How to Rebuild Lower Crank on a Pop Up Camper?

Pop-up campers are pretty cool because they’re simple, affordable, and give you a comfy camping spot without being too big. You can set them up in minutes, and they have a smart mechanical lifting system that smoothly raises and lowers the hardtop. The lower crank assembly is like the superhero, doing the heavy lifting to make it all work.

But over time, the crank parts go through a lot in different weather. Gears wear down, cables stretch, and things get misaligned. Lubricants dry out or get dirty. Eventually, the lifting system might not work as well. Fixing it might sound tricky, but with some guidance, patience, and basic tools, even DIYers with moderate skills can bring it back to life.

Here, you’ll get to know how to take apart and fix the gearbox in the pop-up camper’s lift system. It helps you identify where things are worn out and gives steps to make it work smoothly again. By following the advice, you can save money on expensive repairs and do it yourself. But it also helps you figure out when the problem is too big for a DIY fix. So, let’s get started with some wrenching!

How to Rebuild Lower Crank on a Pop Up Camper?

Proper Introduction to Lower Crank

Connecting the rotating lower crank handle to the overhead lifting cables, this gearbox allows high torque outputs from moderate human inputs. The operator turns an attached hand crank that spins several reductions of mated spur gears inside an oil-bath housing. In the final stage, a worm drive rotates a cable drum to wind or unwind the left and right lift cables in unison.

Robust gears comprise heat-treated alloys like hardened steel or surface-hardened brass. Gears feature shaved teeth to ensure precise mating with smooth, low-friction operation. The drum sits on an eccentric pivot so slight adjustments at rest optimize cable tension. Housings fill with SAE 80 or 90 gear oil to maintain lubrication. Two vertical drive cables attach to the drum at opposite flanges and run up to pulley assemblies under the upper bed and roof. Specialty stainless aircraft cables resist heavy loads and environmental corrosion. High tension coil springs connect to Pulleys delivering widening force against cable tension. Springs counteract roof weight while lifting and prevent sudden drops when lowering.

Diagnosing Common Lower Crank Issues

Several failure modes manifest from aging components suffering metal fatigue –

Noisy Operation: Gears slowly shed teeth from primitive lubricants inadequately protecting mating surfaces under high loads. Pitting corrosion also roughens up smooth contours. Such damage causes cog faces to grind rather than roll cleanly during rotation.

Resistance Lifting: Fraying steel cables stretch from cyclic stresses applied over years of raising/lowering cycles. Such elongation reduces the lifting force transferred to the upper pulleys.

Loose Hand Crank: Excess clearances between worn journal bushings and gearbox shafts create slop. Gears slide across shafts instead of positively engaging mates.

Tilting Roof: Differing left/right cable winds onto the drum applies imbalanced lifting forces. Springs may also have taken on different tensions over time.

Thoroughly inspect the gears, cables, and pulleys before assuming the crank needs to be rebuilt. Adjusting cables or tension springs may fix minor issues.

Necessary Tools and Materials

Gather key tools and supplies before disassembly –

Common hand tools (wrenches, screwdrivers, pliers)
Replacement hardware and lubricants
Digital camera – to record part configurations

Rebuild the kit with gears, cables, and bolts for your model
Shop manual with diagrams, specs, and procedures

Having organized parts, labeled bags, and a photographic reference helps greatly during reassembly.

Step-by-Step Disassemble Methodology

Rebuilding the temperamental gearbox starts with proper disassembly –

Step 1: Raise/lock the camper roof to access beneath without tension on lifting cables.

Step 2: Detach cables at both the upper pulley and lower drum ends. Tag each “Left” and “Right side for reinstallation. Coil up and set aside.

Step 3: Unbolt and detach the entire crank assembly from the trailer body. Take photos from all sides to reference component locations.

Step 4: Remove the outer crank handle and unthread the worm drive shaft. Extract keyway and thrust washers.

Step 5: Unbolt the gearcase covers detaching all spur gearshafts and related bushings as exposed. Note positions.

Step 6: Carefully split the housing to reveal geartrain components in a sequence of operations. This complex section benefits most from photos to assist in reassembly.

Step 7: Thoroughly clean all parts using solvents applied with brass wire brushes. Avoid damaging any precision finished surfaces. Flush clean with brake cleaner spray before inspection.

