Rear shaft not spinning

[CJ7 Jeeper]

Hey everyone, I recently bought a '79 CJ7 with Quadra Trac. I was finally able to get it on the road and I noticed it riding really hard. At first I thought that's the way it rides, but it just seemed like it was moving in front wheel drive only. Well, I jacked it up in the front and back. When the front hubs are locked and I put it in drive, all 4 tires spin( front spin really fast and back only spin when I give it gas). When I unlock the hubs the front drive shaft spins but nothing happens in the rear. The rear drive shaft doesn't even move. I read a lot about QT and I guess I get it. I think as long as you unlock your hubs, it would be in 2WD? Anyone have an idea why my rear isn't turning?

Thx, Vinny

 

[Lumpy Grits]

See if this helps.
Jeep® Quadra-Trac I® 4WD System Explained - YouTube
LG

 

[CJ7 Jeeper]

Thanks Lumpy Grits. I've seen that clip before. It's not that I don't get QT, it's more that my rear drive shaft isn't spinning. Also, I forgot to mention, my QT vacuum lines are not hooked up. Don't think that has any bearing on my rear drive shaft though...it should spin with my QT in regular or emergency mode, right?

 

[mtnwhlr]

I don't know alot about the Quadra-Trac but I don't think they came with Lockout Hubs. Sounds like someone has tried to change it to a normal 4WD instead of full time 4WD.

 

[Lumpy Grits]

I don't know alot about the Quadra-Trac but I don't think they came with Lockout Hubs. Sounds like someone has tried to change it to a normal 4WD instead of full time 4WD.

Me thinks your 'rite' about the hubs.
OP-Do you have the low-range lever in the glove box??
LG

 

[CJ7 Jeeper]

The tub was changed, no lever by driver seat or anything in glove box. I have the selector for QT though, just not hooked up. So I might have a different front axle? How is that affecting my rear?

 

[CJ7 Jeeper]

I read that hubs were an option in those QT years.

 

[hdgapeach]

Don't know much about the QT but I do know the tire with the least traction gets the power. Aftermarket locking hubs on the front guarantee the front gets all the power when the hubs are in "free" mode.

You also need your vacuum lines and switches in good working order before you can determine if you have internal issues with the Transfer Case .

I googled the topic and got a hit on another forum that has some good info that may help with your problem. Hope posting the link ain't treadin' on forum ethics:
quadratrac issue - JeepForum.com


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[Lumpy Grits]

Post pictures so we can see what you have.
LG

 

[CJ7 Jeeper]

Thx everyone, I'll post pics.

 

[CJ7 Jeeper]

Sorry it took so long, here are some pics.

I have hubs..

 

[CJ7 Jeeper]

front axle..

 

[CJ7 Jeeper]

QT..which I wired up and replaced vacuum lines. I'm hearing a leak at my switch so that's the next thing to replace. Also, I noticed my QT vacuum diaphragm only has 1 nipple on it. Isn't it supposed to have 2? I ordered one anyway, I guess a week before I get that. I have more pics in my gallery if needed.

 

[CJ7 Jeeper]

Thx to all. I figured it out. I dropped my Transfer Case and opened the vacuum window. PO jammed the vacuum diaphragm tube in and the shifting fork was too much toward the rear to engage the gears. My gaskets and replacement vacuum parts are still on order, but problem is solved, thx again

 

[hdgapeach]

Cool! Glad you got it figured out. And thanks for the detailed described update.

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