Rear Diff Breather Mod - Complete!

[Saker]

Ok so I am guessing that this scuba part is a multi use twoway valve? Is there a real benefit to that one over just buying the 2 way from toyota already listed in the thread?

It is not a 2 way valve. It is a manifold with a filter that will allow pressure to equalize within the differential. It has multiple ports for installing more than one hose. Since I only needed one hose, I placed a 1/8" NPT plug into the other one.
I guess it is personal preference, but the one I use has a filter and it looks a lot better! ::rofl:
Obviously the other one listed works too......

 

[mfregeau20]

It is not a 2 way valve. It is a manifold with a filter that will allow pressure to equalize within the differential. It has multiple ports for installing more than one hose. Since I only needed one hose, I placed a 1/8" NPT plug into the other one.
I guess it is personal preference, but the one I use has a filter and it looks a lot better! ::rofl:
Obviously the other one listed works too......

Cool, it does look better :wow:

For the sake of conversation and others this would be good to get if you are installing a rear locker like an ARB one. I have read on here that you need a filter for that application.

 

[Canazes9]

This is for all you guys with a TE right? The TE is the only model with a rear differential.

Am I safe to assume the SR5/Limited would not need this mod? (I believe the LE only has a center diff, not sure about the SR5)

All 4runners have a rear differential, the TE has the e-locker rear diff. This mod is a good idea for any 4-runner that might see moderately high water.

David

 

[Canazes9]

Cool, it does look better :wow:

For the sake of conversation and others this would be good to get if you are installing a rear locker like an ARB one. I have read on here that you need a filter for that application.

You do not a filter for the ARB locker - the amount of air flow is minuscule. If it makes you feel better use the filter, it will make no difference to your differential.

David

 

[mfregeau20]

You do not a filter for the ARB locker - the amount of air flow is minuscule. If it makes you feel better use the filter, it will make no difference to your differential.

David

Thanks for the clearification

 

[sandcrawler]

that manifold with the polyethylene filter is pretty trick for the jack compartment. to date, i don't think i've ever seen anyone use the ARB 4-port manifold. i think it uses a sintered filter: ARB Differential Breather Kit (170112)

there's also this kit from Air-on-Board: 4 Port Diff Breather -Air On Board

this is on my to-do list.

 

[Cincyvol]

Dumb question...I've read through a number of the rear diff mod threads and some seem to reference 1/4" fuel line, some say 5/16 and others say 3/8. All seem to reference the same part numbers, though for the connection piece. What size should be used for this?

 

[Saker]

Dumb question...I've read through a number of the rear diff mod threads and some seem to reference 1/4" fuel line, some say 5/16 and others say 3/8. All seem to reference the same part numbers, though for the connection piece. What size should be used for this?

This part for 1/4" Fuel Line
(1) 90404-51026 Toyota 1/4" Fuel Line Union

 

[Saker]

This post is for those out there that are skeptical of placing the breather or vent in the rear cab because of possible smell of the Diff Fluid.
Since I installed mine, I have not smelled it one time, even after opening the compartment to check!

I have checked after driving for several hours, no smell.

I just made a trip where I drove 900 miles with only about 1.5 hours of stoppage, no smell at all.

Just giving everyone a heads-up.

 

[1traildriver]

So I bought a kit to do the rear diff breather, which has a manifold for 4 extended breathers. So after reading this thread I do not have to do the front diff, trans and transfer case??? It was mentioned that those three components already have an extended breather that leads to the fire wall? how high and where?
Thanks!

 

[st8rocks]

So I bought a kit to do the rear diff breather, which has a manifold for 4 extended breathers. So after reading this thread I do not have to do the front diff, trans and transfer case??? It was mentioned that those three components already have an extended breather that leads to the fire wall? how high and where?
Thanks!

You could route them all together. I believe the factory front breathers are on the firewall in the engine bay.

 

[Jeremy556]

So I bought a kit to do the rear diff breather, which has a manifold for 4 extended breathers. So after reading this thread I do not have to do the front diff, trans and transfer case??? It was mentioned that those three components already have an extended breather that leads to the fire wall? how high and where?
Thanks!

On the driver's side wheel well, near the fuse box. If you are adding air lockers, you should change out the 1 way toyota valves for a filter, to avoid gear oil in your air lines.

 

[1traildriver]

Thanks!

 

[Boyds4Runner]

Total Number of Breathers on 2015 TRD Pro (Trail too most likely) 7!

First of all great thread that no matter how old, still applies.

Having just relocated the rear-diff and e-Locker breather to the engine bay I poked around while under the car to trace and count the total number of breathers.

On the 2015 TRD Pro (as others have already mentioned throughout the Forum it is basically a Trail Edition with TRD Pro extras) I counted a total of 7 breathers! 5 of them routed up high enough to the height of the tires in the engine bay or slightly above and the two rear ones...not so high.

