Help With Rear Diff Breather Mod

M

Maz

New member
I read the comments in the linked thread, given in the original thread about the review guy in the red Limited who almost dug himself into a hole when driving across a "frozen" pond. It became clear my having to drive across running water on trails at or near the beach occasionally, means a rear diff breather mod is a must.

I wouldn't feel even close to comfortable trying to do this. That is even if I did happen to have all the proper tools, which isn't clear. Does anyone have a suggestion where in the So. Cal / Orange County area to look for someone competent to do this mod??

Thanks in advance for any help, I really appreciate it.
 
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I don't know if the threads would fit but have you thought about something like a creeper breather? they are completely sealed and allow for expansion/contraction.
 
92-SR5 said:
I don't know if the threads would fit but have you thought about something like a creeper breather? they are completely sealed and allow for expansion/contraction.
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What's the reliability? Also I think if you do get a small amount of moisture in the axle a full breather or check allows it to escape. Probably still better than the stock check valve.
 
Swarty said:
What's the reliability? Also I think if you do get a small amount of moisture in the axle a full breather or check allows it to escape. Probably still better than the stock check valve.
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Mine have held up to lots of abuse so far with zero issues. If all your seals are good you shouldn't have to worry about moisture getting in there.
 
Easy project and requires no more tools than a screwdriver, a wrench and a knife. I custom made a simple bracket for mine, but you can just zip-tie the filter as well.

All parts and details are in my build thread below.

Okki
 
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Maz said:
I read the comments in the linked thread, given in the original thread about the review guy in the red Limited who almost dug himself into a hole when driving across a "frozen" pond. It became clear my having to drive across running water on trails at or near the beach occasionally, means a rear diff breather mod is a must.

I wouldn't feel even close to comfortable trying to do this. That is even if I did happen to have all the proper tools, which isn't clear. Does anyone have a suggestion where in the So. Cal / Orange County area to look for someone competent to do this mod??

Thanks in advance for any help, I really appreciate it.
Click to expand...

clin9383 said:
This mod is quite simple. Here is a write up by a fellow member. Good luck.
http://www.toyota-4runner.org/5th-gen-t4rs/150158-rear-diff-breather-mod-complete.html
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That's my thread referenced in the above link. I assure you, you have the skills required to do this modification. It's easy peasy! Give it a shot - if you have any issues we'll walk u through it.

David
 
Canazes9 said:
That's my thread referenced in the above link. I assure you, you have the skills required to do this modification. It's easy peasy! Give it a shot - if you have any issues we'll walk u through it.

David
Click to expand...

David,
I just read your thread on your breather mod .Wondering what was the purpose of running the hose in the cab and then back out again when you could have just followed the fuel filler line up on the outside.Seems like alot of extra work and not sure what gain. I remember you were originally talking about running it into the tail light arae and would need it in the cab for that.

I've had mine zip tied to the fuel filler tube for almost 4 years with no problems but have it just behind the fuel door rubber on the inside rather then poking out sort of like this one in the mod stickies......http://www.toyota-4runner.org/5th-gen-t4rs/81938-rear-diff-breather.html
There's a piece of removable plastic in the left rear wheel well to access it. I use a breather filter though to keep out dirt rather the stock valve and changed it after a couple of years.
 
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harper7 said:
David,
I just read your thread on your breather mod .Wondering what was the purpose of running the hose in the cab and then back out again when you could have just followed the fuel filler line up on the outside.Seems like alot of extra work and not sure what gain. I remember you were originally talking about running it into the tail light arae and would need it in the cab for that.

I've had mine zip tied to the fuel filler tube for almost 4 years with no problems but have it just behind the fuel door rubber on the inside rather then poking out.There's a piece of removable plastic in the left rear wheel well to access it. I use a breather filter though to keep out dirt rather the stock valve and changed it after a couple of years.
Click to expand...

At the time I was doing it I couldn't figure out how to route up the fuel filler line all the way up to where I have it. It really was pretty easy and painless to route it the way I did it. I read [MENTION=1913]hoeftm2002[/MENTION] 's thread and it seemed easy so that's the way I did it.

