M35a3 Transmission Problem!

[Lccountryboy89]

I have a 1994 M35A3 that has been running flawlessly and no problems at all. When I got it back in May I changed the trans filter and checked and topped off all the fluids. Today I drove it back from where I keep it and when I went to check the trans fluid level it started overflowing from the dipstick (like a LOT). I thought maybe it was overfull and loosened the filter and drained off even more fluid just to be safe. Started it up, ran it through the gears, put it in neutral and checked it again and same thing. Overflow from the dipstick. I have no idea what's causing this. Could it be the fluid filter is clogged and causing back pressure?? Really confused by this...

Thanks!
Roger

 

[Jeepsinker]

The vent line is clogged. Probably has a dirt dobber nest in it.
Edit: either that or you seriously overfilled it.

 

[Lccountryboy89]

Ok thanks! I figured some line somewhere was clogged. Where exactly is this vent line?

 

[Jeepsinker]

Should be on or very near the top of the housing. I don't know for sure on your specific model, but usually about the middle of the case on top. Seen this happen on many, many different makes and brands of automatic transmissions.

 

[Floridianson]

Do believe there should be three lines looped around the back of your cab. It is the larger of the three.

 

[Lccountryboy89]

I found the 3 trans vent lines and I can freely blow air into all of them EXCEPT the smallest of the three. Could this be the problem? And what is the easiest way to unclog these vents? And are they easily accessible from the bottom of the truck? I don't want to blow compressed air into the opening of the vent line and shoot whatever is blocking it into the trans...

 

[Jeepsinker]

Follow where it goes, remove it at the source, and blow it out from that end. It could have gotten pinched or kinked or swelled from fluid that didn't agree with it too, so you should try to trace the entire length of line and inspect it.