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Quadratrac???

Discussion in 'Intermediate CJ-5/6/7/8' started by endless expense 45, Mar 21, 2007.

  1. Mar 21, 2007
    endless expense 45

    endless expense 45 Oldsmobile RTI Ramp!

    Stony Creek VA.
    Joined:
    Jul 26, 2005
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    175
    My wife just bought a 79 CJ-7 that has a 304,TH400 an it has the quadratrac set-up.What I was wondering is what is quadratrac and how does it work.I have built many Jeeps this is the first one I have run into and I am baffled.If anyone would take the time to explain this I would be very thankful.:?
     
  2. Mar 21, 2007
    wiley69cj5

    wiley69cj5 Got Mud!

    Parkersburg WV
    Joined:
    Dec 8, 2006
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    26
    quadratrac is a full time four wheel drive system. the tc has a chain and takes special lubricant. some are high range only some have a low range, the shifter is a little lever under the drivers seat. they slit torque 60/40 f/r under normal circumstances, the tc works like a differential. the chain is a can be a weakness they stretch over time.In the glove box is an emergency switch that locks the tc differential allowing you to limp home if you break a driveshaft. My friends always called it granpa four wheel drive becuase you don't have any hubs to lock in. I had a 79 cj7 with a 401 th400 and quadratrac. I put a new chain in it then abused it with heavy right foot and 38 11.00 boggers. I never had a problem with the tc, but i broke a lot of m20 rear ends and d30 front ends. A couple of companies make part time conversion kits for the tc. happy wheeling:)
     
  3. Mar 21, 2007
    endless expense 45

    endless expense 45 Oldsmobile RTI Ramp!

    Stony Creek VA.
    Joined:
    Jul 26, 2005
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    Thanks that helps me understand what it is,I can already tell i'm not gonna like it and I have not picked the jeep up yet.
     
  4. Mar 22, 2007
    fourtrail

    fourtrail Built not Bought

    Carlinville,...
    Joined:
    Jan 24, 2004
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    204
    Don't discount it to soon. A full time t-case is great when you have lockers in both ends. No binding between the front and rear axle, makes trail driving much better. Just flip the switch when you need true 4wd. Just make sure the vaccum to the emergency switch is good and periodically check the chain and they work great.
     
  5. Mar 22, 2007
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Aug 10, 2003
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    Read the article and comments on Flint's page: http://jubileejeeps.org/quadratrac/index.htm

    There were lots of Wagoneers, J-trucks and Cherokees sold with the BW1320/BW1339. It works great, especially in the snow. Most problems are from prior owners that don't maintain it properly (ie use the wrong juice or neglect it). The chain will stretch over time, and needs to be checked occasionally - they usually last somewhere between 60-100K miles. Chain replacement's not hard - get the Morse (Borg-Warner) chain, not a cheapy.

    You can also get help from the Wagoneer crowd: www.ifsja.org/forums
     
  6. Mar 22, 2007
    JeepTherapy

    JeepTherapy Sponsor

    Negaunee, Michigan
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    Jun 29, 2006
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    I used one behind a 401/turbo 400 for a long time. I had more problems with the turbo 400 than I did the transfer case. I moved t he switch from the glove box to the dash so I could reach it when I needed it. I did summers brothers axles and a gear drive locker in the rear and a gear drive locker in the front. With the quadratrac and those diffs it worked very well! I ran 33" tires with it and broke very few parts except the transmission. All of it user induced. The thing would turn all 4 tires on pavement hitting second. That and a kid with a heavy foot just don't go well together.

    Another advantage is lower drive line angles and both diffs offset to the same side.
     
  7. Mar 22, 2007
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
    Joined:
    Sep 23, 2002
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    12,529
    One thing to add is you must use actual quadratrac fluid. DO NOT use anything else. They have a cone-clutch inside them that allows for the differential action front to rear and these are no longer available. Last one I rebuilt I had to tear down 5 of them to get enough parts to make a good one, mostly because of these cone clutches. If you don't use the prescribed fluid the clutches get chewed up. Nickmil
     
  8. Mar 22, 2007
    jd7

    jd7 Sponsor

    Nacogdoches,Texas
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    Mar 30, 2004
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    1,745
    Probably the most useful Jeep I ever owned was a 77 CJ7 w/304 quadratrac setup. It had the low range option with a set of Armstrong tru-tracs on it would just about go and do whatever I ask of it. Good luck:beer:
     
  9. Mar 22, 2007
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
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    Jul 30, 2003
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    8,513
    just wanted to point out one item
    the front driveshaft has a CV (constant velocity) joint
    at the transfer case end, there are 2 u-joints plus the CV yoke
    there should be 3 lubrication points in/around the CV housing
    it takes a needle adapter for your grease gun to lube them
    make sure you lube them faithfully...
    if the CV joint fails and breaks apart, it takes out the side of the T400 transmission case, not a pretty sight to see
     
  10. Mar 22, 2007
    endless expense 45

    endless expense 45 Oldsmobile RTI Ramp!

