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Quadra-Trac / MM Part time conversion kit

17K views 10 replies 5 participants last post by  CJDave 
G
#1 ·
I have some questions regarding the Milemarker Part time conversion kit for the Quadra-Trac whitout the low range add-on unit. I'm trying to learn about this 'mechanism' once and for all....but I really have problems understanding
it - so please help me:

Without part time conversion (as I understand it): When a rear wheel breaks traction the QT sends power to the front axle. When the QT is locked into the E-drive mode via the vacuum switch (glove box), both axles get constant
power always and in E-drive you can not drive on dry pavement.

1. What does the conversion kit do - does it convert from full time 4wd to full time 2wd ?

2. Is it possible to 'switch' between 2wd/4wd driving? Is the switching done by the lockout hubs or the switch in the glove box? If I can switch to 4wd is this only or emergency driving ie. not highway driving ?

3. What spins after the conversion - does the front of the transfer case spin after the conversion ? as well as everything else, out to the (unlocked) front hubs ?

4. If the 'front' is not spinning, what is then the point of installing lockout hubs in front ?

5. If the 'front' is not spinning, how do I keep the parts lubricated and thereby avoid corrosion ?

6. How does the Emergency-drive work after this conversion ?

7. Is it true that this conversion eliminates the need for special lubriant ?

Thanks in advance,

Thomas
CJ7, 1979, 360
/Denmark


 
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#2 ·
1st of all FILL OUT YOUR PROFILE so we know were you are and what you drive... Thang like that...
Answers
1. YES
2. I wouldn't
2a. Both
2b. For 4wd
3. If you engage 4wd. The rear end is the drive axle
4. So the front axle doesn't rotate.
5. Just like every other 4wd. You use it..
6. You get a new sticker that says 2wd or 4wd.
7. Yes

If I knew were you lived I have a QT setting on the floor of my garage with the kit installed w/ 16% overdrive and the low range unit I'll let it go cheep. The unit has less than 10,000 miles on it I'll bet only 5,000...

78 CJ7 304V8,TH400,Dana 300 Twin stick,Custom HD-WT AMC20 detroit locker 4:10,D30 ez-locker 4:10,Built NOT Bought.
 
#3 ·
Wally answered most of your questions in list form. I will answer them as well but in narrative form.

-Everything you said about the QT without a conversion kit is correct. With the conversion kit, you have two choices: 2wd with power to the rear wheels only [switch position to the left] or 4wd with equal power to both front and rear (no differentiation)[switch position to the right or e-drive].
-With the switch to the left only the rear driveshaft turns, the front driveshaft does not turn. If you don't switch to lockout hubs then the front axles will turn all the time but will not be powered since the front driveshaft is not turning.
-Turning the switch to the right engages true 4wd just like the lever does on gear base t-cases.
If you do the conversion, then you don't need special fluid anymore (I use ATF in my converted QT). However, if you don't do the conversion, then you have to use special fluid but you don't have to buy if from the dealer (Crown Automotive makes a replacement fluid that is much cheaper).
-One of the best sources for QT info is ifsja.org and I highly recommend it but beware: you have a cj and it is a FSJ board so respect their knowledge and try not to flaunt your shortwheel base status.
 
#6 ·
According to the ifsja.org site you should shift from 2wd to 4wd travelling at less than 5 mph. You only want enough movement for the mechanism to engage since it splined. I usually turn the switch, get out, lock my hubs, and then wiggle the front driveshaft a little until it locks (then I know I am in). Don't rely on the light in the dash, mine only gives a true indication about 50% of the time.

 
G
#8 ·
Hi again,

Can I conclude that (1) switching to 4wd after a par time conversion is the same as (2) Emergency drive without a conversion ie. equal power to both front and rear and no differentiation ?

Regards, Thomas

 
#10 ·
I'll share a little of my experience with the QT. First, I would not spend the money for the part time kit. You will not improve you mileage enough to justify the cost. If you really want rear wheel drive, just install lock out hubs and shift the transfer case to "emergency drive". This is how mine has been since I installed lockers in both axles.

As for shifting, if the front hubs are locked you can shift to "emergency drive" at any speed in a relatively straight line.

 
#11 ·
/wwwthreads_images/icons/smile.gif Chandon, I'm going to toss you a different kind of ball here so pay attention./wwwthreads_images/icons/crazy.gif The QTs are a pain because of the cone clutches which bind up the drivetrain and actually prevent the unit from going into FWD "Lock" in a very secure fashion, so they pop outa FWD lock quite easily. I have never torn one down that didn't have some evidence on the sliding clutch that it had popped out repeatedly. The QTs don't actually send power anywhere per se, what they do is simply RESIST differentiating. They resist when needed, and also when NOT NEEDED. What we did to make our CJ better in snow and better on pavement was disable the cone clutches. That gave us a fully open center differential and also helps the unit slide into EMERGENCY mode (locked up FWD) easier and more securely. We bored out the cones and then installed a thrust washer between the cone and the differential side gear. We no longer have to use the special fluid, and the cast iron metal filings from the cones no longer contaminates the lube oil. If you want to free up your Jeep and make it run more freely, you can just install locking hubs in front and just unlock ONE HUB. Not both, JUST ONE at a time, and trade off every month. That way you don't inadvertently trash the front differential spider gears./wwwthreads_images/icons/smile.gif One other thing......all QT Jeeps HAVE TO HAVE PERFECTLY MATCHED TIRES. Make a fixture to check the rolling height of each tire and adjust the sixe with air pressure to get them to have the exact same rolling radius./wwwthreads_images/icons/tongue.gif

CJDave
A moonguy-operated Jeep Skunkworks in the "Heartland".
 
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