That's not the stock one way valve, but a Toyota 2-way breather just like on the front diff. I've seen people put filters on them, but I've never understood the point. Yes, they breathe but there is very little air flow in/out and no throughput. I just got through changing the front diff fluid on my 2 Tacomas - 75k on my '12, 2nd fluid change on my son's '07 at 150k. Fluid in both was clear and looked good, they're using the exact same Toyota 2 way breather inside the engine compartment.

David
 
Canazes9 said:
At the time I was doing it I couldn't figure out how to route up the fuel filler line all the way up to where I have it. It really was pretty easy and painless to route it the way I did it. I read [MENTION=1913]hoeftm2002[/MENTION] 's thread and it seemed easy so that's the way I did it.

That's not the stock one way valve, but a Toyota 2-way breather just like on the front diff. I've seen people put filters on them, but I've never understood the point. Yes, they breathe but there is very little air flow in/out and no throughput. I just got through changing the front diff fluid on my 2 Tacomas - 75k on my '12, 2nd fluid change on my son's '07 at 150k. Fluid in both was clear and looked good, they're using the exact same Toyota 2 way breather inside the engine compartment.

David
Click to expand...

IS there a reason you went with a two-way instead of using the stock one way and relocating it after removed? Io have the union and was just going to reuse the stock one way.
 
Canazes9 said:
At the time I was doing it I couldn't figure out how to route up the fuel filler line all the way up to where I have it. It really was pretty easy and painless to route it the way I did it. I read [MENTION=1913]hoeftm2002[/MENTION] 's thread and it seemed easy so that's the way I did it.

That's not the stock one way valve, but a Toyota 2-way breather just like on the front diff. I've seen people put filters on them, but I've never understood the point. Yes, they breathe but there is very little air flow in/out and no throughput. I just got through changing the front diff fluid on my 2 Tacomas - 75k on my '12, 2nd fluid change on my son's '07 at 150k. Fluid in both was clear and looked good, they're using the exact same Toyota 2 way breather inside the engine compartment.

David
Click to expand...

I went with the filter because it was recommended for a high flow, zero back pressure, zero vacuum breather for my air lockers so it doesn't suck gear oil back up in the air lines when I unlock them.
This is the ARB Differential Breather Kit (170112) they recommend but most with air lockers just go the mini air breather when I did my research as it's cheaper and still gets high flow and always open.ARB also gives a good explanation of why we need to relocate our rear one regardless of the type of breather used in that link.
 
mfregeau20 said:
IS there a reason you went with a two-way instead of using the stock one way and relocating it after removed? Io have the union and was just going to reuse the stock one way.
Click to expand...

People have used the stock 1 way valve and it generally works. There are 2 ways you can get water in your rear diff:

1) Water tops the 1 way valve when it is screwed into the pumpkin in the factory location. If the one way valve has gotten trash in it or fails in some way, water gets in. Relocating the 1 way valve higher would obviously eliminate this concern.

2). A differential reaches normal operating temperature through routine driving. As the differential heats up the vapor space expands and a small portion is vented through the 1 way valve. The (relatively) hot diff now plunges in to (relatively) cold water, quickly cooling and drawing a vacuum. The 1-way valve works as per design and keeps all water (and air) from re-entering the pumpkin. If the vacuum is strong enough, water can be sucked in through the seals. The differential doesn't even have to go low enough in the water to submerge the 1-way valve, 'cause the water isn't coming from the valve, but through the seals. Relocating the stock 1-way valve with a long length of hose actually helps with this problem also as the long length of hose can collapse a little with the vacuum and relieve the pressure on the seals somewhat. Same concept as a creeper breather, but not as effective.

Toyota used a 2-way breather for the front diff. If I'm going to go to the trouble of relocating the breather I'm going to install a real breather. I don't remember the exact costs but it was literally a couple of dollars at the Toyota dealership.

David
 
harper7 said:
I went with the filter because it was recommended for a high flow, zero back pressure, zero vacuum breather for my air lockers so it doesn't suck gear oil back up in the air lines when I unlock them.
This is the ARB Differential Breather Kit (170112) they recommend but most with air lockers just go the mini air breather when I did my research as it's cheaper and still gets high flow and always open.ARB also gives a good explanation of why we need to relocate our rear one regardless of the type of breather used in that link.
Click to expand...

