Landing gear/jack problem

road2002runner wrote:
My thoughts lean to - - only one motor driving two legs might cause a bind - If that is your situation. I like the idea of lube. I run the legs to FULL hight - block the frame - then do the LUBE JOB. and then run the legs up and down several times - - with NO weight on the legs. You guys have GOOD IDEAS. Once a year might be enough. I have ALSO BROKEN the main lower/raise screw - may have been due to poor material I WAS able to REDRILL the shaft and install a new bolt.
NOW - any NEW trailer ( have had 4) BEFORE I use the unit I re-drill the screw holes and use a Grade 8 hardened bolts in US and NOT metric size to replace, !/4/ inch as I recall I also use washers to take up ANY slack in the unit - Like who ever heard of a square tube on a round shaft, the spacer washers take up ANY SLACK - NOW when I hit the Raise/Lower button it engages RIGHT AWAY - with NO DELAY of the round shaft taking up slack on the square shaft.
I hope this sounds what I mean.
Easy peasy - about 1 hr work - cured forever.

One of the main reasons for using a low-grade bolt in that type of application (2 jacks, one motor) is that the bolt acts as a shear pin in case the "off side" jack binds up. It's =designed= to break to prevent further damage (hopefully). Same reason for using a square tube on a round shaft. If the shear breaks, then the motor can continue to turn without breaking =more= stuff. I can certainly tell you that I love having 2 motors on my KZ, with 4-point leveling. It's actually =much= faster raising and lowering. Knowing what I know now, I'd've changed out the jacks on my old Komfort years ago.

Lyle

I had an issue with the inner leg scrapping against the seam weld on the outer sleeve.

My thoughts lean to - - only one motor driving two legs might cause a bind - If that is your situation. I like the idea of lube. I run the legs to FULL hight - block the frame - then do the LUBE JOB. and then run the legs up and down several times - - with NO weight on the legs. You guys have GOOD IDEAS. Once a year might be enough. I have ALSO BROKEN the main lower/raise screw - may have been due to poor material I WAS able to REDRILL the shaft and install a new bolt.
NOW - any NEW trailer ( have had 4) BEFORE I use the unit I re-drill the screw holes and use a Grade 8 hardened bolts in US and NOT metric size to replace, !/4/ inch as I recall I also use washers to take up ANY slack in the unit - Like who ever heard of a square tube on a round shaft, the spacer washers take up ANY SLACK - NOW when I hit the Raise/Lower button it engages RIGHT AWAY - with NO DELAY of the round shaft taking up slack on the square shaft.
I hope this sounds what I mean.
Easy peasy - about 1 hr work - cured forever.

Check out a Youtube guy called Love your RV, he has a video about replacing and greasing the jack screws. Sounds like the jack screw inside is going bad. These can't be replaced. You'll have to replace the entire unit. One side only not both sides. Considering the one side is failing the other may follow soon so it may be wise to replace both.

blofgren wrote:
bpounds, thank you for your excellent, detailed post. I have looked at my landing gear in the past and was unsure of where to drill the holes but it is much clearer now.

I haven`t noticed any noise out of mine yet but will lube them to hopefully prevent future problems.

No problem. I didn't come up with the idea. Probably got it right here on RV.net.

bpounds, thank you for your excellent, detailed post. I have looked at my landing gear in the past and was unsure of where to drill the holes but it is much clearer now.

I haven`t noticed any noise out of mine yet but will lube them to hopefully prevent future problems.

Follow up on repair: used the pipe insulation to apply grease to worm gear and everything works/sounds fine. Thanks for all the suggestions.

While the pipe insulation works, I feel bpounds idea of drilling a hole in the square tubing might be a better solution. Much more convenient and less messy. I guess it would depend on if oil would work as well as grease. My opinion would be that it would if applied a couple of time a year.

The other solution of using clear tubing with a zerk fitting attached to the end of it seems like the better solution if one wants to use grease.

bpounds wrote:
Just to be clear, when the possibility of the leg being bent is mentioned, we are talking about one or more of the 3 square tubes that make up the telescoping leg. Not the threaded jack screw. My personal preference is to not lube between the surfaces of the square tubes. They are not a friction fit, they work just fine dry, and I don't want the mess of excess grease running down the legs.

