Happijac 4500 - How to lubricate the Happijac 

Thanks for the video lesson! It made my job a lot easier. Took me about 45 minutes to remove, disassemble, clean, lubricate and reassemble and remount on the camper. Couple of notes. I don't know how old or new your jacks are but mine were slightly different than yours. Primary difference was that on the shaft that has the vertical plane gear (the one attached to the short shaft which is turned by the manual handle) the attachment was by snap ring rather than by cotter pin. Second difference is that the horizonal gear (the one that actually turns the main jack screw was not attached in any way to the shaft. All I had to do was hit it a couple of times and the main screw shaft just fell out. There was a small keeper pin (1/8 x 3/4) which passes through the upper end of the jack screw shaft and fits in a keyway in the horizonal gear to anchor it to the jack screw shaft (holding it rigid to the jackscrew so that the gear actually turns the jackscrew.) All the rest was the same. I want to check with Happijack to see if they offer a rebuild kit with a few items that get worn out over time,

"your not recording this are you" lol, priceless. Thanks for the FYI and the good humour.

Thank you for the video! I don’t even want to begin thinking about how much money this saved me!

“It’s real easy to take apart”. Yes, that’s true. Putting the jack back together again can be a real challenge. Slipping the pin back in is tricky, as is replacing the gear that goes on top of it. By the 4th one, I completed the entire process in 60 minutes. (My screws needed wire brushing and a good wipe down.) Thanks for posting! Although I got the pdfs from Happijac, your video was much better. Saved me @ $2,000 over buying new jacks.

Thanks for that, I’m just about to tackle mine. seeing what is in there before I pull it apart is a great help. 👍👍👍

Thanks so much for this; I'm getting ready to refurbish my Happijacs and this helped me get familiar with the internals of these things.

My 2006 Bigfoot has Happijaccs, they worked great for about six years then all of a sudden with lots of moisture over the last few years they’ve become weaker, one of them won’t even start to lift the camper, took it apart and the motor was full of moisture and grit, cleaned it up and it works at about 50% strength. I removed the gears and threaded rod, greased it and put back together. One thing I was thinking on doing was to install a grease zerks on all of them at the bottom end where the threaded rod goes through the large plastic nut on the inside. Great video.

Thank you for the great how to. I used your video to lubricate all 4 of my powered happijacs this past weekend. (4500 and 4150) I would like to note that when removing the plug for the directional block if you use 2 screw drivers and pry them out they don't chip apart. Also when you put them back in I smacked one too hard and it broke. I will have to drill the plug out and replace it the next time I perform maintenance on the jacks. All in all a great video that was very helpful, thanks!

Thanks, great video. I had to make new hex sockets as mine had all snapped. I used 3/8 drive 1/2 inch deep sockets 6 point. I had to skim a 1mm off the outside the cut the socket then weld them on. Thank you your video saved me $2500 aud in replacing 4 jacks

Thanks for taking the time to make this video.

Thank you so much for this video, it was a tremendous help.

That’s great! Thanks for the video!! Helped a lot

Thanks for posting this... very helpful...

Great video on how to take jack apart, however oil will run down the screw bolt that raises or lowers jack all you have to do is after you take top cap or electric motor off is pour a little oil on top of jack where the gears are then run jack up and down with a 1/2 inch Allen socket and drill and oil will run down around the screw and you will know this because oil will come out of bottom of jack. It is very hard to try and get enough oil through little hole where you insert handle to raise and lower jack. Been doing this for years and it works great for keeping screw lubed up.

Thank you very much for your video help me to fix my problem

Thanks jerry ur description is correct I said cotter pin but it was the c clip like u said

Very helpful, thanks. I got mine disassembled to the point where the outer tube slips off the inner one, but mine is stuck hard. I cranked it out as far as I could, repeated the disassembly, and still it's stuck. Next thing to try... chain one end to a tree, the other to my truck, and try yanking it apart?

Great video - thanks! I'm about to try this on my own jacks - they are brand new, on a brand new camper, but they are making sounds like I've never heard before on previous campers. Hope this is the soluition!

Your giving out incorrect information, Because I just did it and I used Lucas oil stabilizer the Dino not synthetic and it’s real thick and I pulled top off and poured it in and about 2-3 days was a pool of oil on the floor so I ran that Jack up and down and it worked outstanding so I got four rubber plugs and drilled one hole in each cover to be able to grease them up and real easy , and you do not have to tear it apart like the owner at Bigfoot said. Not downing you but just wanted to get the word out that it works great .

