How to: extended diff breathers

[consalvochris]

After being a lurker for a few years and doing nothing to contribute much to the forum, here is me giving back to the community....

Parts required:
2 x Toyota diff breathers p/n 90930-03097
25 ft of 5/8 fuel line from your local auto parts store
8 x small hose clamps for 5/8 line
1 x metal or plastic T to connect the transfer case and front diff lines together - I had to buy a assorted pack from autozone to get the right one (Dorman p/n 47329)
2 x grommet (I used a PCV valve grommet from autozone that matched up (Dorman p/n 42060)


Tools required:
7/8 or 1 inch hole saw
Common screwdriver
Pliers for the stock clamps in old breather lines
Assorted zip ties
Spray paint to ensure the holes you drilled do not rust too bad

Step 1.

Find your front breather line located on top of your front differential, remove it and save the plastic c clamp holding it up so you can use it later. Now route your new line and avoid the suspension, then clamp it on the front diff. You can route the line to the firewall or to the power steering reservoir (imagination in use). Connect the plastic T to one end.

Step 2. ( I know, big steps huh? That's what she said)

Find your transfer case breather, time to get dirty. Get under your cruiser and find your transmission dip stick tube ( I know you 2002 and up cruisers do not have one and well, I don't know where yours is, just get under there and look). So somewhere on the tube, your transfer case breather and transmission breathers connect to it. The lowest tube is your transfer case and this is the one to remove and replace. It does not go into the dip stick, even though it looks like it, the top line does go into it and that is your transmission breather and it uses the transmission dip stick tube (no need to mess with this one). Follow that lower line back to the transfer case and remove the connection. Install new line and route back up to engine bay from here, zip ties are great. Be sure to avoid the exhaust, mmmkay? Connect it to the other side of the plastic T you used for the front diff.

Step 3.

You can use that OEM plastic C clamp that was holding your old front diff breather line up and stuff it in a empty screw hole along the side of the engine bay like I did. Obviously, if you have AHC you probably don't have a lot of empty screw holes, I'm sorry but you can use your imagination on where to mount the breather. Attach your brand new Toyota breather to the new 5/8 tubing and connect it to the last open spot on the T.

Step 4. (The rear)

Find your rear diff breather line on your rear axle. Ok great, you already know where it is and you should. Remove the lining on your driver side rear wheel well. It's only 2 screws and a plastic popper thing. Now open your fuel door and to the left of of the gas cap and take a deep breathe, because that's where you are about to drill. Drill where I did and you will be safe. DO NOT GO DEEP - DO NOT GO DEEP - FOR THE LOVE OF GOD DO NOT GO DEEP - ok? or mmmmkay? There is a wiring bundle for who knows what about an inch under there - so you will have a huge headache on your hands if you drill into a bunch of wires. Now, once you drill a nice little 7/8 to 1 inch hole there, you will see another panel you have you drill into from the bottom - that's why you removed the wheel well liner. Find a good spot and just drill it, don't you go deep in there now....mmmkay - same rule as earlier. You can put a little spray paint on these fresh holes to minimize rusting - I'm completely screwed because I live in Jersey. Then use the grommets to perfectly fill the holes and route your diff breather line into them. Stick a Toyota breather on the one end and the clamp will ensure it does not fall through the hole in the gas cap area (see pic). Then just route your line with zip ties following the fuel line and connect it to your rear axle, make sure to leave slack above the axle. This is so you don't rip in the line when your axle moves up and down.

DONE

 

[consalvochris]

Feel free to add on if you've extended yours, this can be a one stop shop for anyone looking to do this

 

[3D FJ]

I think drilling the hole in the body by the fuel cap is not necessary. I was able to get mine in that location without having to drill a hole. I will try to take a pic tomorrow.

 

[MrGreenJeans]

Why is this done? Water crossings? If so, at what point / frequency / depth - does this become an advantageous mod?


