Transfer Case Lines Issue


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I have a 4-door, 1979 Jeep Cherokee. It has a 360 engine, an automatic TH400 transmission with a Quadra-Trac transfer case. It is one of those all-time 4-wheel drive vehicles.

I had a transmission shop work on it fixing leaks on both the transmission and the transfer case. They replaced the transmission pump and seal plus the output shaft seals for the drive/propeller shafts related to the transfer case. Obviously, they had to remove them to replace the pump and seal.

The issue -- After I got the vehicle back from the shop, I discovered that there were two open steel tubes located on the passenger side at the rear of the engine that were not connected to anything. Transfer case fluid was leaking out of one of the tubes onto the exhaust manifold and blowing smoke. One of the tubes was pointed upward and the other was turned 180 degrees at its end to point downward.

I have the Jeep shop manual for the vehicle. (It is also online at ''.) I couldn't find any documentation about these tubes or any photographs of them. I focused on the transmission and the transfer case sections of the manual when searching for information.

I went online and found relative information via a few forums. They were Cherokee Forum, Jeep Forum, and Wrangler Forum. From what I understand, rubber carburetor fuel lines needs to be connected to the two open steel tubes and to those are connected breathers. (Or connect both rubber tubes to nipples on a three-prong tee and put one breather on the tee's third nipple.) The names for the breathers mentioned in the forums were "breather cap", "breather creeper", "breather fitting", "vent fitting", and "vent."

I have attached three image files for reference. Note that the photo images are not for my 1979 Jeep, but I believe that they are compatible.

Is this correct? Thanks in advance for any help.


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In the images they are vent tubes. They should not have fluid in them. The only way they would is if there was too much fluid in the trans or transfer case.

Also consider the metal lines may be a trans cooler.


On TJ's the lower part of the radiator is a trans fluid cooler.

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Thanks for the response. Some responses and questions --

1) Well, one of the vent tubes definitely has transfer case fluid coming out of it. It is visibly leaking and it's not transmission fluid because, as you know, the difference of the smells of transmission and transfer case fluids is quite different.

2) The transfer case fluid started leaking out of one of the vent tubes immediately after I got the Jeep back from the transmission shop.

3) Is it possible for there to be too much fluid in the transfer case since the fill/drain plug is horizontal to the case? Even though transfer case fluid is heavy as a 50- or 60-weight fluid, if there was too much fluid, any extra fluid should immediately drain out of the plug prior to being able to insert the plug.

4) Yes, one of the lines is a transmission cooler since there are three lines located between the firewall and the engine and there are two lines coming out of the transfer case. (I found the third line when putting rubber fuel hoses on the other two lines onto which I'm going to put breather valves.)

5) Yes, there are two transmission cooler lines that connect to the bottom of the radiator.

My guess is that the transfer case line that is leaking transfer case fluid is the one that needs to have a breather valve attached to it. The other two lines -- one from the transmission and the transfer case -- do not need breather valves.

Your transfer case should have two vacuum lines routed to a dash mounted switch. Have you located those?
Your transfer case should have two vacuum lines routed to a dash mounted switch. Have you located those?

If there is a dash mounted switch, I am not aware of it. Questions about it --
1) Is there a standard location for it?
2) What is its purpose?
3) Would a dash mounted switch relate to the issue in my original post -- Why is transfer case fluid leaking out of a tube connected to the transfer case?


Thanks for the responses and the images. I now understand what you mean by a dash mounted switch. I had forgotten about it until you mentioned it. I haven't determined the two lines that feed to the emergency drive switch located in the glove box/compartment. Hopefully I will determine it tomorrow, following the three tubes feeding out from the top of transfer case and determine where they end up.

Meanwhile, I'm searching for diagrams that disclose both where the other two tubes located between the engine and the firewall originate from and where the two other tubes on the top of the transfer case end up.

I have located three tubes that feed out of the top of the transfer case. I see from the diagram that two of them feed to the dash mounted emergency drive switch. I wonder what would happen if the shop that worked on the transmission mistakenly hooked up the vent hose to one of the two connections for the emergency drive switch.

By the way, in order to make sure that I'm searching for the correct information and to potentially help anyone provide assistance, I took photos of both the transfer case ID and the low reduction unit ID. They are 13-05-107-903 and 13-06-065-901, respectively. I realize that people in the group are probably already aware of this information.



