work?

Yes it will leak with the car off. I think the degreaser followed by a spray car wash will do a better job and won't melt your plastic pieces.

At -30°C, I wouldn't be worrying about a few drips of trans fluid. This isn't the time of year to worry about non-critical leaks. I'm guessing you can keep the trans fluid level topped off and save the repair for Summer.

I would agree with LesMyer on the urgency to get repaired. If it seems to be dripping from the front area of the passenger side I would also suspect a failed seal at the input shaft of transfer case. This is very common and not terribly hard repair. What happens is the seal will let transmission fluid enter the transfer case thus over filling the transfer case and it will spit it out through the breather hose that just happens to be up at the top of dipstick area and leak and follow the tube down. Keep a check in fluid level and monitor the amount that is lost on the cardboard. Also transmission fluid will spread out tremendously from a small amount and make you believe it was a crime seen LOL!
Good luck
Brad

Yeah I'm not too worried tbh. I have 2 5L jugs in the back so I'm not too concerned. It's weird, I always check my parking spot at work, and it is always dry. It just leaks when I get home, but not every night! Cardboard has drips every other night. Anyways, a coworker told me about blue devil transmission seal. I'm a bit skeptical to use any stop leak product, but maybe it can slow it down.

Thank you for the detailed explanation, maybe that is why I get drips on the cardboard every other night. Overflowing from the breather when full. I always check the dipstick every 3 days when I get to work. (While car is on, I cycle through the P, N, R, 3, 2, 1, wipe dipstick, stick it back, wait 5-10sec, and recheck stick)

It seems like its dripping just over the cat or resonator exhaust pipe. I will have to double check with a fresh card board tonight.

It's best not to use any type of quick fix sealers they turn seals to GOO so they reseal but GOO only lasts so long then it leaks worse .....