Happijac - Loading and Unloading Your Camper.
With electric jacks loading and unloading your camper can be done in a matter of minutes. However if you don’t observe a few simple rules, it can turn into a nightmare. Large campers can weigh upwards of 1500kg so care should be taken.
The legs on campers are very strong vertically - lifting straight up and down when the camper and the ground are level. However their lateral or sideways strength is limited so care has to be taken when the ground is not level.
If you don’t have level ground then it is best to have your vehicle facing uphill before unloading. Extremely sloped ground should be avoided.
Using footpads is recommended. I use treated pine sleepers cut into 1 foot lengths. Place one under each leg before commencing to raise the camper. Lower the legs till the first leg reaches the footpad. You will then be able to see the difference between the highest and lowest leg - the leg still furthest from the footpad. I often put a second footpad below the lowest leg. Drop the remaining legs individually until they are all in contact with the footpads. Carefully raise each leg slowly till the camper is level - most important.
You should use a spirit level to check the level. The spirit level should be placed on the floor inside the camper door as the inside floor is usually the most level part of the camper.
You may often find that the camper will separate from the truck on the lowest side first. Keep the camper as level as possible, and continue to raise it until it has clearance from the truck at all points. Make sure you have enough clearance to compensate for any uneven ground under the truck as you drive it out.
Always lift the front of the camper first so that it is approximately 4” or 10cm higher than the back. Try to keep the front higher throughout the lifting process, remembering that the front jacks carry the most weight and often this causes the back to lift faster.
When unloading, be careful when the legs start taking the weight off the truck. If it is not level the truck will move a small amount as the weight is lifted.
Similarly when loading the camper, as the weight goes on to the truck the legs may kick out a bit as the load comes off them, especially on uneven ground. Keeping it level is so important.
Likewise when loading the camper on uneven ground, keep the camper level at all times. It is more important to have the camper as level as possible, even if it is not initially parallel with the truck tray.
Foot pads should only be used to stop the camper legs sinking into the ground and to build the low side up by around 4” to 6” - 100mm to 150mm. We use treated pine sleepers cut into squares of about 30cm.
You should read and thoroughly understand the jack manufacturers manual and ensure that you maintain the jacks in good working order at all times. That is of course if you have the manual. If not see below.
If you are loading or unloading and the jacks or the motors start making any unusual noises then you should check that the camper is level (slightly higher at the front). This can also happen if the legs are not straight or properly aligned.
Never over extend the jacks. They have marks to indicate their maximum extent. If you exceed this they may die, and you have to pay for the funeral. Likewise never retract them fully, usually an inch from the end is good. Same funeral costs.
Jacks will often extend or retract at different rates. This would be due to the load on each jack, with the lighter load going faster. Just keep an eye on them and adjust so that they are even.
Never be afraid to phone and ask if you are not sure. It could save you big dollars and save you from ruining your trip. It’s not as if you are asking for directions!
Understanding the new model Happijac Legs, Motors and Remote Control Systems
A few years ago Happijac changed all the models of their camper jack systems. While the reasons are not fully clear it has caused some angst among owners of campers with the older model parts. The new models are stronger and more reliable and the backup support and service is excellent. Happijac remain the number one supplier of camper jacks.
This article is to give a brief summary of the new parts and how they interact with the older models. While most parts are interchangeable care must be taken or you can damage your legs, or jacks as they are known in USA.
The Legs or Jacks
Happijac now make only two models of legs - the 4820 and the 4220. The 4820 is 3’ or 75mm longer than the 4220 and has a greater load bearing capacity. This model replaces the 4800 which was the same length. The additional length is handy in Australia where we load campers onto trays and not into the tubs of utes or pickups. Being the same cost I would recommend anyone buying a full set of legs to get the 4820’s. The 4220 effectively replaces all the other Happijac models, including the 4150, 4160, 4500, 4560 and 4600. The fitment of the 4820 and the 4220 is the same as the previous models. They fit the existing brackets and the motors, both new and old models, fit in the same way as the old model legs. There is one difference in that the 4820 and the 4220 are fitted with a rubber bushing to prevent any sudden stop from overwinding the legs up or down. More on that in the new motor section.
The New Motors
The old style motors (model 182515) had a built in clutch system designed to prevent the motor from destroying the gears if the motor was overwound. Should you reach the end of the jack you would hear a clicking noise, which was the clutch saving the leg from extinction. In theory this was a good idea but in practice the clutch would sometimes engage randomly, possibly due to corrosion in the leg. A lot of the old style motors had to be replaced. While I am not sure why I suspect it was from the legs jamming or binding, the clutch failing or just old age and possibly the motors not being up for the job.