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I spoke to a person at a local auto repair shop that specializes in drive trains who seems very knowledgeable about transmissions systems, especially ones with transfer cases. The things that he mentioned might be the reason(s) for transfer case fluid to be leaking out of the vent tube were the following --
1) The transfer case is overfilled
2) The transfer case is getting too hot
3) The shop put in either the wrong fluid or poor quality fluid
4) Add limited slip friction modifier
5) The three tubes are connected wrong
6) It might be necessary to add anti-foaming fluid

A) I checked the fluid level. It's okay. So, '1' is not possible.
B) I don't know why '2' could occur.
C) Regarding '3', the shop owner showed me the bottle that contained the transfer case fluid. It had "TCL" stamped on it, so it was transfer case lubricant. But it was a generic manufacturer, not from a dealer such as Ford or GM. So, they might have put in either the wrong fluid or poor quality fluid.
D) I am going to follow up on '4'.
E) I will do '5' when I do '4'.
F) If '4' doesn't work, I am going to follow up on '6'.

I have done a lot of research since my last posting on March 7th. That includes perusing Jeep-related forums, perusing Borg Warner transfer case-related forums, speaking with employees at Jeep/Chrysler/Chevrolet/Dodge dealerships, speaking with employees at parts stores, and speaking with employees at junk yards. As a result, I have learned quite a bit about the external goings-on with transfer cases.

Here is some general information related to the issues discussed above --

1) The transfer case is not overfilled
2) The transmission shop put in "Crown Transfer Case Lubricant TCL-1"
3) I added limited slip friction modifier
4) I located the two vacuum lines that connect to the emergency drive switch
5) I have not added an add anti-foaming fluid -- I cannot find it anywhere

Here is some specific information related to the issues discussed above --

'2': A person recommended buying transfer case fluid made by either GM or Ford. He stated that the Borg Warner 1305 transfer case (in my Jeep) requires a higher quality product as opposed to a more generic brand. However, on the back of the Crown bottle, it states "This lubricant is intended to be used in Borg Warner type transfer cases, such as the Quadra-Trac, 1979 and prior." So, this is the correct fluid and can't/shouldn't be the cause of the problem.

'3': There was no difference and transfer case fluid continues to leak out of the vent tube.

'4': The two emergency drive vacuum lines are located next to the transfer case vent tube between the back of the engine and the fire wall. They are not connected to anything. Also, from what I've learned, not having the emergency drive hoses correctly connected cannot be the cause of transfer case fluid leaking out of the vent hose. But I'm not a transmission person, so I'm open to ideas about why the unconnected hoses could be creating the problem.

The transmission shop that worked on my Jeep examined it for the third time. They didn't do any work on it and, instead, recommended that I attach a metallic fuel filter to the end of the fuel line hose that is attached to the end of the vent tube. He stated that they have used that strategy before and it has worked. I bought a plastic fuel filter and attached it. The result was the leak was magnified. I believe that the reason for the magnification is that the fuel filter created a venturi effect.

I spoke with a person at a junk yard/parts store who has been in the transmission industry for 20-plus years and he stated that he believes that the transmission shop, the owner who he knows, has a good reputation for working on transmission. But they must have made a mistake when working on the transfer case. He said that this is probably the reason because working on this particular type of Borg Warner transfer cases is very different than working on other transfer cases. In particular, he believes that they didn't install the seal(s) correctly when attaching the transfer case to the transmission. If this is the case, he said that pressure would be passing from the transmission into the transfer case and the extra pressure is causing the transfer case fluid leak. I don't know if this is the situation, though, because there's no evidence of transmission fluid accompanying the transfer case fluid that's leaking out of the transfer case vent tube.

Summary: It appears that the reason for the problem is that the transmission shop made a mistake. So, I'm planning on taking my Jeep back to them for the fourth time and ask them to fix the transfer case fluid leaking out of the vent tube.

Thanks in advance for any responses,

Is it possible to tell if there were any ATF in the leaking fluid from the transfer case? The transfer case lube is often ATF or close enough to it you can't see a difference.

Has the transmission fluid level dropped?
Thanks for your response. In return ...

I cannot see or smell ATF in the leaking fluid. But as you know, the T/C fluid is darker and stronger smelling than ATF fluid. So that makes it harder to see or smell ATF in the leaking fluid. What I am going to do is attach a metal container to the firewall and direct the fuel hose into it in order to collect the leaking fluid. Then, I should be able to answer your question better.

The transmission fluid level has dropped a little bit. But I believe that it is due to other leaks that the transmission shop didn't successfully fix. I believe that if transmission fluid was leaking into the transfer case, then the transmission fluid level would have dropped significantly more.

