Quadra-junk

I have a 1976 Jeep cj-7 that has a factory 360, auto, with the Q-trac. I want to eliminate the Quadratrac tranfercase for a selectable transfer case. Does anyone know what tranfer will swap directly in? Or who sells an adapter? Any help would be appreciated.

 

How about the MileMarker part-time conversion?

There are no other transfer cases that will bolt in. You can convert to a Dana 20 from a Jeep with a TH400, but you will have to take the TH400 completely apart to swap the tail shaft.

 

Another possibility is to use parts from a Chevy and go to some transfer case with a NP pattern. I think Chevys had TH400s with passenger drop NP208s or NP205s for a while. The NP208 would likely fit, or you could use a D300 if the splines match. Then convert to a centered D44 from an intermediate and get rid of the offset M20 - double win!

You can convert the TH400 to almost any TC you are willing to spend the money for the conversion kit. All conversions will require disassembly of the transmission to replace the output shaft. A Dana 18 conversion will let you keep your offset M20, but I would not go that route.

Why not keep the BW1339? It's not junk. Most negative comments are from people who are passing on inaccurate second- or third-hand information. Most failures are due to improper or inadequate maintenance. The folks at www.ifsja.org/forums have lots of experience in keeping these transfer cases working. You might check it out before you discard the BW1339.

 

:iagree:

 

Don't forget that you have an offset rear diff and if you swap to a t-case with a centered output it will create a really funky and most likely unworkable driveshaft angle. The only offset output t-case Jeep used was the Dana 18 but it would be tricky to adapt it to the TH400.

The only people I know who think the BW1339 is junk have either never owned one or don't understand how they work. They work really well when properly maintained and are pretty simple to work on.

 

Great information thanks, I am planning an axle swap for the jeep, and would like to be able to unlock the front end as it will be sitting on 37's. Maybe just putting some lock out hubs will acheive my goal. Thanks again!

 

You need a part time kit if that is your plan.

Just adding lockout hubs will burn up the transfer case quickly. The quadratrac is more or less a posi, and if one side is unloaded, it will eat the clutches.

 

Lets take this line by line...

No CJ-7 ever came out with a 'Factory' 360.
The largest engine ever offered in a CJ was the 304.

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The transmission used at that time was the Turbo-Hydro Matic Model 400.
The THM-400 is the all time 800 pound gorilla of automatic transmissions, and is capable of holding back well over 500 horse power and 500 foot pounds of torque.

The draw back to that transmission is.... Weight.
There is a lot of internal 'Heavy Metal' to hold back that much energy, and the weight of all that metal will eventually cause it to need rebuilt.
At the first hint of 1st gear or Reverse 'Issues', have the transmission rebuilt with a new bushing in the center support, or a new center support.

The issues with 1st/Rev is a bushing that wears out, and allows a forward clutch drum to contact the center support 'O' rings.
Once the 'O' rings fail, then you are wearing metal on metal, and the rebuild REALLY gets expensive!

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Q-Track, or 'QuadraTrac' is a Jeep generic term for a Borg Warner transfer case.
(Borg Warner 1305 if it does NOT have a low range lever under the front right edge of the drivers seat on the transmission tunnel.
Borg Warner 13-39 if it has low range.)

The Borg Warner transfer cases you are talking about are vacuum operated, full time cases.
They are 3/4 Ton cases, and are VERY STRONG when they are properly set up.

The biggest problem these cases had was people letting the vacuum lines rot,
Or not keeping track of the chain tension/condition inside.

They DO NOT lend themselves to 'Lockers' in the differentials, so serious off roaders do not care for them.
Your hubs will not have Lockouts attached to them.

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Easier said than done.

You have the option of using a International Scout Dana 20 transfer case with the 'Texas 5' bolt pattern,
The same bolt pattern you have on your BW T-case.

You have the option of converting your BW T-case to PART TIME operation with a Part Time kit the others have mentioned.

You have the option of buying a rather expensive adapter set and running about any transfer case you want to.

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There is no direct swap in for your application.
Dana 20 has a centered output for the rear differential,
While your differential is off set to the passenger side.

That obstacle alone would steer me towards either a new (centered) rear differential and transfer case swap,
OR...
Just doing a part time kit and putting lockouts on the front axle.

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http://www.novak-adapt.com/

http://www.advanceadapters.com/

Those two are probably your best bet for adapters.