The old motors were replaced with new Vertical Orientation Clutchless Current Sensing (CCS) Motors. These new motors are quieter and more reliable. Obviously they have no clutch which has been replaced by the Current Sensing System which detects that the leg is fully wound and shuts the motor down to prevent damage. This is why they have put a rubber bushing in the new legs to prevent the leg from coming to an instant dead stop and give it the split second it needs to shut off. For this system to work it requires a CCS Control Board and Remote Control unit.
While the old Control Board and Remote will operate these motors, when the legs are fully wound in or out there is no clutch and nothing to tell the motor to stop. So if you are not watching and continue winding, the motor might do serious damage to the drive mechanism in the leg. To be safe, if you are putting new motors on old legs, you should also replace the Control Board and Remote unit. Even if you are only putting one new motor on you should have the new Control Board/Remote. By doing this the new motor that you have installed will stop using the CCS system and the other motors will stop using the clutch and/or the CCS.
While the new Vertical Orientation CCS motors fit exactly the same way as the old motors, there are a couple of problems. The new motors are slightly larger in circumference. So if your legs were fitted flush against the side of your camper then you will have to fit new brackets to bring the leg out a small amount. The new brackets are readily available and not that expensive.
The second problem with the Vertical Orientation motors occurs when they have been fitted under the bedroom or cabover of the camper. There is often not enough room to fit the new motors without moving the mounting bracket for that leg..
Old Motors.
When the new models of legs, motors and remotes was introduced, Happijac ceased production of the old models. Eventually they ran out of stock of the old models and then people became a bit upset when the could not get a replacement motor. Fortunately they have now made a supply of the old model motors, which are reportedly an improvement on the original model. How long these motors remain available we don’t know. We have a supply of them now at Truck Campers Australia, for which my customers are most grateful for.
The New Control Board and Remote Control Units
These new units are specifically designed to work with the new motors and the new legs, using the Clutchless Current Sensing System to protect the motors from overwinding and possible damage. However they will also operate the old style motors quite safely as far as I am aware, as the the old motors clutch system will still work.
HapPijac Jack or Leg Maintenance
Step One
Check all mounting screws and other hardware frequently for tightness and proper jack alignment .
While checking the mounting hardware is secure is easy, not so checking the alignment of the jacks. This is best done with the camper mounted on the truck on level ground. Extend the jacks till they nearly reach the ground. Measure the distance between the top of the jacks and then the bottom of the jacks. It should be the same, or very close. You may need to alter the bracket or fit a washer or two to the bolts where the jack is mounted. Remember a small adjustment at the top will make a large adjustment at the bottom.
If you have a motor making noise while lifting and the camper is level (a bit higher at the front) then there is every chance you have a misaligned leg or jack. This could blow the fuse in the control board or worse kill the motor.
Step Two
Clean mounting brackets and both inner and outer tubes of jack and wax the tubes with Carnauba wax every 6 months. You can only wax the outside of each steel tube. Cleaning the inside of the outer tube is near impossible.
It is important to check for any corrosion on the inner tube. If it is evident, it must be removed. I have done this with fine grade wet and dry paper, being careful not remove any more of the galvanising than is already corroded and not to remove the height indicators from the jack. Once smooth it should be waxed and checked regularly.
Corrosion if left unattended can cause the legs to seize and then the motors will fail, which is costly.
Never apply grease or oil to the tubes. It collects dust and jams the operation of the legs and is bad in the long term.
Step Three
Fully extend jacks to red safety line once each year. This redistributes lubrication evenly on the screw shaft. Remove top cap and re-grease gears (if needed) with white lithium grease. Lightly oil bearings
This sounds simple enough but not always so. There are only two screws to be removed to take the motor off but you must be careful not lose any of the springs, washers or other parts that will surely jump out when you are not looking. They must be replaced in the correct order . Adding some lithium grease to the gears etc is easy. If you have to add machine oil to the screw shaft underneath is harder is there is no oil hole in the crank.
Again, only use lithium grease and machine oil (not WD40 which is a good multi purpose cleaner and lubricator but not a good long term lubricant).
Step Four
After periods of non-use, or anytime the jack seems to labor more than usual, place a few drops of light machine oil into the oil hole in the crank socket, then run the jack to distribute the oil.
Most of the newer jacks have a hole inside where the manual crank is inserted. You will find it on one of the flat hexagonal surfaces inside. Rotate the crank until the hole is facing down so the oil will run out. Older models do not always have this hole so you have to get the oil in by removing the cap (manual wind jacks) or the motor for auto wind jacks.