Here is what I did to lube the jack screws. I extended the legs a good amount, to make sure all of the square tube and follower nut were well down in the leg. I did this with the weight of the trailer still on the landing gear. Then I drilled a hole in the side of each leg, just above the upper clamping saddle. The legs being extended meant that I would have access to the upper portion of the jack screw through these drilled holes. Then I used motorcycle chain and cable spray lube, with the spray straw attached, and lubed the jack screw liberally, enough that the lube would run down the jack screw. Obviously I was only lubing the upper portion of the screw. Once the lube was applied, I ran the legs back up all the way. That brought the follower nut up into the lubricated portion of the screw, and transferred the lube into the nut. Back and forth a couplethree times, and you have effectively transferred lube along the jack screws. I sprayed liberally enough to be sure that some lube would get around the outer edges of the follower nut where it rides along the square tube. Pics below show about where the holes were drilled. You can see the inner leg through the holes because the trailer has been lowered back down to the level position.

The convenience of this is that you don't have to disassemble anything, and the holes are there for future regular maintenance. This made a remarkable difference in how easily the gear lifted my trailer, and I have not had to do it again so far. My guess is they don't do much if any lubrication at the factory, so the first time you lube it you will see a large improvement. This should be on everyone's prep list for their brand new trailer, in my opinion.

I have to say though, I also really like the idea of using pipe insulation and getting some lube directly on the lower end of the screw, as well as some heavier lube than the chain spray. I might give that a try this winter.

Chain and cable spray is good stuff, because it is designed to flow easily out of the can, then it penetrates (the chain pins and cable sheath by design), and then it dries quickly and clings to surfaces. It has to cling well at the rotating speed of a motorcycle chain. Once applied it dries and does not run out the bottom of your telescoping leg. You can see I also used it to lubricate the bushings on the gear box and the bevel gear shafts. I used regular moly based wheel bearing grease on the bevel gears themselves. The high pressure tooth surfaces of the gears need a heavier grease.

If he has overextended it ,then he could of messed up the worm gear ,and then messed up the nut that it goes thru, and no amount of lube is going to fix anything.

I messed mine up, by leaving the braces that I copied that Steadyfast sells and forgot to release them. Forcing the landing gear, didn't notice until it got to the point where there was no more give, , and it tweaked the worm gear threads. Its a wonder I didn't burn up the motor, I explained in my other post what I did to fix it, although they are not meant to be able to be taken apart like I did .

dryfly wrote:
Bpounds:

Excellent post. Makes sense what you are saying about where a bend would take place, and assures me I'm not dealing with that issue now. My jack legs look fine so I'm more certain my problem is with the UN-greased screw.

I like what you did with the drilling of holes, but right now think I'll start with the grease on the pipe insulation. My jack is in such a bind that the first thing I have to do is get the weight off it before I try anything.

After that, I'm hoping I can turn the screw shaft enough to work the grease up into the nut. If not, I'll drill and let the oil run down into the nut.

I'm feeling a lot better about this project and will tackle it in the next couple of days. Thanks for posting the pictures.

Its most likely the worm gear, I had the same issue, and found where the threads on the long worm gear was mushroomed just slightly not allowing it to turn on the nut freely . I took to a friend at a machine shop ,and they chased the worm gear, and all was well .

They are really not made to take apart although I did, its tough to explain how ,but I was able.
At that point with the worm gear, most would just have to just replace the whole unit. Mine is not made to be able to actually replace that long worm gear. Some may , but mine is not.

No amount of grease is going to fix it if the worm gear is messed up some .

My jacks were binding and breaking the sacrificial bolt on the cross shaft as well as tripping the breaker. I used bpounds' method of drilling holes in the tubes right above the top bracket. If you do that, be careful not to push too hard on the drill or you'll hit the screw with the drill bit. Start with a small hole and then bore it out with a larger bit. I used spray lithium grease inserting the straw into the hole and directing it up and down as I sprayed. Then, with the trailer hitched to the truck, I ran the legs up and down several times to spread the lube as best I could.

This made a huge difference in the operation of my landing gear. That said, the pipe insulation method on the video has me intrigued. I believe I will add this as a step next time I lube the landing gear.