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post #1 of (permalink) Old 09-27-2006, 08:13 PM Thread Starter
 
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Emergency Drive Control ?

Hello everyone, been a while since I've been on here. Could somebody tell me what it does, and how it works? My brother in law just bought a 76' CJ7, 304v8, automatic with Quadra-Trac xfer case, and I was wondering about the emergency drive control. It's in the glovebox, just a little toggle rod, which way engages it, clockwise, or counter? And does it cause the front axle to freewheel or is it fulltime 4wd? There's 2 rubber vacuum lines coming from it running into steel lines that run to the xfer-case and intake manifold, and they turn back into rubber lines that go to a solenoid on the xfer-case. What is the purpose of the emergency drive control? Thanks for any answers, and please give me your opinion on the automatic and Quadra-Trac combo. I've never had any dealings with anything but a manual tranny in a Jeep, so any info would be greatly appreciated. Thanks.
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post #2 of (permalink) Old 09-28-2006, 02:23 AM
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Re: Emergency Drive Control ?

While I can't help with which way does what, but the rest I can answer. The Quadra-Trac is not a bad Tcase but it is not the best. The biggest problem is that the chain wears and streches and starts to skip. The chain wears relatively fast as all the engine load for both front and rear axles goes trough the chain. It also needs special lubricant that is very expansive. The Auto transmission will be a TH400 which is regarded as bullet prof.

Provided the case has not been modified to part time it will drive both front and rear axles at all times IE full time four wheel Drive. It uses a Limited slip style differential to prevent binding when driveing on the road. Unlike most full time transfercases the springs in the Limited slip are setup to give more torque to the front something like a 60-40 split. The "emergency drive" simple locks the differential so that equal rotation goes to both front and rear like a part time case. "emergency drive" lets you drive with one drive shaft removed. Be aware that there is a kit that converts the case to part time, so that may have been installed. Also, someone on this board did a modification to remove the front torque bias and liked the results. I can't remember who try asking LEVE it may have been him, if not it was talked about atleast 4 years ago likely more). There may also be a floor lever, which will engage an optional low range unit that extends from the back of the case. These were a factory option.
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post #3 of (permalink) Old 09-28-2006, 07:02 AM
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Re: Emergency Drive Control ?

This is a good thread to read on the Quadra-Trac transfer case:

CJDave's Trieste on the Quadra-Trac Transfercase
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post #4 of (permalink) Old 09-28-2006, 08:57 PM Thread Starter
 
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Re: Emergency Drive Control ?

Thanks guys for the info, LEVE, your link to a past topic was very informative. So as far as I can tell, my brother in law has a pretty decent set-up. Thanks again. [img]/ubbthreads/images/graemlins/cool.gif[/img]
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post #5 of (permalink) Old 09-29-2006, 08:33 AM
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Re: Emergency Drive Control ?

It is a good transfer case. It and the body and frame are all that are left original on mine. It has 216,000 miles on it. It just needs a chain about every 40-60k miles. Chain is about $120 and fluid is about $16 for 2 quarts. Takes a couple hours to change.

I now have a TH700r4 in front of mine. I moved my vacuum switch from the glovebox to the left side of the dash between the door and headlight switch.
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post #6 of (permalink) Old 09-29-2006, 09:27 PM Thread Starter
 
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Re: Emergency Drive Control ?

Will, I saw your picture in LEVE'S past link to the topic, where you had moved yours to the drivers side, (is that a pull/push switch?) and me and my brother in law were talking this evening about getting a 3 port vaccum switch and moving his to the center or the driver's side of the dash so he can access it easier. Will it hurt to run the x-fer case in either position until we get a chance to hook my vaccum gage to the vacumm pot on the case and see which way the glove box switch is set up for locked or unlocked? From what I gathered from the link that LEVE gave last night, the case either runs in a 60/40 split (unlocked), or a 50/50 (locked) split. Either way, the axles are still limited slip. Correct? And also, I saw that you can get a 2WD conversion for the case, but you can also get part time conversion hubs for the front axle? Wouldn't it be easier to convert the front axle instead of the case? Just wondering. Thanks. [img]/ubbthreads/images/graemlins/confused.gif[/img]
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post #7 of (permalink) Old 09-29-2006, 09:39 PM
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Re: Emergency Drive Control ?

Click on the picture to a fab up a mechanical shifter.

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post #8 of (permalink) Old 10-03-2006, 01:01 PM
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Re: Emergency Drive Control ?

[ QUOTE ]
(is that a pull/push switch?)

[/ QUOTE ]

No, it is the factory switch from the glove box. It is just a vacuum switch that directs vacuum to one line or the other to the transfer case. It is about a 1/8 turn switch.

[ QUOTE ]
Will it hurt to run the x-fer case in either position until we get a chance to hook my vaccum gage to the vacumm pot on the case and see which way the glove box switch is set up for locked or unlocked?

[/ QUOTE ]

Yes, it will hurt to run with it locked on the street. You don't need to get a vacuum gauge to hook it up. Just put the switch to unlocked, start the jeep and see which rubber line at the transfer case has vacuum by putting your finger over the end. Hook the one with vacuum to the rear nipple and the other to the front nipple.

[ QUOTE ]
From what I gathered from the link that LEVE gave last night, the case either runs in a 60/40 split (unlocked), or a 50/50 (locked) split. Either way, the axles are still limited slip. Correct?

[/ QUOTE ]

No. When locked, the front and rear outputs are locked together like any other part time case in four wheel drive. It is only limited slip when unlocked.

[ QUOTE ]
I saw that you can get a 2WD conversion for the case, but you can also get part time conversion hubs for the front axle? Wouldn't it be easier to convert the front axle instead of the case?

[/ QUOTE ]

There are a couple options here.
You can convert the case and not use lockout hubs. This would be like the TJs and flatfenders. The front driveline is still spinning but no being powered.

You can use lockout hubs and not convert the case. This is what I have done. For street driving, I lock the transfer case and unlock the hubs. The front driveline is still turning but it is not connected to the wheels.

You can use lockout hubs and convert the case. With this, the vacuum no longer locks/unlocks a differential but engages and disengages power to the front driveline.

This really is a simple transfer case. Not including the low range, there aren't a lot of parts to it.
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