Regarding issue number '2' in my previous message, I am going to proceed with replacing the existing fluid with fluid that states that it is specifically designed for Borg Warner transfer cases. Hopefully, that will eliminate the leaking problem.

Not trying to sound condescending but how many times do you take the transmission back to a shop that never gets it correct? At some point find another place that can fix it and document it well enough you could back charge the shop that messed it up.


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No insult taken. And you're correct -- I should take the Jeep to another shop and have the original shop pay for it. What a hassle it would be, but that might be the solution.

Meanwhile, I attached a breather cap to the end of the fuel line hose. As expected, the transfer case fluid still leaks out of it. But significantly less is being emitted. Next, I will change the fluid and see if that solves the problem. And I will attach a container to collect any fluid that leaks out of the tube. If not, then I will contact the original shop about them paying for another shop to fix the problem. I hope that I won't have to get the Bureau of Automotive Repair and a lawyer involved.

then I will contact the original shop about them paying for another shop to fix the problem. I hope that I won't have to get the Bureau of Automotive Repair and a lawyer involved.

I'd be shocked if any shop agreed to pay for another shop to look at or fix their work. Normally You'd foot the bill and then try to recoup thru small claims court.
It would be a hassle. I had a shop change rotors, pads and rotate tires. They insisted a caliper was frozen because they could not move the piston by hand. When i let them know how much i know about vehicles, and that story was BS, they finished the job. They stripped the caliper bolt and cross threaded a lugnut.
I had to have the lug burnt off and the caliper replaced by another shop. They filled out an affidavit and took pics plus returned the damaged parts.
When i confronted the initial shop owner to pay the damages, he brought out his entire crew. Like we were going to fight. In the end he paid the bill.

Before BBB check out the federal exchange commission.

Using app

Thanks for the story about your experience with a shop that worked on your vehicle and the advice about contacting the Federal Exchange Commission. But is the Federal Exchange Commission involved involved in automotive repair disputes?

I followed through on my plan. I changed the fluid in the transfer case, but not the low reduction unit. (I'll explain below why I didn't change the fluid in the low reduction unit.) It didn't work -- fluid still leaks out of the transfer case vent tube. As a temporary workaround, I (1) Created an overflow reservoir, (2) Attached one end of a fuel hose to the vent tube, and (3) Inserted the other end into the overflow reservoir. I hope that this doesn't prevent the transfer case and low reduction unit from properly venting heat and pressure. With the overflow reservoir, it still leaked, but only about one ounce of fluid was in the reservoir after driving the Jeep a total of 100 miles including going up some long steady highway hills which provided the same necessary pressure as my previous test to determine if the vent tube would leak fluid.

I wonder if the reason for the vent tube still leaking, either with or without using the overflow reservoir, is due to the following ...
After I finished changing the fluid in the transfer case, I found a Web page that explains that it's necessary to loosen all five low reduction unit housing bolts in order to drain the unit. Now, I'll drain the fluid from the low reduction unit and, maybe, this will completely eliminate the leaking problem.

Question: I wonder why Borg Warner created a drain plug for the transfer case and not for the low reduction unit? Assuming that there's a gasket/seal between the body and the "plate" of the low reduction unit, I would think that it's possible that the gasket/seal could get damaged or destroyed by loosening the bolts and peeling back the plate.

By the way, the new fluid that I put in is by Crown Automotive. The bottle has a maroon-colored label on the front stating, among other things -- "For Jeep Vehicles" and "Transfer Case Lubricant TCL-1". On the back label, it states among other things -- "This lubricant is intended to be used in Borg Warner type transfer cases, such as the Quadra-Trac, 1979 and prior."

Does anyone have any thoughts about these points?
Sry that's the federal trade commission

Useful info here

Have you verified no cracks in the cases?
Verified both vent tubes are clean and clear?
What temp does your engine run?
Are you sure your trans cooler is working? Color of fluid after a few hundred miles? Try adding an additional trans cooler.
What rpm are you at on the highway or during most of your trip?
Lifted with larger tires and geared low?

If your engine runs hot it heats the trans oil and in turn the transfer case oil. Both trans and transfer case oil will come out of the vent tubes. Same if the cooler lines are blocked.

Do you ever see it leaking? Is it bubbling out? If so is it like a improperly filled power steering unit? They foam and boil out everywhere if air is not bleed properly.


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