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my first JEEP! w/exlpoding transfer case!! :(

2K views 24 replies 15 participants last post by  jeepdaddy2000 
#1 · (Edited)
Always wanted a Jeep.....randomly saw one for sale. impulsively purchased it.

It is a 1976 CJ7 Quadratrac. Original 304 rebuilt with all edelbrock parts. bored .30 over and .10 under. rebuilt engine had around 700 miles when I puchased it about 3 weeks ago. tranny was rebuilt and had about 40 miles on it when i bought it. the jeep was completely restored from the ground up. has a 9,000 lb Warn Wench....custom built front and rear bumpers. has a sweet air compressor set up on one of the front cylinders with a switch in the glove box. plus a ton of other goodies....but anywho.... my problem....

was driving down the street and the quadratrac transfer case... started to make a grinding noise....then it made an unholy sound of death...in which apparently the chain locked up and snapped(exploded), blowing 2 sides of the transfer case out!! Freaking could have made me cry like a little girl!! other than that....she has performed wonderfully.

Does anyone have a clue as to how or why this would happen to a transfer case?? The Chain was replaced when when transmission was rebuilt, so it wasn't an old chain. Actually....the transfer case itself looked like it was brand new. huh...someone help!







 
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#3 ·
I think I would check and see if the tranney has a warrenty on the job. Coud be worth looking into. Just my .02 good luck jc
 
#4 ·
I see maryland tags, hello from a fellow maryland cj'r. anyhow I would check to see if its warrantied in any way, could get lucky, if not then obviously it will need to be replaced, good luck if you need a hand let me know
 
#5 ·
Should be able to locate a Qtrac pretty cheap. Most prefer a gear driven TC. If you find one that needs a chain, I have a brand new one you can have for the price of shipping. Some guy stopped at my house once and asked me, "Hey.. you're the Jeep guy right?" I told him I liked Jeeps and he gave me some left over parts from an old project. The chain is hanging in my garage taking up space....
 
#7 · (Edited)
meatloaf said:
Always wanted a Jeep.....randomly saw one for sale. impulsively purchased it.
That's the way to do it :thumbsup:

So the prob:

meatloaf said:
The Chain was replaced when when transmission was rebuilt, so it wasn't an old chain
That's something that I would expect to happen when the chain stretches so my first thought is the chain was installed wrong or they used a wrong or used chain.

It's possible it's another problem elsewhere in the driveline but doesn't seem likely. Since the case is toast you could replace it with another Quad or put in a Dana 20 or maybe an Atlas or??

I would find out who rebuilt it and go from there. I think they missed something.

And get some pics of the carnage







 
#8 ·
I assume the PO had receipts confirming the t case rebuild. If so and it has a verified 700 miles on it, might try taking it back to the shop and see what they say. While Q trac chains will stretch causing a nasty ratcheting sound, they rarely break. The fact you heard a grinding sound might indicate a shaft support bearing gone bad. If one of the shafts were to drop, it might cause chain failure. Without Pict's it is hard to tell what went wrong.
 
#10 ·
As the quadratrac has a cast aluminum case, it can explode if the chain comes apart. Sounds like somethings wrong here, I would go back to the shop that rebuilt the tranny/case.

One of the maintaince checks on the quadratrac is to check the chain length. If you get the case fixed or replaced make sure you know how to check the chain length to prevent this from happening again. Very simple check. The quadratrac case also takes a special fluid, so find out what the shop and PO have been using in the case.

My quadratrac has been running for 32 years, never had it explode on me.

Jim
 
#11 ·
thanks for the replies guys. i'll get some pics of the carnage as soon as i get over to my moms where i have it parked. from what i have been told, only the tranny was rebuilt. it was taken to a shop that is no longer open, and they only had a one year warrenty which has since expired. far as i know nothing was done to the transfer case except the replaced chain. I have been in contact with the guy who did most of the work on the jeep while it was in the "states"(originally from HI). He has been very helpful and is tracking me down another qtrac case.

i hope it all gets sorted out soon.
 
#12 ·
Time to buy a 'New' T-case...

This would explain why the tranny shop is closed!

Anyway, not too may ways to screw up a TH-400 transmission, either they work, or they don't most of the time...
And any 7 thumbed buster can build a TH-400,
(I'm proof of that! Made a living for 30 years doing that stuff, so that proves anyone can!)

Anyway, there are two kinds of "QuadraTrack" Transfer cases use behind the TH-400 Transmission in AMC vehicles...
One, the most common to SWB Jeepers (Short Wheel Base) is the Borg Warner 1339.
Here is a picture of the gear reduction version, Borg Warner p/n 1339


------------

The other type has NO gear reduction, just (sometimes) four wheel drive.
If your gear reduction survived, you can bolt it onto one of these pretty easy, given you find a rebuildable Borg Warner p/n 1305.
----------------------------

A good opportunity for you right now is to get QuadraTech's FREE catalog for CJ's and 4 Wheel Drive Hardware's FREE catalog with exploded views of parts so you can figure out what is what...

Here are some links that might give you some idea of what you are looking for.
http://www.thejeep.com/onlinecatalog/p132.htm
http://www.novak-adapt.com/knowledge/quadratrac.htm
http://www.quadratec.com/?sgsc=GOOGLEQUADTECH&gclid=CKiB9IbahY8CFRJZUAodESNJwg
http://www.4wd.com/
 
#15 ·
Metloaf:

I am looking at a 1976 wagoneer with a 360, th400 and a quadratrac transfer case. All is supposed to be working. I want the motor, so if you need a quadratrac case let me know, I can get this waggy for a low price and would sell the case to you if you need one. Several others are interested in the Dana 44's front and back, so maybe the waggy would be a good deal for us all.

Shippiing is always the issue, but let me know if oyu need this case.

Jim
 
#16 ·
Shane k said:
By chance was the transfer case converted to part time 4wd? If so, if it accidently was switched to 4wd while in motion it will cause the case to explode.
Won't cause it to explode, but it will grind like crazy.
 
#18 ·
jfwireless said:
Metloaf:

I am looking at a 1976 wagoneer with a 360, th400 and a quadratrac transfer case. All is supposed to be working. I want the motor, so if you need a quadratrac case let me know, I can get this waggy for a low price and would sell the case to you if you need one. Several others are interested in the Dana 44's front and back, so maybe the waggy would be a good deal for us all.

Shippiing is always the issue, but let me know if oyu need this case.

Jim
i'd definitely be interested. let me know what you find out.
 
#23 ·
I'm not sure, but I think that the quadratrac transfercase uses a pump for lubrication. The amound of RTV used on that case is excessive. It's possible that some of that sealant got stuck into the pump pick-up, reducing lubrication.

The only true way to diagnose is to disassemble the case.
 
#24 ·
Looks like the chain came apart, you may never know why. Could have been an old chain, or a cheap after market replacement, or something in the drivechain.

Next time when you hear a noise, make sure you stop.

Make sure you get a Borg Warner chain when you rebuild this or another case. Borg Warner made this transfer case for Jeep.


Jim
 
#25 ·
algmmech said:
I'm not sure, but I think that the quadratrac transfercase uses a pump for lubrication. The amound of RTV used on that case is excessive. It's possible that some of that sealant got stuck into the pump pick-up, reducing lubrication.

The only true way to diagnose is to disassemble the case.
No pump in the Q trac. The chain lubes the T case.
You need to crack the case to find out more. It is possible that a bolt wasn't tightened or another piece of foreign matter was loose and fell between the chain and sprocket. This might account for the grinding noise as well. Luckily, these are easy cases to work on.
 
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