1 - Rear differential
1 - Rear differential e-Locker (if equipped) small extension to a cross bar slightly above the axle toward the spare tire on driver side.
2 - coming from out of the part-time 4 wheel drive transfer case
1 - coming from transmission
The transfer case and transmission total of three breathers are extended up to the firewall pretty much following center line from ontop of transmission housing up to behind the center of the engine at about the height of the tires. Really hard to see from hood side unless one is laying inside the engine bay looking down between the firewall and engine. There is a larger plastic breather (I believe the transmission one) and two smaller, metal, thimble type breathers (I followed those two to the Transfer case).
1 - Front Differential
1 - Front Differential actuator ?
The front axle, two breathers are extended to the driver side wheel-well just underneath where the fuse box assembly bolts to the top side of the wheel-well/fender.

My 2004 SR5 for comparison had the center-diff lock type transfer case. I only saw the rear axle breather, one for the transmission and two in the engine bay on the driver side wheel-well for a total of 4. I am sure I missed the ones that must have existed for the center diff somewhere.

Pictures of the 2015 transfer case and transmission breathers are hard to get but below is a try with the three centered in the picture. Hopefully the descriptions above help for users trying the well documented mod here in case anyone wants to put all breathers into a manifold type, zero-pressure style breather.

 

[96r50]

Here are the diagrams of all the breathers on the truck other than the rear axle as described by [MENTION=3442]Boyds4Runner[/MENTION]

The breathers are all the same regardless of trim level.

Part numbers for the breather heads:
90930-03188 Transmission
90930-03172 Transfer (x2)
90930-03159 Rear Locker Actuator
90930-03136 Front Differential (#1)
90930-03159 Front Differential (#2)

 

[bimrunner]

edit: N/M carry on.

 

[viking-777]

I had a differential fail in my last 4x4 and had to get it replaced. It wasn't cheap :ybrick: Dealer said they had no idea why it failed. I thought it must have had something to do with driving in the OBX deep sand, but from this thread, I suppose it could have been all those water crossings I did getting to remote kite boarding, fishing, or clamming spots. I don't really know the diff breather setup of the VW Touareg, but I do know I will take my TRD Pro to the same spots, and will plan to add this diff breather mod for sure. Thanks for all your input. :fishing:

 

[viking-777]

First of all great thread that no matter how old, still applies.

Having just relocated the rear-diff and e-Locker breather to the engine bay I poked around while under the car to trace and count the total number of breathers.

On the 2015 TRD Pro (as others have already mentioned throughout the Forum it is basically a Trail Edition with TRD Pro extras) I counted a total of 7 breathers! 5 of them routed up high enough to the height of the tires in the engine bay or slightly above and the two rear ones...not so high.

1 - Rear differential
1 - Rear differential e-Locker (if equipped) small extension to a cross bar slightly above the axle toward the spare tire on driver side.
2 - coming from out of the part-time 4 wheel drive transfer case
1 - coming from transmission
The transfer case and transmission total of three breathers are extended up to the firewall pretty much following center line from ontop of transmission housing up to behind the center of the engine at about the height of the tires. Really hard to see from hood side unless one is laying inside the engine bay looking down between the firewall and engine. There is a larger plastic breather (I believe the transmission one) and two smaller, metal, thimble type breathers (I followed those two to the Transfer case).
1 - Front Differential
1 - Front Differential actuator ?
The front axle, two breathers are extended to the driver side wheel-well just underneath where the fuse box assembly bolts to the top side of the wheel-well/fender.

My 2004 SR5 for comparison had the center-diff lock type transfer case. I only saw the rear axle breather, one for the transmission and two in the engine bay on the driver side wheel-well for a total of 4. I am sure I missed the ones that must have existed for the center diff somewhere.

Pictures of the 2015 transfer case and transmission breathers are hard to get and be able to make sense of them but hopefully the descriptions above help for users trying the well documented mod here in case anyone wants to put all breathers into a manifold type, zero-pressure style breather.

Boyds4Runner: Excellent information. So for "Extended rear-axle and eLocker breather to ARB under hood", did you use the ARB-Differential-Breather-Kit-170112, and were the unions threaded correctly for the TRD Pro rear diff and eLocker? Thanks.

 

[mikey's2010SR5]

I really need to get this done soon.

 

[Boyds4Runner]

Boyds4Runner: Excellent information. So for "Extended rear-axle and eLocker breather to ARB under hood", did you use the ARB-Differential-Breather-Kit-170112, and were the unions threaded correctly for the TRD Pro rear diff and eLocker? Thanks.

Hey Viking-777 sorry for the late response! I often check this forum but don't always log in.

Yes that was the correct kit for the ARB and also, yes the union was threaded correctly for the TRD Pro Rear Diff. The eLocker doesn't need a union. The factory included a little rubber tube that has it's own plastic union piece a short distance off of the eLocker on the rear axle. I pulled the tubes apart at that plastic union leaving the longer tube going to the factory breather taped shut. The remaining stub coming from the e-Locker I inserted into the larger diameter fuel-line tube. I used a hose clamp, not too tight to keep the tubes from sliding apart. In the picture you can see the blackish, plastic union piece for the eLocker breather just to the right of where the bright light is shining: