Quadra Trac

fryedaddy

Well-Known Member
Joined
Mar 22, 2005
Location
Winston-Salem
I'm looking at a jeep with a Quadra Trac transfer case and need some info.

Are these transfer cases any good? I'm pretty sure they are chain driven - any problems?

I don't have any experiance with this type of transfer. I'm used to dana 20, 300 etc. any assistance would be appreciated.
 
Never had any problems out of mine when I had it. I believe they operate on a series of clutches. Just remember to lock it in when you go off-road. Locking knob should be in the glove compartment (on a CJ) IIRC.

They do have a weird offset for the rear driveshaft, requiring a rear axle with the diff to one side. May be something to consider if you plan to swap axles. You will have to swap the quadratrac for a D300 or other transfer case.
 
Quadratrac transfer cases have unique mounting pattern and input shaft. Any other transfercase you use will require an adaptor. Q-Trac cases were pretty good for what they were designed for but are not well supported by the aftermarket or well used in trail riding/rock crawling.
 
For day to day driving, they are fine. Keep the fluid in them (special fluid with graphite additive for the slip cones) and remember what you got. They are full time 4x4, can be converted to part time, but by the time you do it, you could have picked up a D300 and a centered rear axle.

The glove box vacuum switch locks front and rear with no slip.

They all use a Th400 which is identical internally to a GMTH400, but they use an output shaft that is so long it actually sticks out past the rear bumper and drags the ground (just exaggerating a tiny bit) However this tranny is useful with nothing but a Qtrac. I assume (Ive heard you can but never tried)you can change the output shaft and tail housing and make a normal th400 out of it, but why? At that point pick up a used tranny if you are swapping anyway.

One final warning, if you someehow blow a font shaft or bust spider gears STOP or your Tcase will look like the one in my metal bin (chain hanging out the side of it.)
 
What are you going to put it in? What tranny?. A friend of mine has a TH-400 w/Q-trac from a FSJ he'd like to sell. Let me know and I'll set you up.
 
They are pretty stout t'cases. There's nothing wrong with them as long as they are still in good shape. Unfortunately, they are not rebuildable due to limited parts availability. There are still plenty of good used ones out there, though.

The chains do stretch over time. Replacement chains are still available and pretty easy to replace. If the chain stretches too much it can jump and blow the case apart. You can check the slack through an inspection port on the bottom of the case. 1/2" is good, 1" you're in the danger zone.

The center diffs are prone to wear, especially if the right fluid is not used (non-detergent 30W oil with a posi additive) and are not serviceable. Not really an issue because you can lock it with the e-drive for off road. The e-drive is vacuum actuated and you'll probably need to replace rotted vacuum lines to get it working. Drive it in tight figure 8's (in normal mode) and make sure it doesn't have a stick-slip problem. You can feel it if it does.

Also, some QT's had no low range. If you have a low range lever on the left side of the tranny tunnel under the seat you're good to go. If not, no big deal, it's about a 15min job to install one.
 
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