Assessing Damage and Planning Repairs

Closely inspect gears, shafts, and housing surfaces for problematic wear. Seek signs of –

Gear Pitting

Tiny surface cavities appear on tooth faces from metal fatigue and inadequate lubrication. Pitting prevents smooth rolling mesh.

Tooth Chipping

Whole gear teeth shear off under excessive peak loads from shock camming or abrupt lifting direction reversals.

Shaft Scoring

Heavy grooves inside bronze bushings cut into steel journals during rotation from insufficient lubricants.

Fatigue Cracking

Micro-fissures form at bolt holes, mounts, and along weldments in the housing or brackets from metal fatigue.

Based on wear inspection results, determine what components need replacement –

a) Chipped cog teeth must have new gears installed. Sand away burrs before fitting.

b) Tensile tests quantify cable integrity. Replace any under-spec.

c) Upgrade stretching bolts, worn pins, and defective pulley axles.

d) Carefully weld cracks then re-machine smooth.

Lubricating gears and pulley bushings reduce friction and wear. Follow the rebuild guide specs for oil baths or grease. Also, source repair parts like replacement gears, shafts, and bronze bushings. Seek help from dealerships or owner groups to identify obscure factory part numbers. Consider full overhaul kits.

Step-by-Step Rebuild Methodology

Now it’s time to rebuild your lower crank –

Step 1: Press keyway bushings firmly into the housing before inserting gearshafts by hand. Feel for smooth rotation without slop or binding.

Step 2: Gradually mesh gears in sequence using depth Micrometers to set face spacings exactly per spec. This ensures proper backlash between rotations.

Step 3: Mount the eccentric cable drum assembly back into the housing according to scribe marks. Center to provide tensioning adjustment range.

Step 4: Attach lift cables to the drum winding in opposite directions from flange to flange. Confirm no cable crosses over itself during winding.

Step 5: Bleed new gear oil into the housing until it runs out of the check port. This purges all trapped air inside.

Step 6: Test cycle cranking operations before mounting back on the trailer. Everything should turn smoothly and quietly before adding spring tension loads.

Watch for hesitation, odd noises, or binding sensations indicating issues. If problems arise, backtrack through assembly procedures to identify mistakes before proceeding. Carefully installed gears mesh smoothly while turning the crank takes steady, even pressure throughout the rotation.

Quick Post-Rebuild Maintenance Tips

Monthly Inspections – Check cable tension, lubrication, and pulley security.
Annual Cable Replacement – Cables endure tremendous cyclic strain.

3-Year Gear Inspection – Ensure gearbox components remain intact.
Storage Precautions – Always keep the roof slightly elevated with weight off cables.

Following factory guidelines for maintenance greatly extends the duty life of components between major rebuilds. But catching small issues early using thorough monthly walkarounds circumvents catastrophic failures needing extensive repairs down the road.

Wrapping It Up

DIY rebuilding the camper lift mechanism provides satisfying cost savings. However, lacking specialized tools and technical skills can produce subpar results or even worsen problems. Seeking professional assistance remains wise when proper cable tension exceeds your calibration tools, internal gearbox issues persist after the rebuild attempt, and structural cracks appear around crank mounts. With some careful disassembly, inspection, and part replacement, revive that aging lift system for years of more camping enjoyment. Just take things slow and leverage all available reference materials to ensure a reliable, quality rebuild.

Are aftermarket rebuild kits cheaper than OEM parts?

Many third-party suppliers offer rebuild components claiming OEM equivalency but at half the dealer price. However, machining, materials, and quality control often prove inferior. Gearbox components must endure extreme loads over 30+ year lifetimes. Saving a few dollars today by cutting corners leads to premature failure tomorrow. Stick with genuine factory parts despite higher initial outlay.

Can I convert my manual crank to an electric lift system?

Numerous companies offer powered camper lift replacements eliminating the manual crank effort. But simply bolting on an electric motor risks overloading the existing mechanicals never designed for augmented lift capacity. Added weight also stresses the roof structure. Consult an engineer to assess your entire lift system before attempting upgrades. Significant reinforcement may be required.

What lubricant works best for the gearbox assembly?

Opinions run the gamut from heavy grease to light oil. Thick lubricants adhere better to vertical surfaces but also attract gritty dirt over time. This eventually negates any lubrication benefit. Light-bodied synthetics like Mobil 1 flow readily between moving components while keeping debris suspended. Just ensure full drainage holes exist so excess oil escapes rather than pooling.