Quadratrac : Good or bad?

[toyman]

This is my first time posting on what appears to be a very good message board for a Jeep fanatic such as myself.

I've owned several CJs but have never owned one with the stock AMC automatic quadratrac. I've located an extremely clean bone stock*
1977 CJ 7 304 c.i. with 65000 actual miles that I'm considering purchasing. I need some expert advice on the duability of this driveline for sand duning, trail rides, some light rock climbing and lastly used limited for snow pushing with a 7 ft. plow.

*I was told it had an upgraded transfer case & front hub lockouts.

How can I tell if transfer case was indeed upgraded?

Is this a good driveline?????????

Also should I favor a fairly clean stock 94 Wrangler YJ with 4 Liter H.O. 5 sp. with 125000 miles instead of the CJ 7 for the same money instead???

Thanks for your input on this difficult decision I'm trying to make.

 

[jay79cj7]

funny stuff...off topic

I have a quadratrac. I don't think too many on this board do. They are also common on the full size jeeps and trucks made between 73 and 79. You can find info on these Jeeps at ifsja.org. I have posed as a wagoneer owner on that board before for help. 8)

The quadratrac was one of the first full time 4wd transfer cases out there. There is what is basically a limited slip differential that joins the front and rear driveshafts. It has a dubious reputation for several reasons. From what I have read: Other full time 4 cases had made a bad first impression. Most cases were gear driven, and this was chain driven. Most had tough steel cases, and this was aluminum. These things gave the impression of weakness, but modern transfer cases are built this way. And the worst of all, it was picky about fluid. You had to have a special jeep approved fluid or it wouldn't work right. If given the right fluid, it worked well. Here is an article that I had bookmarked.
http://www.jpmagazine.com/techarticles/23658/

I would bet big bucks that your "upgraded" transfer case is a part time conversion. This is pretty common for the quadratracs, and a previous owner put it in mine. The differential sprocket is replaced by a new part that converts the case to part time 4wd. Some of these kits had a smaller sprocket than the stock one, resulting in an "overdrive." The kit saves some gas because you only power 2 wheels, and you don't have to use the expensive fluid. Standard ATF works. This is why you have locking hubs in the front, to unlock the front drivetrain so you don't have to spin it while you drive. Stock qtracs did not have locking hubs. They were permanently locked.

If you have the part time kit and you want full time 4wd, you will have to crack open the case and replace that sprocket. You can't buy them anymore, but you can get a rebuild for about 400 bucks I have found.

These cases were sold with and without low range. There will be a low range shifter in the cab on the floor if you have it I think. Mine doesn't have one, but I got one that I will put on someday. They are literally a bolt on unit, so that can be upgraded easily if you want that.

The TH400 auto transmission is a very tough, reliable, and well liked transmission from what I have read. They were used in much bigger vehicles than CJs and behind much more powerful engines, so it should be tough enough to handle whatever you throw at it.

If you want any more info, let me know. I have read a whole bunch about this case and taken one apart, but I am by no means an expert.

Comparing the CJ and YJ:
http://www.off-road.com/jeep/swb/articles/specgrid.htm
CJ: 150 HP, 245 ftlbs
YJ: 180 HP, 220 ftlbs

I love CJs, but a newer YJ will be less rusty and probably more reliable. Parts will probably be easier to come by, especially used ones.

Good luck.

 

[Bounty__Hunter]

Get the YJ:

• Stronger Frame
  More reliable with Fuel Injection
  Better 4wd system with parts more readily available
  Newer Everything
  YJ's are cool, it's hip to be square

 

[jps4jeep]

Hey welcome to the board. That CJ sounds real nice! but I would also go with the YJ, due to what bounty said. YJ's are great on and off road in any trim. I have seen bone stock YJ's do things that mst other 4wd's would cringe at! The CJ's are also very good off road, but there is also a larger maitance upkeep, carb tuning, weaker frame and shackle mounts, and CJ's are prone to rust!

Just my $.02

 

[toyman]

Thanks for input guys!

I've checked out the sites you provided Jay. The article about the quadra-trac was very interesting as were the specs on both the CJ & YJ.

I'm still uncertain on which way to go. I'm kindá partial to the CJ7 as I'm an old school type of guy & really like ease of mods. to the V8 for increased performance but the I also like the YJ for the stronger frame, less prone to rust, all the new tech. stuff with fuel injection etc. & parts availibility.

 

[jay79cj7]

Yeah, I like the CJs too, which is why I went that route. If you really like the fuel injection, and like to spend money, there are kits you can buy to retrofit your engine. Also, there are carb upgrades out there that people seem to really like. My carb works fine for me (and did for everybody with a jeep until the late 80's), but I have the 258, not the 304.

I don't know why a YJ frame is stronger. I had never heard that before. The rust thing is definitely true. CJ bodies weren't galvanized, but I think YJ's were. Check the floor pans. Not sure about the frames. If the frame isn't bad on the CJ, you can always clean it up and coat it to protect it. Make sure to check the back of the frame where the shackle mounts and where the front of the rear spring mounts also. That's where mine is the worst. I am not sure where you live, so rust may not be as big an issue for you as it is in the snow states. There is a paint called POR15 that is supposedly amazing at stopping and preventing rust. If mine were worth saving I would use it.