Hello,

To my horror I have a leak, believe to be transmission oil, at the place where the transfer case and the engine meet. Attached is the pic. I notice when I squeeze area near the bolt, oil seep out. I try to turn the bolts and all seem very secured. There is an empty hole that I could place a fastener bolt through, should I do this to help fixing the leak ? This is my very first tacoma 4wd 5spd v6 , so please forgive my ignorance. What type of manual transmission oil should I used ? Thank you for help.

 

Probably a leaking rear main seal on the engine or input shaft seal on the transmission. However, in that location, it COULD be a leak at the rear of the valve cover(s) or even an oil leak at the head gasket (less likely, but still possible.)

You can get UV dye kits at most auto part stores. Dump the dye in the engine oil, drive it for a while and check the area with a UV light. If the leak is small/slow, it may take a few hundred miles of driving for the dye to migrate from the seal and to a place where the UV light can detect it.

If you want to be quick about it, put one color dye in the engine and another color dye in the transmission and see which color you get. Again, drive the truck for a while so the dyed oil has a chance to leak. That will narrow things down considerably and let you plan your repair.

 

obscurotron,

Thank you for very detail analysis. I check the engine oil dipstick and so far it has not gone down, so it is not engine oil. Plus, the oil feels cold even after the engine ran for a while. My guess is the input shaft seal on the transmission. I have not check the transmission oil yet but will soon.

If it is the input shaft seal on the transmission, does anyone know how difficult or expensive to fix it ?

 

The seal its self is easy to change.... Its getting the transmission out that is the hard part.

 

obscurotron is right. Rear main engine seal or trans input shaft seal.
If you're going to replace either, might as well replace the clutch while you're in there.
And actually, Looking at your picture again. If the oil is that high up on the bell housing, my vote is the rear main is out.

And BTW, the transfer case does not mate up with the engine. The transmission is mated to the engine.

And yes, if your engine is missing a bellhousing bolt, put the proper bolt in it's place

 

scuba,
The leak appears to be pretty high up on the bell housing and dripping down along the edge. I check the engine oil and the level stays the same. So my guess that it must be transmission oil. That would mean the rear main engine seal is going out. Thanks everyone for input. I will try to get some quotes for both clutch job and the seal replacement. The taco has about 110,000 miles and due for many major services such as timing belt water pump and breaks....

Can anyone suggest a good tacoma repair shops in or near Garden Grove, CA., specializing in 4wd rock crawler type services ?