I need some help...

I have a trans fluid leak. It was a SUDDEN leak, not a slow leak. I suspect the trans is almost dry at this point and it will not shift into gear. I changed the oil/oil filter, did some front end work to re-align the headlights, and put everything back together. I was thinking I clipped something like a hose putting the skid plates back on but can't figure it out.

It's not the drip pan as far as I can tell... the gaskets look OK, but the bolts did have drips coming from them. The bolts were not that tight either... maybe the problem?

It's not the trans overflow tube as per this post: https://www.hummerforums.com/forum/h...lp-leak-37065/

The leak itself appears to be coming from the front end somewhere. The trans pan is not covered by the mid skid plate, but both skid plates were coated on the inside with trans fluid. I suspected maybe it was the trans dip stick, but I checked it all the way down to the base and no fresh fluid buildup.

The only area I can find that may be the issue is the front diff... but I didn't think that fluid would be in the front diff? I also didn't think if the front diff went out, that I would lose my gears totally...

Please help!

 

Oh and it's a 09 H3 I-5, if that helps.

 

Did you check the trans fluid level? Pull the dipstick and let us know.

Your trans fluid runs through the two lines that connect to the rear bottom of the radiator. Those lines are metal at each end with rubber flex hose crimped onto the metal ends. Those crimps have been known to fail (My last GMC blew its remote oil filter lines with the same crimp type hoses twice). If the crimp comes loose enough, trans fluid will pump/leak out and as you are driving the fluid blows back along the bottom of the motor and trans etc. Drop the front skid plate and give those two trans hoses a close look.

 

Thanks. I put a gallon of Dexron VI in it and it's still low but registering on the stick. I got my gears back too. I dried those ends off near the rubber crimps and where it connects to the radiator as much as possible then drove it about a 1/4 mile and pulled up on some cardboard to check for drips... the hoses are not leaking now, odd.

I did notice drips coming off the back of the front diff, at least I think I traced them to that. I thought it might have been the trans fluid stick tube, but it's not. Old fluid is still cooking on the pipes/catalytic converter some, so I got some smoke coming off that side of the engine, but I don't see anything else.

Would certain types of Dexron VI seal any leaks? I lost almost all my fluid in a 4 mile stretch so it had to be a serious leak before, now I got nothing.

 

Check your Radiator fluid, is the color and level correct in the overflow tank? If you have an internal radiator leak that lets trans fluid mix with coolant, that can be difficult to find the leak.

You might be blowing fluid out the Trans vent because of the trans getting too hot?

 

Any resolution to this drip problem?

 

This same thing just happened to me today! I was driving and for about an hour then got to my destination to see I was excessively leaking trans fluid. I washed the undercarriage then refilled the trans fluid to find the leak...but nothing! I even tried to replicate the problem by driving an hour on the interstate to test after not finding any leaks and nothing again.... it's like my transmission leaked all its fluid then stopped leaking on its it own.. confusing

 

antifreeze and oil do not mix. the antifreeze displaces the transmission fluid causing it to blow out of the transmission breather since the oil floats on top. check your coolant levels. check you do not have coolant in the transmission. if you do you need to replace the radiator. and hopefully not the transmission as well.