    Stony Creek VA.
    Joined:
    Jul 26, 2005
    Messages:
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    Thats is all great information almost to much to take in at one time.I think I will give it a shot,the worst thing i can do is break it.I'll be going to get the Jeep tomarrow i'll let everyone know how its is.
     
  11. Mar 23, 2007
    JeepTherapy

    JeepTherapy Sponsor

    Negaunee, Michigan
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    Jun 29, 2006
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    It has been near 20 years since I had my quadratrac set up jeep. Didn't they use auto transmission fluid and then a quart of extreme pressure concentrate I think it was called?
     
  12. Mar 23, 2007
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    No. You should use Quadratrac fluid, either from the DC parts dept or from Crown (TCL-1? something like that).

    You can find recipes for make-your-own QT juice, but they are all based on single-weight motor oil plus friction modifier IIRC. ATF is totally wrong for the BW1339.

    But don't make your own. Use the real stuff - anything else is penny-wise and pound-foolish.

    <edit> Also, the CV problem that Jim mentions is very common in the TH400 Wagoneer, and I guess that applies to the CJ-7 too.
     
    Last edited: Mar 23, 2007
  13. Mar 23, 2007
    JeepTherapy

    JeepTherapy Sponsor

    Negaunee, Michigan
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    Hate it when the memory starts to go. Might have been with the doug nash conversion in it that it needed the ATF. I do remember using the additive though. EPC? I was told to use that with whatever fluid I put in it to help lube the clutches in the diff prior to the conversion. WOW that was a long time ago....

    As for the front driveshaft. It is about an inch from the corner of the transmission. I have caught rocks up in there before. That will also take the corner of the trans.
     
  14. Mar 23, 2007
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
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    if you want to talk early early QT, they used Chevron Aviation oil, a red, thin, non detergent auto trans type of oil
    that didn't last long though, till they came out with QT fluid
    we had an old case of that stuff lying around till the day we closed shop
     
  15. Mar 23, 2007
    endless expense 45

    endless expense 45 Oldsmobile RTI Ramp!

    Stony Creek VA.
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    Jul 26, 2005
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    Ya,ll are making me feel like a Baby every jeep I own is older than I am,and twenty years ago I was only 5 years old.R)
     
  16. Mar 23, 2007
    jeepdaddy2000

    jeepdaddy2000 Active Member

    Eagle Point oregon
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    Mile Marker Still offers a part time kit for these T cases. They are strong, simple to install, and do not require the use of special lube (at about 8$ a quart). If you don't have the reduction unit, I would start scouring the junk yards. They are usually cheap and very simple to install. Also make sure your emergency drive works. Rotten vacuum lines or a bad vacuum motor can leave you in the lurch if you get to the point where you need to lock up the T case.
     
  17. Mar 24, 2007
    endless expense 45

    endless expense 45 Oldsmobile RTI Ramp!

    Stony Creek VA.
    Joined:
    Jul 26, 2005
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    I went and picked it up last night.It does have the lever to switch it to low range beside the drivers seat,I cant get the glove box door to check the switch out it seems to be stuck.I will post more tomarrow I did not get home last night until 10 pm and had to work a 24 hour shift today but sundays coming.Oh and my wife will post pictures hear as soon as I get off work.
     
  18. Mar 25, 2007
    tommycj

    tommycj Member

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    Mar 24, 2007
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    The best thing you can do at this time is get a hold of the shop manual that shows the quadratrac system and all the vacuum lines.
    If you cannot lock the system and activate the light or unlock to shut the light off, it is either the vacuum lines or the diaphragm on the unit.
    The diaphragm is available new from some sources, but a used one is acceptable.
    If the unit starts to groan, it is time to change the fluid, but first get on dry blacktop and do some figure 8's. This sometimes solves the problem.
    The early units had some problems, but were basically due to the fact that many of the dealerships new nothing about the operation.
    The quad unit is quite stout. They used to use it in the Baja 1000 in the early 70's on a set-up with the 401. Speeds up to 140. At least held up for 1000 miles.
     
  19. Mar 26, 2007
    Fat Va. Boy

    Fat Va. Boy New Member

    Crimora, VA.
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    Feb 18, 2007
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    Been there - Done that. Enough to cause an overload of :beer:
     
  20. Mar 26, 2007
    Fat Va. Boy

    Fat Va. Boy New Member

    Crimora, VA.
    Joined:
    Feb 18, 2007
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    I can hook you up on the shop manual stuff. I have a reprint of the factory manual for the 1979 (year specific) Jeep vehicles that I can probably copy and get to you somehow.
     
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