That makes sense! Never understood the need for a filter till now, thanks.

David
 
Canazes9 said:
People have used the stock 1 way valve and it generally works. There are 2 ways you can get water in your rear diff:

1) Water tops the 1 way valve when it is screwed into the pumpkin in the factory location. If the one way valve has gotten trash in it or fails in some way, water gets in. Relocating the 1 way valve higher would obviously eliminate this concern.

2). A differential reaches normal operating temperature through routine driving. As the differential heats up the vapor space expands and a small portion is vented through the 1 way valve. The (relatively) hot diff now plunges in to (relatively) cold water, quickly cooling and drawing a vacuum. The 1-way valve works as per design and keeps all water (and air) from re-entering the pumpkin. If the vacuum is strong enough, water can be sucked in through the seals. The differential doesn't even have to go low enough in the water to submerge the 1-way valve, 'cause the water isn't coming from the valve, but through the seals. Relocating the stock 1-way valve with a long length of hose actually helps with this problem also as the long length of hose can collapse a little with the vacuum and relieve the pressure on the seals somewhat. Same concept as a creeper breather, but not as effective.

Toyota used a 2-way breather for the front diff. If I'm going to go to the trouble of relocating the breather I'm going to install a real breather. I don't remember the exact costs but it was literally a couple of dollars at the Toyota dealership.

David
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I think I get it, when you cool the rear diff off quickly with a 1 way value it will pull in cooler air anyway it can. With the 2 way valve it allows for air to be pulled in there rather then a seal. I got the union you had listed on your post and passed on the other cause I mistakenly though it was the stack valve. I will go back and get the 2 way when I got off my hump and buy some gas line to relocate. Thanks for the crash course.
 
mfregeau20 said:
I think I get it, when you cool the rear diff off quickly with a 1 way value it will pull in cooler air anyway it can. With the 2 way valve it allows for air to be pulled in there rather then a seal. I got the union you had listed on your post and passed on the other cause I mistakenly though it was the stack valve. I will go back and get the 2 way when I got off my hump and buy some gas line to relocate. Thanks for the crash course.
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You got it!

David
 
It looks like my thread helped flesh out some questions that obviously needed answering. In the meantime I'll bump this back up in the hopes to get a referral.

While I have no doubt that for many people here a breather mode would be simple, the fact I couldn't really follow some of posts clarifying how some people did them tells me it's not for me. Moreover I simply don't have the time to deal with it.

The part I sure did get was that while it may never come into play, if you do get water reverted into your system the damage can be serious. Moreover since it's 100% guaranteed that I'll be out of the country if and when this damage would ever occur, makes it even more imperative to do the mod.

Any suggestions for someone, or place, in Southern California who can do the rear breather mod? I'd really like to get this handled.

Thanks.
 
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Maz said:
It looks like my thread helped flesh out some questions that obviously needed answering. In the meantime I'll bump this back up in the hopes to get a referral.

While I have no doubt that for many people here a breather mode would be simple, the fact I couldn't really follow some of posts clarifying how some people did them tells me it's not for me. Moreover I simply don't have the time to deal with it.

The part I sure did get was that while it may never come into play, if you do get water reverted into your system the damage can be serious. Moreover since it's 100% guaranteed that I'll be out of the country if and when this damage would ever occur, makes it even more imperative to do the mod.

Any suggestions for someone, or place, in Southern California who can do the rear breather mod? I'd really like to get this handled.

Thanks.
Click to expand...

Maz,

I understand the trepidation. This isn't skilled labor and you may have a tough time finding a shop that does this because the vast majority of folks wanting this modification will do it themselves. My best suggestion would be to see if you can find a member that lives close to you that would be willing to come help - you buy the frosty cold adult beverages...

For an inexperienced, non-mechanically inclined person this will take at most a couple of hours. With a little help from someone that has done it before, less than an hour.

David
 
Why the extra effort to isolate the valve in the gas tank fill compartment or inside the tool area? Toyota ran the front breather valve up the firewall. Is there no where else to gain a bit of elevation without going inside the vehicle? Just curious.
 
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