RV Repair: Tent trailer cable repair, crank handle, four holes

Question
I have a 1978 Jayco pop up that has a broken cable. Three lifts elevate and the 1 rear has to be maually pushed up. Can you give me a quick schooling on this subject?
Thank you,
Norm

Answer
Norm,
    Jayco has been using basically the same lift system since they began production back in the 60's.  Where you insert the crank is the winch.  Around this winch is the main cable.  At the end of the main cable there is a square plate with four holes in it.  You should be okay to this point since three of the corners are rasing.  In those four holes there should be four eyebolts mounted to it with 4 small cables, one to each eyebolt.  Once you remove the access panels that are covering these you should be able to inspect everything.  You may see a broken eyebolt, the eye pulled open on an eyebolt, or an eyebolt with no cable or just a small piece of cable.  If not then the problem is probably at the rear of the pop-up so you will need to remove those access panels to inspect back there.  You may see one of the pushrods (looks like a long spring) pulled out of the floor track that it rides in.  This usually occurs between the floor track and the curved corner track at the sidewall of the camper.  If that isn't the problem then I would follow the cable back towards the front, it may have broke at one of the wall or floor pulleys.  

       Basically this is how the system works.  As you turn the crank handle in the winch it wraps the main cable around the spool pulling the square plate with the four eyebolts and cables that control each corner of the roof.  The cables are routed to each corner through a system of pulleys.  When they get to the corner they then run inside the floor track to the end farthest from the corner they are raising.  That end of the cable hooks into a drive slug that rides inside the floor track.  As the cable is pulled that drive slug pushes the pushrod (long spring) out of the floor track into the curved corner track that goes from the floor up the sidewall and into the lifter post.  At the end of the pushrod there is a drive rivet that is semi-round.  It rides in a socket in the lifter post and as it pushes the lifter post up it telescopes out in three or four sections depending on the size of the camper.  

      I hope this answers your questions and good luck with the repair.

Darren