Transmission/Tcase equalizing hose

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Oct 13, 2013
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Bryan, TX
I know that most of us have, or have had, the migrating Tcase oil issue.
Man-a-fre seems to be out of stock and piecing them together isn't cheap.
One of our members has come up with a high quality alternative to the Man-a-fre part. Shipmag is selling these in the vendor classifieds, but he is a 40/55 guy and didn't have a 60 to check it on. I decided to pick one up last week and it is a great piece of kit.
He has multiple lengths available, but I went with the 17.5". Probably could've gone shorter, but it isn't a big deal.

https://forum.ih8mud.com/threads/transmission-to-transfer-case-bypass-hose.794901/



I recommend picking one up if you are in the market.
Thanks shipmag!
 
It's not impossible to make these either. I used old aircraft hose I had. The fitting size is BSP, to 1/4 JIC. I just cannot remember the size going into the pan. But it's possible to use B-nut style hose and make something work. I'd buy one though first if you want to save the effort.

But once these go on, I doubt any oil other than residual goes into it, as once the air is equalized the pressure is equalized. I used to get the trans overfilled from the t-case. now it doesn't change at all. I've removed the hose an it isn't full of oil. So most of the issue is fixed by equalizing the pressure INMOP.
 
It's not impossible to make these either. I used old aircraft hose I had. The fitting size is BSP, to 1/4 JIC. I just cannot remember the size going into the pan. But it's possible to use B-nut style hose and make something work. I'd buy one though first if you want to save the effort.

But once these go on, I doubt any oil other than residual goes into it, as once the air is equalized the pressure is equalized. I used to get the trans overfilled from the t-case. now it doesn't change at all. I've removed the hose an it isn't full of oil. So most of the issue is fixed by equalizing the pressure INMOP.

Interesting perspective. I had the trans and tcase out to do the clutch recently, and of course replaced the seals when reassembling. But now I'm tempted to install the hose just on the chance that the equalization of pressure would prevent the seal from failing. Of course, the original went 300k+ miles before it failed, so perhaps I'm solving a problem that doesn't exist...
 
If you pull the transmission plug and oil comes out you have a failed transfer case seal. Cheap insurance rather than driving around with low oil level in the transfer case. After all how often does on pull the fill plug on either the transfer case or transmission to check the levels.
 
It's not impossible to make these either. I used old aircraft hose I had. The fitting size is BSP, to 1/4 JIC. I just cannot remember the size going into the pan. But it's possible to use B-nut style hose and make something work. I'd buy one though first if you want to save the effort.

But once these go on, I doubt any oil other than residual goes into it, as once the air is equalized the pressure is equalized. I used to get the trans overfilled from the t-case. now it doesn't change at all. I've removed the hose an it isn't full of oil. So most of the issue is fixed by equalizing the pressure INMOP.

The stainless steel braided hoses I make up for mudders and do as a group buy have a teflon sleeve between the rubber hose and the braided part of the hose to prevent heat from the tail pipe damaging the rubber hose.
 
Hey @shipmag I want in on this. Would I Paypal you or something. I have a diesel hj60 with the 5 speed. Should I just measure to see what would fit best? My transmission is 3" longer than a typ. H42. Will probably measure to see what I need.
 
I have the man-a-fre kit, and it does the job, but I would have bought this setup had I known. For the clean look alone...but it also looks slightly easier to remove to check oil levels.
 
I have one 17.5 hose left. If you want more of them it will be awhile before I order more, as I just placed an order and have 5 12.5 hoses I need to get rid of before I place another order. Unless we can get ten of you who want the 17.5 length hose to do another group by and I would place the order. I am really doing this as a favor to mudders as I dont make a whole lot off these to buy a bunch and sit on them unless there is a big call for them from you FJ60 guys. PM me if your interested. And as one guy said you dont want this hose if you have an automatic transmission..
 
I have three 12.75 hoses left. I am willing to do a group buy for the 17.5 or if you need a different length now would be the time to order. I usually order a couple extra hoses. I can order any length you need when I do a regular order. The longest one I did was 26.00 inches. The shortest is the standard 12.75 the FJ40 needs. Send me a PM if your interested. The 17.5 is $65.00 unless the vender increases his price without telling me.

new price
You need to measure from the fill plug of the transmission to the fill plug of the transfer case. It will be either a 12.75 or a 17.5. $63 for a 12.75 or $65 for a 17.75. Add $8.30 for shipping inside the USA, for shipping outside of USA PM for shipping price. Send as a gift on paypal to avoid paypal fees or add $4.30 more.
 
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Interesting perspective. I had the trans and tcase out to do the clutch recently, and of course replaced the seals when reassembling. But now I'm tempted to install the hose just on the chance that the equalization of pressure would prevent the seal from failing. Of course, the original went 300k+ miles before it failed, so perhaps I'm solving a problem that doesn't exist...

I read in another thread that the pressure relief valves, plugging up, are what cause the seal to leak. If you didn't replace those when you had the trans out, you might have a leak again soon.
 
This is what I have experienced:

The vent cap on the top of the transfer case is a one-way spring loaded poppet valve. Air can flow out of the transfer vent but can not be sucked back in. This is to prevent the ingress of water. Each time the car is started and driven, the transfer heats up, the air inside it expands, and the vent purges the air. No problem.

When the engine is shut down for the day, the TFR eventually cools and a vacuum develops as the hot air in the TFR contracts. Since the TFR breather is (or should be) a one way valve, this creates a vacuum in the TFR case. If the seals in the TFR are working as they should, you should hear a hiss of air sucking into the transfer case when you slowly release the TFR fill plug when the engine is cold in the morning after being driven the day before.

If no air is heard being sucked in, the seal/s is not sealing perfectly.

If the seal is a bit worn, it will allow a bit of oil to be sucked from the tranny to the TFR upon cooling. Oil migration from a H55F to → the TFR usually occurs when the car is driven on lots of short trips with worn seals.

If the car is driven longer miles with a worn TFR seal, the spinning input gear can pump transfer oil → to the transmission.

>>>
This being the case, based on my personal experience, a transmission to TFR bypass hose can provide a dangerous false sense of security and F*&k up the transmission if the hose is installed and forgotten... thinking that everything is hunky dory, where in reality you may be grinding your transmission to bits.

Since (in my experience) the installation of one these hoses MUST NOT replace the frequent oil level checks necessary when the TFR seal is worn.... Installation of said hose actually becomes more of a pain than a convenience, since the removal of the hose to check the oil levels is always more of a messy chore than just unscrewing a fill plug.

So, after saying all this, the bottom line is, even with an overflow hose:

You Still Gotta Check Your Oil Levels FREQUENTLY.
 
Havent heard from the FJ60 crowd in a while. To find out if you seal is gone take the fill plug out of the transmission. If oil comes out it can only come from one place the transfer case which means your seal is gone. If it is and you dont want to pull the transfer case to replace the seal then buy one of my by pass hoses and eliminate the oil being sucked out of the transfer case. Pm me if your interested. I have three 17.5 long hoses and it seems thats what some guys are buying.
 

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