How can you tell if quadratrac is locked

[Kedler]

I recently bought a 79 Wagoneer and I'm working though plenty of issues. It's my understanding that the differential in the transfer case is locked by vacuum control. Given the state of the vacuum hoses everywhere else I would guess this isn't working. My question is if this hose is leaking or disconnected will the quadratrac be locked in emergency mode or will it remain in normal four wheel drive? Am I safe to drive around and test stuff out before this vacuum issue is fixed, or am I putting the four wheel drive at risk?

[REDONE]

I wouldn't worry about during new-to-me shakedowns and test runs. Running around with the case in edrive is "hard" on the drivetrain, but if it causes some kind of catastrophy in a limited number of short trips, there were other problems at play. Besides, the clutches get really sticky if they sit for a while which basically "locks" the tcase anyways. Then it breaks free with a bang &shudder so violent you think you broke something. Then it sticks back again like nothing happened.

Have you done your parking lot figure-8s yet?

[Kedler]

Haven't done anything yet but got around the block. I don't have much power past 20mph. Once I get that sorted out I plan on doing longer faster test drives. Just don't want to eventually run it up 55 and break something.

[bigun]

Jack up the front and try to turn the wheel

[tgreese]

If you remove the vacuum lines, the transfer case will stay in whichever mode it was last shifted into, full-time or locked (emergency drive aka "e-drive.") You can read about the shifter in the TSM or here - http://jubileejeeps.org/quadratrac/index.htm The complete '79 TSM is available free to read and download here - http://oljeep.com/edge_parts_man.html This will answer many of your questions about your Jeep.

There is more discussion on the Jubilee Jeeps page, and plenty to read in old posts about the Quadratrac. https://www.bing.com/search?q=site%3Afs ... quadratrac and https://www.bing.com/search?q=site%3Aif ... quadratrac

If it's locked and you drive on pavement, you will get tire chirping and binding/bucking when you go around corners. This is worse than the "stick slip" that is mentioned above, where the clutches get sticky and you need to exercise them to make them smooth.

[Kedler]

Thanks for the help guys.

[DustinLangston]

When I bought by 79, someone had bypassed the vacuum actuator and locked it into 4x4 using a bunch of bolts to hold the shift arm in the lock position. Didn't see it until I opened the transfer case to change the chain. I thought for the longest time that I just had stuck cones. But nope.