Can a clogged breather cause the front diff to leak.

Hi Guys,

I did my ECGS bushing and OEM seal last year. I have about 25k on the set up. No issues.

I typically don't drive far other than my 30 minute commute. This past weekend I had a 3 hour round trip drive.

I haven't looked under the truck in a while, but I decided to look. I saw a little weep on the diff but it was a very miniscule amount. It was right where the axle meets the diff on the driver side. Axle has the usual play but nothing excessive. I brake cleaned the area and took a test drive and it stayed dry. The next day, I did the trip and when I got back I noticed the diff was wet. It wasn't dripping but deff had leaked a bit while driving. I was scratching my head as the diff would only leak while driving. I topped the diff off with the recommend lucas 85/140. Maybe took about 1/8 a Qt to top off so It didn't loose much fluid.

I poked around for a while, and I decided to check the breather that is in the engine bay on the driver side. There are 2 small breathers with metal top caps. The one for the 4wd actuator was fine but the one for the front diff was frozen. The top metal cap was frozen to the plastic part. It was so stuck I had to pry it off with a screw driver. I ended up ordering a new one and took the breather cap off. I took the truck for a 100 mile drive yesterday and ran it hard on the highway. 80+ MPH most the time. As of today the diff is dry.

I have read that a clogged breather can cause this but haven't seen it apply to anyone with a tacoma. Thoughts? I ordered a new seal and ECGS bushing just in case.

 

Absolutely it can, as temps go up so does pressure.
The vent is there to relieve that pressure, if the pressure can't get out the vent it will go out the next easiest place which is typically a seal.

 

Yes.
An easy fix/prevention - replacing/checking breathers - goes a long way. May as well check all of them. Some guys put teflon tape around the threads before installing.

 

The one for the front diff has a rubber tube that you can see in the engine bay. The valve looks like this. New one should be here today.

$6 Dorman 924-284 Front Differential Vent Breather Compatible with Select Lexus / Toyota Models

Amazon.com: Dorman 924-284 Front Differential Vent Breather Compatible with Select Lexus / Toyota Models : Automotive

 

Anyone know where the trans breather is? I can't find much by searching.

 

Lucky that the breather hose didnt pop off the barb. The intermediate hard line is where mine came loose.

 

I believe the one next to the diff breather up front is the combined transmission and transfer case vent if you have an automatic, if you have a manual the vent is up on top next to the shifter.
@TnShooter I believe can confirm.

 

The one furthest back is the one for the front diff. Surprise, it can like from there too. lol

 

As for the Transmission, I don’t know.
Hell, I don’t know if I want to know.
These breathers have caused me enough trouble. Mostly my fault for lack of maintenance and checking them. But once they get clogged, you get leaks.

 

Thats the one that was stuck shut. I had to pry on it with a pair of pliers.

Any idea where the breather is for the auto trans? I just want to check it. Last few weeks I have been getting an odd burning smell after the truck runs for a bit. Doesn't smell like your typical oil, coolant smell.

 

I was so pissed at first like efff this ECGS bushing. Its only been 25k Miles! Then I found the stuck breather lol.

Just checked again today and everything looks dry. Almost positive the breather was the issue.

 

Mine was open, it actually leaked from the breather. But there’s a reason.

See more here
https://www.tacomaworld.com/threads/front-diff-leaking-gear-oil-from-the-breather.744067/

 

I took the top breather off all together. The new one should be here today from Amazon. I looked down the tube with a flashlight and I don't see any trace of oil.

 

You shouldn’t unless you over filled the diff or used 85w-140 (Like I did)

 

I've had 85/140 in there since I did the bushing 25k ago. Never had an issue with it puking. I did make sure I topped it off properly. Truck on level ground an added fluid until its dripped out

 

Mine didn’t do it until it got cold outside.
Was fine for 7 months and 10k miles. Then it got cold out and leaked.

It’s not uncommon, the fix is to use

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 or let it puke out until it quotes. Then leave it alone.

 

Maybe I'm lucky but I ran this set up all winter with plenty of 0 degree days up here in the northeast.

 

The automatic trans breather is at the top of bell housing.

 

I think I found it?
What a task it is just to get a picture.

Follow this line up. It’s easier to see from passenger side

Driver side view


Passenger side view

 

If you want to puts hands on it.
Go under and reach up by the passenger cat. Or pull the splash guard off the passenger side.