TIA

 

[consalvochris]

Just cheap insurance, the stock breathers only go up to the frame. If they were to get water in the breather, it would go into your differential or transfer case, water and oil don't mix = damage to gears. You could change your diff/transfer case oil after every encounter with water but when you use synthetic oil, either Mobil 1 or Amsoil etc, you would rather not.

 

[lugueto]

Both in the 80 and the 90 series I have both breathers joined by a Y coupling in the engine bay and then a single breather on the firewall. I wouldnt have drilled the body, I wouldve found another way through. Good write up anyway, This is a must if you're gonna be crossing water..

 

[yotasavg]

Great write up! I'm not sure if this will work on the LC since I'm still new to it, but I've used these on my mini Toys with great success: http://www.trail-gear.com/differential-breather

 

[AimCOtaco]

Another important tip is to keep the lines running upward, avoid flat runs and definitely don't leave any low spots where oil would accumulate. Cool oil that accumulates in the lines will effectively close them and that can cause seals to fail due to the build up of pressure or vacuum. Good mods though when done right.

 

[revoked]

Great write up! I'm not sure if this will work on the LC since I'm still new to it, but I've used these on my mini Toys with great success: http://www.trail-gear.com/differential-breather

So these close up the breather completely while still allowing it to contract and expand? I like it.

 

[jonharis]

I did this slightly differently for the rear breather. Instead of the gas cap I ran mine up behind the drivers side tail light assembly. It's a little higher than the gas cap. I removed the light assembly and ran the breather tube into the cavity. Nice hidden installation.

AimCoTaco: good point that others should be very aware of with not having loops or low spots in the lines where oil can accumulate.

 

[yotasavg]

So these close up the breather completely while still allowing it to contract and expand? I like it.

Exactly, worked great for me in the past, I may order some before winter and see if they'll work on the LC. If not, there's a lot of people around who will buy them for their mini. I'm pretty sure it will work though...

 

[Supra88]

Mine run up to the engine bay. Should I be concerned about the long run from the rear diff to the front of the cruiser? I don't see how oil would get up there?

 

[OregonLC]

Mine run up to the engine bay. Should I be concerned about the long run from the rear diff to the front of the cruiser? I don't see how oil would get up there?

You want it to be self draining otherwise it will act like a trap and create a vacuum.

 

[stonepa]

Why is this done? Water crossings? If so, at what point / frequency / depth - does this become an advantageous mod?


TIA

Anything over the top of the wheels. I ran mine up into the headliner just to be safe. If I get deeper than that I'm dead.

 

[Ironman2011]

Great write up! I'm not sure if this will work on the LC since I'm still new to it, but I've used these on my mini Toys with great success: http://www.trail-gear.com/differential-breather

Looking for more feedback on this option from any experienced mechanics. It make sense to me so far but I'm cautious. To me this approach 1) may eliminate the need to drill holes, paint holes, etc. 2) eliminates the worry about low spots in extended tubes 3) prevents ingesting humid air into the into the differential 4) is completely closed (if clamps are tight enough so no water goes into differential even if you cabin is flooded.

I haven't tried to calculate the amount of air in the OEM system nor the temperature extremes to determine the pressure, etc. to know if the proposed system allows enough expansion without the pressure increasing to a magnitude that would exceed the limitations of various seals.

Can anyone come up with any reason why someone wouldn't want to implement a closed system which allows for expansion and contraction?

Thanks for you input!

 

[abuck99]

Keep it simple. Vent to atmosphere near or above the height of the door handles. I ran my rear diff breather up into the fuel filler compartment. Front is routed up and attached to the fire wall. Have not done the TC or transmission- yet.

 

[BEG]

Looking for more feedback on this option from any experienced mechanics. It make sense to me so far but I'm cautious. To me this approach 1) may eliminate the need to drill holes, paint holes, etc. 2) eliminates the worry about low spots in extended tubes 3) prevents ingesting humid air into the into the differential 4) is completely closed (if clamps are tight enough so no water goes into differential even if you cabin is flooded.

