DIY: Rear Differential Breather Mod

Just to kill the mis information rampant on this thread once and for all, here are pictures of the diff vent. A pic with the spring pressure and me pushing down on it.

 

Can you dissect it so we can see the inner workings?

 

I have seen water damage created by these valves only on the rear end that ended up in expensive repairs. I could analyze the shit of of this or simply relocate it to a safer location and save all that thought for something more worthwhile. I choose the later

 

I did the mod today and found the factory breather seized shut with corrosion.

 

So use a hose and same factory breather?

 

You can, but I think most pick up a front breather as it has a barbed end instead of threaded.
Part number

$6 90930-03136 Toyota Breather Plug - 90930-03136

90930-03136 is what I used.

 

Ha! I did this mod in my old Titan, but for a different reason. The titans love to blow rear axle seals.
First post for me, picking up my 2013 CM today!

 

I ended up running an extension behind the taillight and an open ended filter. Then I got worried about condensation and another potential issue I can’t recall at the moment, so I added the oem breather to the assembly behind the taillight.

 

With breather filter

 

Just routed the breather to behind my taillight and noticed that my camper shell fills up with the smell of gear oil. No bueno. Gonna try to run it into my gas door.

 

Also, for anyone doing this, the little hole at the arrow - - - is threaded. perfect place for a hose clamp.

 

Thanks guys Ordered my stuff today. I'll get it setup and do some creeking next weekend.

 

Is it possible to do without touching spare at all?

 

The re-route won't interfere with the spare tire at all, and you don't need to remove the spare to get the job done.

 

Thanks

 

So Im going to do the rear diff breather mod and went ahead and ordered part number

$6 90930-03136 Toyota Breather Plug - 90930-03136

90930-03136 (breather) and

$8 90404-51319 Toyota Union - 90404-51319

90404-51319 (axel fitting) from my local dealer. After placing the order it got me thinking.


Why are guys using part number 90930-03136 instead of just using the same part number that your truck uses for the front diff breather?


I got a 2020 and I believe the front diff breather part number is 90930-03208.


Would it not be a good idea to use the more up to date part number. Maybe Toyota improved it over the years.


Has anyone done this?

 

You don't need the breather 91930-03136 or 90930-03208 because you already have one (or the other). It's currently attached to your truck. Just the hose, the nipple

$8 90404-51319 Toyota Union - 90404-51319

90404-51319, and some clamps and ties as you like them.

It's a mechanically simple part, so I'm not sure any improvements could have been made; and in the long and short of it, anything that would keep dust out would work just fine.

 

Ok.?? Living in the midwest we get lots of salt on are streets an roads.Is there a zip tie brand that will hold up to salt? Or am I over thinking it??

 

Stainless clamp, and any ziptie should be fine. Plastic doesnt rust

 

ya just check at a store they have some good for -40 degrees

 

Ok I had a little extra time on my hands and went ahead and ordered part # 90930-03208 (front diff breather 2020 Tundra). Below is a side-by-side comparison of the two parts.


You can see that the hose end for 90930-03208 is narrower then

$6 90930-03136 Toyota Breather Plug - 90930-03136

90930-03136. This would cause a hose fitment issue if using

$8 90404-51319 Toyota Union - 90404-51319

90404-51319 (union).


If the male hose end diameter was wider on 90930-03208 I would have preferred to use this part because it would allow for better airflow then 90930-03136.


So to sum it up stick with the original part numbers mentioned at the start of thread and save yourself the time.

 

Hey guys, I did the rear diff breather a while back and went to check up on it and saw that the fuel filter I used had some condensation in it. I don’t think that any water went inside of the rear diff (at least I’m hoping not) I’m headed to the parts store to get a different filter. Just curious if anyone else has ran into this issue. Maybe it was the filter that I used since it has an additional nipple on the top.

 

I haven't done the mod yet but I've got everything to do it, with a filter just like you have.
Do you have the filter behind your brake light?

 

Yes, I swapped it out with a different filter should be fine

 

@NWPirate Here is the filter that I used and how I stowed it.

 

Nice work, looks good.
How much slack do you have coming off of the diff for travel?

 

A pretty good amount. Nothing where it’s hanging loose but it’s enough for flex

 

I see that some are using the OEM breather which will close when the differential gets cold such as a water crossing and others are using a filter which remains open.

My understanding is that the OEM breather route does not solve the issue, since when the breather closes due to cold water on the differential, a vacuum could form and water can be drawn in through the axle seals. This is why some use the filter. The ARB breather relocation follows this methodology by using a open filtered breather block.

Is there a reason that some are not using the filter method but are instead opting to stick with the OEM breather, just relocated?

 

I got the dorman 2 way breather, it passed the suck test, barely. I cut 3 V shaped groves on the lip of the plastic under the cap and now passes the suck test perfectly.

 

Do you have a link?