If the gearbox is stripped your only alternative is to manually push it in.
I have done it several times. Its lots easier if you have 2-3 pushing and caution those helping to push on the slide at floor level. I had some damage to my rig the first time when a couple of burly types pushed in the wrong place.
You will need something inside to keep it from sliding out on it's own if you plan to travel with no gear motor.
I cut some 3/4 inch pvc with crutch tips on each end to the right length to wedge in the top on each end.
2011 351RLTS Eagle, Mor/Ryde suspension & pin box
06 F350 Lariat PSD, SRW, LB, CC, EGR delete kit, 16K DrawTite hitch, Timbrens, TST TPMS
Can't find what you're looking on JOF? Try:Jayco Owners Forum Custom Google Search
"It's easier to fool people than to convince them that they have been fooled." - Mark Twain