Diagnosing ATF Leak in 2001 LC (166k) (1 Viewer)

[csmith1202]

Hi all,

I was removing a splash guard yesterday and made the pretty unfortunate discovery that I'm leaking some automatic transmission fluid. It was in a little pool at the bottom of the splash guard. I don't have too much of an idea on where the main leak is coming from because honestly it seems like it's coming from a few locations. Most likely location seems to be right from a bolt in the first picture which makes me think a seal went bad. We've been having pretty extreme weather in MT for the last few months so that could have something to do with it. Has anyone had a similar problem? If so, how did you go about fixing it?

Thanks.

 

[76lcmike]

any chance you overheated it and it blew out the dipstick???

 

[csmith1202]

any chance you overheated it and it blew out the dipstick???

that’s a probability. i had a second eye look at it and they said that they thought it could’ve heated up to a point the fluid expanded

 

[awesomeissquid]

What temperature would it need to be to expand and come out the dipstick?

 

[JunkCrzr89]

What temperature would it need to be to expand and come out the dipstick?

More likely overfilled or spilled while filling…

Most likely location seems to be right from a bolt in the first picture which makes me think a seal went bad

Not the bolt. The leak is higher up. Looks like it came out the top of the dipstick tube. Was the dipstick inserted all the way so that the o-ring at the top seals the tube? Or perhaps the ATF was topped off recently and there was spillage?

 

[2001LC]

The breather for the transmission & transfer-case, terminate over that area you're leaking from. Get you camera out an shoot a pic of it.. You did NOT state year. But I'll assume 98-02. Which has one breather for both transmission & transfer-case lines/hoses, with a Y adapter at top rear LH of trans, that both lines tie into. If over-filled or and or overheated and or contaminated fluids. One or both may have blown out the breather. If so you've likely cross contaminated into both. IIRC, in 2003 Toyota separated these breather hoses. As have many as they install new and higher point breather and hoses.

While on level ground:
Check Transmission level, while engine idling, in P or N after shifting through all gears. Make sure AT at ~165F (156 to 176F).
Check transfer-case level after driving the let sit 10 minutes.
While checking transfer case. Pull the breather hose that goes from back to front of transmission (long hose) off the Y connection. Just let hose hang down to the ground, into a catch cup., to see if any drainage. Blow into rear end of hose going to breather with low pressure. I use my compressed air, regulated down to~5 to 10 PSI, to insure air flows through and out breather.

BTW: I use Mobil 1 gear lube 75W-90.
ATF, I do a full 12 qt flush, with Mobil 1 MV ATF in 98-02.

Will transfer-case gear lube foam, if contaminated or overfill?

Edited 11/19/22. This thread gets more into foaming of lubricates, causes and effects. The two main causes of excessive foaming, we're concerned with: Overfilling and contamination. I also came to conclusion, with helpful post from others and looking at adapter case. It would be nearly...

forum.ih8mud.com

Make sure coolant system work as it should, and no blockage in any of the 3 radiator's fins.

Radiator fins need cleaning! Alert Alert Alert

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added...

forum.ih8mud.com

 

[csmith1202]

The breather for the transmission & transfer-case, terminate over that area you're leaking from. Get you camera out an shoot a pic of it.. You did NOT state year. But I'll assume 98-02. Which has one breather for both transmission & transfer-case lines/hoses, with a Y adapter at top rear LH of trans, that both lines tie into. If over-filled or and or overheated and or contaminated fluids. One or both may have blown out the breather. If so you've likely cross contaminated into both. IIRC, in 2003 Toyota separated these breather hoses. As have many as they install new and higher point breather and hoses.

While on level ground:
Check Transmission level, while engine idling, in P or N after shifting through all gears. Make sure AT at ~165F (156 to 176F).
Check transfer-case level after driving the let sit 10 minutes.
While checking transfer case. Pull the breather hose that goes from back to front of transmission (long hose) off the Y connection. Just let hose hang down to the ground, into a catch cup., to see if any drainage. Blow into rear end of hose going to breather with low pressure. I use my compressed air, regulated down to~5 to 10 PSI, to insure air flows through and out breather.

BTW: I use Mobil 1 gear lube 75W-90.
ATF, I do a full 12 qt flush, with Mobil 1 MV ATF in 98-02.

Will transfer-case gear lube foam, if contaminated or overfill?

Edited 11/19/22. This thread gets more into foaming of lubricates, causes and effects. The two main causes of excessive foaming, we're concerned with: Overfilling and contamination. I also came to conclusion, with helpful post from others and looking at adapter case. It would be nearly...

forum.ih8mud.com

Make sure coolant system work as it should, and no blockage in any of the 3 radiator's fins.

Radiator fins need cleaning! Alert Alert Alert

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added...

forum.ih8mud.com

Thanks for the help. Yeah that's my bad forgetting to state year, I have a 2001. In recent memory I haven't topped up trans fluid nor has anyone else. Right now I'm likely assuming it was an overheating problem. When I'm back in the shop I'll be sure to run through those troubleshooting steps and report back here. Thanks again.

 

[76lcmike]

What temperature would it need to be to expand and come out the dipstick?

Oh if I had to guess, 300 degrees or higher