Questions re: Rear Differential Breather Mod
 

My first post so forgive any missteps. I know there are threads about the rear diff. breather mod. But I have a few separate questions that are all related to the mod, but not easily searchable on other threads. Here goes:
1: The ARB Rear Diff. Mod kit is on Amazon, however it says it isn't compatible with my truck (2019 SR5). Is this wrong? It should fit yes?
2: The ARB kit comes with a plastic hose/line. Living in the North East and seeing a good amount of cold weather should I use a rubber fuel line instead of the supplied plastic one? Or is the ARB one rated for cold weather?
3: Can someone somehow share the best route for the line? I am very new to DIY mechanics and I don't want to run it or zip tie it to anything I'm not supposed to. Also hoping for the easiest route available ie: no extra drilling or removing & replacing parts or trim that may be in the way.
4: Are there any symptoms of having water in the rear diff? The whole catalyst for this mod is having recently learned that the recent wheeling I did, wherein the puddles were up to the bottom of my doors, may have been a good way to get water in the rear diff. I have used the 4x4 since and not had anything sounding or feeling strange. How concerned should I be? Might take a few days or a week to order the kit and find the time to do the install. Should I drain and replace sooner? Or will it be okay to wait so that I only have to borrow my friends garage and remove my spare the one time? I plan on changing the diff oil when I do the mod ideally.

Thanks for any and all help guys and gals!

Rear Differential Breather Mod For Dummies

I’ll spoon feed you.


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Drain and refill the rear diff, then you will know if water got in.

IMO -- Save some $$ and work, don't use the ARB kit. Use rubber fuel or vacuum line and go up to the fuel filler, not all the way up front.

I was not sure what size line to use, I took the fitting to an Auto parts store and we found one that fit.

What thread pitch fitting did you use for the rear diff?

Wanderlost Overland has a good video on YouTube not using the ARB kit

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I used the Toyota parts from the sticky section on external mods in the diff breather section. I stopped inside the fender, did not go to the outside as in the post. No diff oil smell, easier to install.

Rear Diff Breather - Toyota 4Runner Forum - Largest 4Runner Forum

With my off-road jeep, I used carburetor fuel filter to cap the diff extension. They allow air to pass through. Will not allow water to pass.

Thanks All!
 

Sorry it took so long to say thanks for all the replies. I am having trouble navigating this forum specifically when it comes to seeing replies to my posts and replying when someone does reply to my posts. For example, I have no idea if this reply will be directed at the last poster, or be a general reply, or am I replying to myself?
Anyway...
I just found all your replies now and thanks again. I read the "for dummies" post and had already watched that cute couples (Wanderlost methinks?) YouTube video on the mod. Neither answered my question about the ARB hose in colder weather. Well... I have already installed the ARB mod as is. Guess I'll check on it periodically. I considered doing the mod without the ARB kit, but I am super noob to anything mechanical (I drive a 30 ton truck and operate heavy machinery for a living... go figure) but am wanting to learn. If there were no such thing as bolts stripping and if I had smaller hands I think I would have gotten interested long ago. Anyway my "noobness" made me go with the complete kit and it was a small challenge to run the line with the fear of putting it too close to anything it shouldn't be close to. But I did it. Ran it over the gas tank skid brackets, behind a few heat shields with other line assemblies, and up into the engine bay.
Now I'm tripping over a lift. But that is another story...

It's been 4 years since I wrote the Mod For Dummies on the ARB Breather. Mine is still going strong, traveling over 65,000 miles from -40 degrees in upstate Vermont, cooking daily in this swamp we call Florida and the desert Southwest. Check the line periodically but I don't think you'll have any issues if you are far enough from the heat shields.

You will want the ARB 170112. That’s more than likely the one you are looking at, but yes, it will work just fine.

I ran my hose along the bottom of the frame (driver side) up into the engine bay. Just make sure its tucked up high for any off-roading or things that could snag on it (like brush). Also remember to have slack in the line, not a ton, but enough for allowing the body to flex. Zip ties are your friend here. As long as you aren’t on the exhaust, or something rotational you’ll be okay.

You shouldn’t have any issues with the hose it comes with. I have had mine on in the heat and ice cold. No issues as of yet. Wouldn’t hurt to check once a year or so to make sure it’s okay.

If you feel water got in, just drain the rear dif. It’s extremely easy. Pop off the fill plug, pop off the drain plug. Let it drain. Clean and put in the drain plug, fill it up until it starts to drip out, clean and put the fill plug in, and done. It will cost you about $70 tops to do. Better than a near rear.

Also I would HIGHLY recommend doing the rear locker if you have one. There is a breather on that as well that sits about 3” higher. If you are careful enough you can technically split the hoses into one line, however I wasn’t able to make that work.

Extra hose: https://www.amazon.com/gp/product/B077WJCMNF
Connector for rear dif locker breather (if you have one, otherwise won't apply to you): https://www.amazon.com/gp/product/B000CO7AOS/

Thanks for the mention!

In our opinion, the plastic line you would get in the ARB kit will become brittle in extremely cold temps. Rubber line is your friend and, it's much easier to route.
In our video we show tying in the diff lock breather as well. With your SR5 you likely don't have a rear locker? If that's the case you won't have to worry about that.
Also in our video we run our new breather line all the way up front, under the hood. No need to go through the extra work of routing the line if you don't want to. Placing the breather next to the gas cap like others have said will work just fine. We don't recommend placing the breather behind the access panel in the interior. If you've ever smelled used diff fluid you'll understand why. :)
All you really need to have is;
* The fitting we show in the video that will take the place of the stock breather in the diff. I believe it's a fuel line fitting for a Camry. We show the part number in the video.
* A few feet of rubber fuel line.
* A couple hose clamps.
* Zip ties.
* For the breather you'll need something small enough so the gas cap door shuts. Maybe someone else can lead you in the right direction there.

Here's our video: https://youtu.be/1MFW8YK9dx0

Thanks again all!
 

Thank you all so much for taking the time to help out!

No locker... Yet.
And $70 would have been a dream. The OEM Toyota rear diff fluid on Amazon was $45 per liter. X 4 (I believe it will take just over 3) and I spent about $220 for the fluid, new gaskets (washers), and a pump to get the fluid in the pumpkin.

Thanks for all the info!

Yow. $45 per liter. Other gear oils are much less expensive. I used Amsoil 75W90 in the squeeze bottle for about $18 each. Local auto parts store, not from Amazon.

Remember you can use 75-90 instead of the Toyota stuff. Most dealerships use 75-90 and not 75-85 as the manual says. I did 75-90 in all of mine and have had zero issues.

Regardless what you spend is still less than a rear going bad.