You pull the top off happy jacks and fill it half up with Lucas oil stabilizer and every time you run your Jack up and down it will slowly run down the large screw in you Jack if the oil is to thin it will ru quicker and drip on ground but it does work just like they told you .

Thank you again Jordan now that I have just finished doing all my jacks. I would like to make a recommendation. That stupid little plastic button you were having so much trouble with, my first one ended up looking like yours. :( What worked good was drilling a small hole in the middle and screwing in a wood screw so you can hook the claw hammer on it and just pop it out. Remember to fill the inside of the button with silicon or caulk or gum so the water can’t get in. Now if I can rant a little bit. You’d think for the price of these damn things they’d come up with a better system than that plastic button that I’m sure usually gets broken. And for the price I’m sure they could have used galvanized tube so you didn’t have to worry about them rusting. There I’m done. On the upside they don’t leak hydraulic oil.

I just raise the camper up drill a small hole and used a oil can and squirted oil in the hole. Bing Bangor done. 👍

"And after that, the screw jack just comes right apart."....after I beat on it with a 1x1 for a few minutes! Yours came apart a lot easier than mine. But I dont think this has been serviced since 2005. Gears are badly worn.

The dry spray granite lube is really good because it does not collect dirt and dust on your drive screw .

one of mine is going slow (i have the power ones) I have been putting it off for a while because I figured it would be an all day thing and involve more than a bit of profanity. Now I should be able to do all 4 in a couple of hours

The Lucas oil stabilizer is as think as honey and will last for years just don’t fill over half way or it my sip out the lever hole or the white plug hole on the sides hope this helps .

Where do you get the first plastic plug that broke?

And you can pour oil inside gear box and run it up and down oil will run out the bottom of leg so a thick lube like Lucas oil stabilizer Dino type not synthetic it’s too thin Dino is like honey. Hope this helps some one .

I put Lucas pure suit hives the first and ran it back forth and next mournig I had oil on the floor so that when I went to the regular Lucas oil stabilizer and it does not leak out like that because the regular Lucas is a lot thicker hope this helps

Great video. I did all that disassembly and lubed up the screw with the white lithium grease but I still get a bad whine and resistance under load only. Is there something to replace or modify in the worm gear area that might resolve this? - Maybe a washer missing under one of the gears? Does the lower gear ride on the pin? any ideas on how to get rid of this whine and resistance under load?

You do not have take the apart to lube your screw and lower gears in leg . Just pull the whole top motor and all and log end the and put enough Lucas oil stabilizer and stay below the leve and the plug on a olde Jack I had I put to much in. But the does leak threw and down on the main screw.

My front right jack makes a ratcheting sound like a clutch on a screw gun, it seems to make that noise if the weight is uneven .

Where is the black plastic square piece that has large hole in it that 2 different shelves on it. When I took mine apart it all fell out in like 10-12 pieces so that’s what trying to see on your video but no show and I need that part and I have only took one apart so could you send a picture of that part or where to get one my model number for my Jack is model number is 4150 ?

Don't hammer away at plastic insert. Once motor is removed you can insert a screwdriver into slots in the lever mechanism and gently pry sideways. This will easily pop out the insert being destroyed in this video. I have yet to see a replacement part on line to repair type of damage inflicted.

That first white plug will break off 99% of the time just knife clean and off the plug off and leave rest of plug in and just find a screw with big enough head to go over metal leg so it doesn’t pull threw and stainless screw won’t rest. If you order that part they don’t just sell the pin. They will sell the pin the lever and locking part on inside for 40 bucks plus shipping.

What size hex fits into jack?

Has anyone had a 4150 apart, not sure about the reassembly.

What your telling people on how to lube your happy jacks is wrong . I found 4 rubber plugs and I drilled a hole on the top of each gear box and put a good squeeze in each box and put a bucks under each leg and the next day there was a little pool of oil in the bucket and with the camper supported I ran all my jacks up and down and after running the up and down they quite and I did not have to reset the jacks not one time with them all 4 motors.

For new legs with gears is about 1400 a piece ouch .

Taking g it apart is one thing, but why didn' you show it being put back together? Way more important to see.

I think I'd rather just use a spray lub and not go to so much trouble.

This is wrong information you can take plastic top off gear box and I put Lucas oil stablizer and I pour it in the top gear box and runs down the screw of a happy Jack. So what this guy says is wrong you can lube them from the top and it will run down screw out the bottom so this guy may believe this but he’s wrong so remove the plastic cover and square Lucas oil stablizer in top put paper plate under leg and there will be oil on the paper plate and run it up and down and it works slick as can be . You don’t have to do what this guy says happy Jack told me it works and it does . I drilled a hole in cover and put lube in gear box and you good to go !!😊