I haven't tried to calculate the amount of air in the OEM system nor the temperature extremes to determine the pressure, etc. to know if the proposed system allows enough expansion without the pressure increasing to a magnitude that would exceed the limitations of various seals.

Can anyone come up with any reason why someone wouldn't want to implement a closed system which allows for expansion and contraction?

Thanks for you input!

Those bellows are intended for trail-only rigs that don't see elevated temps from high speed driving. If there's not enough room in the bellows to contain the increased air volume after it heats up, you could be looking at blown seals and gear oil all over the road. Here's a couple of real world results from actual users:
trail gear creeper breather
Trail Gear creeper breather question - YotaTech Forums

With regard to a closed system in general (not specifically the bellows), there's no fail-safe if you get it wrong. There might not be enough play in the system to allow for all the temperature extremes and elevation changes you might encounter. In addition, if you're running an air locker, there's a high probability that you'll get some leak-down over time which will eventually blow out the seals in a closed system.

My opinion is that the extended breather system is best. There's no need to drill holes or paint or anything, nor do you need long runs of hose that would create low spots. I ran my rear diff breather up behind the rear drivers side fender liner and attached it to the gas tank fill hose behind the quarter panel (no need to poke through the fuel filler). The front diff breather was connected to the end of the factory hose and routed up to the passenger side fender, next to the airbox. The trans/t-case breather hoses were joined with a Y connection to a line zip tied to the top of the trans filler tube. All were topped with motorcycle fuel filters.

 

[CleveToy]

Those bellows are intended for trail-only rigs that don't see elevated temps from high speed driving. If there's not enough room in the bellows to contain the increased air volume after it heats up, you could be looking at blown seals and gear oil all over the road. Here's a couple of real world results from actual users:

x2. I had this on the rear axle of my 1998 4Runner and I'm almost 100% sure it's what made the axle seals blow out. PO didn't have a breather, he bought the bellows on on the cheap. His axle seals didn't leak until maybe a month after he installed it. Then I bought it from him and did it this way with no issues what so ever.

Hoping to get this done on our new 100 soon.

 

[mookamatook]

So, I've watched a few videos of the 80 series arb breather install and one on a 105 with a non arb kit. I just bought the arb kit for the 100 series and i'm wondering the following things. I reiterate, 100 series!

I need to breath the front and rear differentials for sure, correct. Should I breath the rear all the way up to the firewall? What is the best routing for this? I've heard that you need to keep the line moving up and not have horizontal runs and I'm not sure I have a solid game plan for getting that rigged up. The front diff should be fairly simple but is there a routing strategy that works best for this? Anyone have photos of where their lines run? Where they zip tied them and how to keep them neat/tidy?

Should I breath the transfer case or gear box? I've heard that those are both other options that are good insurance. Should I grab some more hose and add those to the install? Thanks all!

 

[BEG]

So, I've watched a few videos of the 80 series arb breather install and one on a 105 with a non arb kit. I just bought the arb kit for the 100 series and i'm wondering the following things. I reiterate, 100 series!

I need to breath the front and rear differentials for sure, correct. Should I breath the rear all the way up to the firewall? What is the best routing for this? I've heard that you need to keep the line moving up and not have horizontal runs and I'm not sure I have a solid game plan for getting that rigged up. The front diff should be fairly simple but is there a routing strategy that works best for this? Anyone have photos of where their lines run? Where they zip tied them and how to keep them neat/tidy?

Should I breath the transfer case or gear box? I've heard that those are both other options that are good insurance. Should I grab some more hose and add those to the install? Thanks all!

Keep the hose runs as vertical as possible. I routed the rear up along the fuel filler hose to just behind the filler cap. For the front diff, I routed it up near the air box. For the t case and trans, I used a y-connector and routed them to one breather to the top of the trans dipstick.