So i purchased a 1990 4runner 4x4 auto with v6 a few weeks ago and its been leaking fluid from the front end. I changed the oil and put some lucas oil stop leak in it to hopefully slow the leak down. Didnt help. Its been over a week since oil change, steady puddles everytime i park. My oil level has not went down at all though. Trans fluid is good on levels too.

Im thinking it is something in the dtiveline but not sure what. Drove home from work tonight (4 mile drive) and when i parked it i noticed a burning smell...

I included some pictures from underneath. Any help would be greatly appreciated!!!

 

Looks like your oil drain bolt From the picture it looks like a rubber o ring under it rather then the correct gasket . Might just be the picture though

If not that rear main seal leaking out the front of the bell housing .

Is it engine oil or Transmission fluid ?? They smell quite different

The smell may have been what ever fluid burning off the exhaust .

 

Did you come over and takes pictures of the under side of my rig? Ha!

Get in that puddle and give us some clues. Just like he said up there^^^ What does it look like? Smell like? Taste like? what color is it? Let it drip on a white paper towel. That will dial in a color.

 

Here is the fluid leak on paper.
Im thinking its gear oil not engine oil. Im leaking Alot and my engine oil level has nog gone down.

Im planning on flushing the trans this weekend. The fluid is fairly over filled and pretty brown. Still has a redish tint to it though. But getting hard shifts and holding up going into o/d

Truck shows 276k but odo isnt working so unsure on total miles

 

 

If it's gear oil it would have a yellowish tint and smell kind of rancid. Compare the smell to the towel and the oil on the dip stick. Trans will smell slightly burnt and be red, gear oil should smell rancid or like something dead and have a yellow tint when you rub it between your finger tips. Engine oil will look like what's on your dip stick.
Just by looking at it.....it looks like engine oil.

 

Amount leaking after 3 days of being parked

 

the entire bottom of that bell housing is coated with oil, it's going to be hard to troubleshoot the source.

take it into the car wash and blow the engine and tranny off with high-pressure wash.

 

You would be surprised. It doesn't take a lot of oil to make that size of puddle. I'm leaning toward engine oil leak. Let the engine cool over night and wash the block and heads with a degreaser and pressure washer if you have one. Don't spray the electrical. Run it and look for where it's coming from.

 

Ill degrease it and get all the oil off tonight. Appreciate the help everyone!!

 

If you don't have a pressure washer a local car was is a good solution.

 

try some dye from the local parts store, run it for a while after you clean it and check with a black lite. if you put the dye in the engine and your leak doesn't glow it's from your tranny (or power steering being blown back when you're moving).

 

I'm not sure about all of the plumbing for the auto transmissions in these but with yours overfull, brown and leaking around the bell housing, I would see if you can get a look at the transmission breather which is located on top of the transmission. You guys help me out. Is there a cooler associated with these transmissions that could be damaged and allowing coolant to enter the transmission oil? If the transmission was getting excess pressure into it then it would try and relieve it through the breather and pour discolored transmission oil all around where your leak is. Would also explain transmission shifting issues. Get confirmation on whether or not it even has a cooler before you start down that rabbit hole but it still wouldn't hurt to look at that breather. If you need me to, I'll go take you a picture of the breather on an auto trans I have out back.

Also check around the back of your valve covers. Way back there where you may need a mirror to see. Very common place for an oil leak and the passenger side will drip straight down along a brake line bracket and fall directly on the manifold making a burning smell. 1st hand experience here.

 

Just to add one more possibility, my 1992 5 speed 3vze has an oil cooler on the driver side of the block. I don't know if the AT versions have them or not. They leak eventually, and can drip down the bell housing like mine did. Not too hard to reseal with a kit.

 

That is an excellent suggestion. When I first got my old 4runner. I was evaluating whether or not it was worth putting any real effort in to. I went under to look it over real good and found the transmission just covered in old oil that had built up over a long time. I figured I would clean it all up really good and then find the leaks I needed to fix. For a year now it's been really clean and I wondered where all that oil came from. When I saw your post it made a light come on and I went outside and looked at mine. Pretty good oil leak on it but a slow one. With time it is going to make it down to the bell housing and start heading to the ground. It's pretty dang hard to see if you're not looking for it.

I guess I just thought I only had one oil leak left to fix. I guess I'm glad I saw it though. I'd rather know about than not.

 

If it wouldnt be too much trouble to snap a pic that would be awesome. I will definitely check those valve covers as well.

 

Look there on the bell housing by the number 3. That little tube there is what I call the breather. It doesn't look like the normal diff breathers. It's just a metal tube coming out of the transmission with a little hood on the end of it. Again, I'm not all that familiar with the auto transmissions but I'm pretty sure that's what that is.

 

I don`t think gear oil smells anything like something dead

Unless dead things smell different down Yonder!!

Now that we think the Auto Transmission is over filled good possibility that is what is being pushed out.

Also like most Toyota Automatic Transmissions the coolant and trans fluid both share space in the radiator

All it takes is a failed solder joint or a crack for the two fluids to co mingle

 

Ok maybe not that bad, but it is a very stinky oil. Especially when it gets to hot.

 

So cleaned of some of old oil down there, didnt get the sludge off though... Im thinking it is more than likely the bell housing. Im assuming the fix is to replace that seal. Might have to take it to a shop for that. Dont think i have yhe required tools...

Also i was looking for a writeup on trans fluid flush and fill and couldnt find anything. Any of you guys know where a good write up is by chance?