Clogged Front Diff Breather

Hey I have 2004 V6 3.4L 4WD TRD Off-Road. Looks like the front diff breather spewed some oil out of it and it's now clogged up. I was going to replace it but wanted to make sure I replace the right part.

I know it's one of the two (or both) valves in the photos below





My question is are those both breathers for the front diff if not what are they breathers for? They both need replaced. The one of the left spewed oil and is sealed shut. The one on the right has some play but not much (due to the residual oil from the one one on the left splashing onto it).

Thanks all!

 

Pretty sure the other one is for the front ADD actuator breather

 

Probably my inexperience here but what does ADD stand for? Not sure if it matters - found a parts diagram looks like they are same part (41110R):

 

Automatic Disconnecting Differential.

 

When mine got clogged, all I had to do was free up the cap on there and it worked fine after that.

 

I'm having the same problem as you. Thought I'd let you know that those two breather plugs are not the same part. If you pull them off, you'll see that the nipples are a different size in order to fit in the different diameter hoses. You want part

$7 90930-03136 Toyota Breather Plug - 90930-03136

90930-03136 for the larger hose, which goes to the actual front differential.

I'm trying to find out the part number for the smaller one, so that I can replace both. My saga is here:

https://www.tacomaworld.com/threads/another-leaking-front-differential-breather.851162/

 

Why was it spewing oil? I e never had a diff breather spew oil

 

Cross-posting a very helpful pic from another post entered earlier today. I have added it to my "obscure parts list" I have been adding to over the years. Trying to confirm these are the correct parts for a 1st or 2nd Gen Tacoma or both.

 

Man, both of those parts sure do look exactly like what I have on my truck, but they both show up as incompatible on all of the parts sites. For my model, the websites refer me back to part number

$7 90930-03136 Toyota Breather Plug - 90930-03136

90930-03136 for the larger diameter one, but I'm still coming up empty handed for the smaller one.

 

I never had one spew gear oil either, until it did . When I started researching the problem, I discovered it is actually a frequent occurrence on these 1Gen's. Various explanations have been given, but none of them make sense or apply to my circumstances. More detail here: https://www.tacomaworld.com/threads/another-leaking-front-differential-breather.851162/

 

Thank you all for the replies. I stopped by the parts department at my local dealer and the larger diameter piece can be bought as it's own part. If it works I'll give you all the part number. The smaller diameter piece needs to be bought with the hose (it's still not expensive) I'll post it if it works. I potentially found the smaller diameter part at Autozone too (without the hose) if that works I'll give the part number so if anyone wants it they don't have to buy the hose too.

I will say I managed to free up the breathers with some pliers. I'm not sure how much play they should have to be working properly. The larger diameter valve spins pretty freely. The smaller valve spins but with a lot of pressure from my fingers. Neither of them can be pulled up and down easily (but this might be intended? Since the valves should only open when air pressure is applied to them from the hoses?)

 

Do you mind sharing the part numbers now? They might not fix the issue for you, but they might for me ;-)

 

This is the best explanation I found:

https://www.tacomaworld.com/threads...atched. No puking for 17 years.,-Last edited:

Basically at high elevations and cold weather (such as winter in the Colorado Rockies where I live) the front diff fluid can rise up the breather hoses and spew out the breather valve.

Basically increases in elevation and decreases in temperature cause air pressure on the outside of the breather valves to drop so low the air pressure caused by the hot differential fluid can also force the differential fluid out with it. Contrast this situation driving at sea-level in room temperature air. There is enough pressure on the outside of the bleeder valves to "push" the heavier differential fluid downwards and out of the hoses but the hot air created by differential is still light enough to come out of the breathers. There might be some holes in this logic but it helps me make sense of the situation.

 

Dealer had to order the parts the won't be here until next week. I won't have an invoice with part number and the parts until then. I might get the autozone part tonight if not I'll have it Sunday I'll post it when I get it.

 

Did you happen to figure out if these are the correct parts for a first gen?

 

This is an interesting (good) post. It's starting to look like maybe these two parts should be treated as/like a scheduled maintenance item item, and checked on a regular basis, especially since some can start throwing diff fluid without any warning. I have the two vents like this on my 2nd gen. I went out an checked them and they are moving free, but they do appear to be original and have 134,000 miles on them and almost 12 years.

 

There is also a rear diff vent - mine is rusted over completely and seized up. It's probably been like that for years now (this saga made me look into the rear diff too). I got no leaks from the rear diff but def going to replace that bad boy too. Probably check on them every oil change to make sure all is well with them. The fact that the rear diff is seized and I got no leaks makes me wonder how big of an issue this is but still going to add it to maintenence.

 

The rear breather helps preventing water getting into axle housing when driving through deep waters. So no leaks is good, but still, cheap fix to avoid any risks.

 

And to let the hot air from diff running escape yeah? If it's rusted shut the air has to go somewhere - probably out of a seal of some kind. Here's a good video for the replacement. It's easy and the part is cheap - https://www.youtube.com/watch?v=tQMUEuS3ZP0

 

It will be a big deal if any increased pressure due to normal heating escapes via the various seals instead of the clogged up or inoperative vent. Likewise any condensation that forms with normal heating and has nowhere vent as the fluid heats up.