Ok. I own a 1991 C1500 with the 5.7 engine. Its the automatic transmission, although I am not sure which one it is. Its the stock transmission. The truck has 122,000 miles on it. I had the transmission fluid and filter changed about 2 years ago at 105,000 miles. Other than a slight shutter at 30-40mph when I hit the gas I have never had any ongoing drivetrain issues.

I had my truck bed fully loaded with my belongings Moving about 1200 miles. About 15 miles away from my final destination, I smell burning oil, and I look behind me to a cloud of white smoke. I pull over and raise the hood. White smoke everywhere. There is engine oil pooled up near the valve cover on the right side of the engine. Although I thought it was a little odd all that smoke came from what looked like leaked valve cover gasket oil, I ended up getting it towed, just in case. When I get to the house, I start it, and the engine turns over and runs great like always. I put it in reverse. Doesn't move. Forward. Doesn't move. I start looking under the truck. oil EVERYWHERE. check the transmission dipstick. looks pretty much empty and smells burnt. I have yet to find where the transmission oil came from to begin with. The engine oil on pooled on top by the valve covers is still a mystery. Any ideas?

I am pretty sure my transmission is shot, but I would like to hear other opinions or other things to check before I give up and go out and start looking for a transmission.

 

Sounds to me like you blew a transmission line. It hit the exhaust pipes causing all that smoke

Trans is empty........Is the engine oil level OK?

Have a good look at the trans cooling lines. If you cant see where its leaking, put a bit of tranny fluid in the trans and start it up for a second....Look underneath and you will likely see your leak. With any luck, no damage was done to the trans, since you were smart and had it towed
Good luck

 

Yeah, what ponscho62 said. Hopefully the trans isn't damaged, but most likely a transmission line blew out. Should be on the passenger side of the truck underneath the exhaust manifold running along side of the engine oil pan going up to the radiator.

 

I was just reading on another forum where he posted the question too...Turns out, the rear seal blew out of the tranny......different leak, same effect

 

The whole seal literally popped out? Trans vent is probably plugged up then ... At least that's all that happened to it. Strange how trans fluid ended up on the intake though, but if the vent is plugged it makes sense. Probably came out of the dipstick tube.

 

Yep, the whole seal popped out. I am starting to think it has been damaged a while. I replaced the transmission mount underneath that seal a year or so again. Transmission would have pushing the driveshaft down on that seal pretty hard before I replaced the seal. Just a thought. Where is the vent at? I would like to check that.

I replaced the seal and refilled the fluid (took 6 qts). I was able to drive it around the neighborhood but I have not given it a real test yet. It is making a noise that sounds like its from the front of the transmission that sounds like metal plates scraping together. The noise increases and decreases based on speed. Not too optimistic, but at least it moves now. Thats a start.

 

Normally when the trans is opened up and being worked on, you'd want to blow that out with a compressed air. Considering you have parts inside your trans still, you'd blow the blockage back into the transmission ... So at this point, I'd say f*ck it, she's noisy anyways, blow the sucker out and hope for the best. Maybe pull the pan and look for debris. Unless you blew up ALLOT of hard parts inside the trans, and it wouldn't move anywhere anyways, there's really no way for that seal to by physically "pushed" out unless the pressure buildup from the blocked vent is what did it. And the fluid you found on the intake, I'm assuming is black trans fluid. That's clutch material that's worn off of the clutch disks. That's really the only reason it turns black.

That being said, a bottle of Lucas transfix wont hurt a darn thing. Pour in $12 worth of "keep me rolling" in a bottle and hope for the best. It doesn't sound good for that trans. Lets just hope the noise you hear is a bad bearing or a clutch pack gone metal on metal.

But if you do end up needing a rebuild, I highly recommend you put in a new beast sunshell. Just sayin', there's almost no reason to NOT put one in. The part will be in your hands, and if hasn't failed yet, it will. Spend the extra cash and put in a stronger sunshell and you'll thank yourself later.

 

Well, damn, I want to try that stuff but my fluid level is now full. Not sure overfilling it with that stuff is the best idea. Ill update after I mess around with it this weekend.