Toy hauler tongue jack landing gear

[CarterKraft]

Due to the type of hitch I use (pivot point projection) when I unhook I have to "tug" the stinger out of the hitch.
I usually spray the stinger with some really light lube like wd40 to allow it to release but sometimes it's harder to pull than normal.

Due to the length of the jack tube extension required to support the tall frame height of the trailer I have previously bent the jack tube...

There is also several times I have had to extend the tongue jack fully (18") and even put it on 10" stack of blocks to get the trailer level. With a 40' trailer length shit like that happens when the jack is at the tongue.

I bought a new jack to replace the old one that's just tired and I'd like to try and prevent bending the tube again and gain some stability and extra height.

This is the public onshape document my first assembly with motion etc.

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I'm not really looking for input on weather or not I need this more of does anyone see a simpler way to accomplish it, strength critiques etc.

I am thinking I might build this out of aluminum tube and sheet. Its 1/4" plate around the jack foot mount tube and 1" box tube for the a frame. The trunion mount will probably still be steel with everything in tension instead of compression, I don't have a good feeling of aluminum strengths.

I plan to keep this 3 hole jack mount so if I have to replace the jack on the road I can easily find a replacement Instead of having to modify a jack. It would be easy enought to modify the jack tube with trunions that just makes for custom pieces I might want to avoid.

Enough blabbing look at my pix...

 

[CarterKraft]

I didn't show it but the foot shows on the front of strut in the vertical position so I don't have to put anything in storage, everything is self contained.
There are holes at allow storage and 1.25" increases in height up to 5" increase if I need it. The swivel foot arrangement adds some additional height too, I didn't measure it just yet but it's probably around 3".

 

[SLOWPOKE693]

Trailer is going to move forward and backwards as you raise and lower the jack. If it's on tire blocks to level it side to side you may roll it off the blocks raising the front up to level the trailer if it needs to be extended close to full travel. How many inches backwards does the foot move from stored to full extension?

 

[SomeGuyFromOlympia]

I always upsize my jacks when I replace them
cranks easier, they usually come with a drop foot, and they dont bend

but they don't come with linkage

 

[Thatg9659]

Instead of those fixed jack support bars I would use two sleeved tubes that telescope, the outer with a welded nut and T bolt to lock them in place.

Set your jack, lock the bars no trailer moving while raising & lowering and no bent jack leg,

 

[BustedCrank]

Use an equipment trailer jack that is more beefy'er?
My trailer has a square tube jack on it, I've caught it on stuff and bent the trailer crossmember its bolted to, didn't hurt the jack one bit. And it's been hit more then a few times.

Something like this

 

[honEXduner]

Instead of those fixed jack support bars I would use two sleeved tubes that telescope, the outer with a welded nut and T bolt to lock them in place.

Set your jack, lock the bars no trailer moving while raising & lowering and no bent jack leg,

this - JT Strong Arms use this type of arrangement for fifth wheel landing gear, could probably do the same for this setup too

 

[arse_sidewards]

I can't see what you've got planned not being a massive upgrade over what you go. I say build it. Mostly because I'm gonna need the same shit for my trailer and I wanna copy whatever you do but with the benefit of hing sight.

Trailer isn't gonna move enough to matter. And IMO the fact that it does move will be more of a plus than a minus when you have to unhitch on any sort of slightly grade where it's hard to get no load on the hitch ball.

 

[rockota]

I can't see what you've got planned not being a massive upgrade over what you go. I say build it. Mostly because I'm gonna need the same shit for my trailer and I wanna copy whatever you do but with the benefit of hing sight.

Trailer isn't gonna move enough to matter. And IMO the fact that it does move will be more of a plus than a minus when you have to unhitch on any sort of slightly grade where it's hard to get no load on the hitch ball.

Trailer looks like it’s going to need to move 3-4”. That’s not going to work if it’s correctly blocked.

 

[arse_sidewards]

Trailer looks like it’s going to need to move 3-4”.

Not all of that movement is going into forward movement of the trailer, frame is gonna be moving up. Need about an inch to get the coupler off the ball anyway. It'll be fine....

That’s not going to work if it’s correctly blocked.

Block behind the trailer. Jack pressure on the ground gets the front of the trailer. Problem solved.

Yeah it'll be a bitch if pointed downhill but everything but a pintle is.

 

[SLOWPOKE693]

Not all of that movement is going into forward movement of the trailer, frame is gonna be moving up. Need about an inch to get the coupler off the ball anyway. It'll be fine....

Block behind the trailer. Jack pressure on the ground gets the front of the trailer. Problem solved.

Yeah it'll be a bitch if pointed downhill but everything but a pintle is.

Stick your floor jack in the dirt, jack up your Subaru by the crossmember closest to the oil pan and report back about it not moving enough to matter......

 

[TrailTamer]

I always upsize my jacks when I replace them
cranks easier, they usually come with a drop foot, and they dont bend

but they don't come with linkage

That’s what I will do. They can be made easy to replace if you use square U-bolts. Linked trailer jack

5000 lb. Capacity Drop Leg Trailer Jack

Amazing deals on this 5000Lb Drop Leg Trailer Jack at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

 

[CarterKraft]

Trailer is going to move forward and backwards as you raise and lower the jack. If it's on tire blocks to level it side to side you may roll it off the blocks raising the front up to level the trailer if it needs to be extended close to full travel. How many inches backwards does the foot move from stored to full extension?

You're not wrong, I'll figure out how much it will actually move from ground contact to full lift.

Trailer looks like it’s going to need to move 3-4”. That’s not going to work if it’s correctly blocked.

Possible,
But the deal is with this style hitch there is no ball to go up and over. The stinger just pulls straight out of the hitch. It only needs to be jacked up enough to remove the weight off the truck.

I can see this forward backward movement being a problem though in the right context, I dismissed it when drawing it up I figured the foot would slide before it pushed the trailer.
I was going to radius the edges of the foot to help.

 

[CarterKraft]

Instead of those fixed jack support bars I would use two sleeved tubes that telescope, the outer with a welded nut and T bolt to lock them in place.

Set your jack, lock the bars no trailer moving while raising & lowering and no bent jack leg,

That's not a bad idea actually but I'd probably use pins and drill the sleeved tubes to get positive stops at certain lengths.

Let me plot the avg distance from unhitched to 6-10" lift and I'll determine if that looks like a problem.

This project is 75% hone CAD skills and 25% necessity

 

[rockota]

Curious why not just a larger Jack as suggested?

Or is this post surgery, pain med induced “I think I can make this more complicated if I try harder” design work??

 

[CarterKraft]

Use an equipment trailer jack that is more beefy'er?
My trailer has a square tube jack on it, I've caught it on stuff and bent the trailer crossmember its bolted to, didn't hurt the jack one bit. And it's been hit more then a few times.

Something like this

I have some 4" tube electric jacks off a motorhome leveling system but they have obsolete motors and are really heavy.

I blew off using one of these jacks due to those issues but it's possible I could retrofit a more commonly available motor assembly to the square jack. It would be very strong comparatively.

The original inspiration for this was the
u-haul trailer jack leg assembly. I tried to find some pix of Jane the other day but Ai has royally fucked my ability to goog search for shit anymore.

 

[CarterKraft]

Curious why not just a larger Jack as suggested?

Or is this post surgery, pain med induced “I think I can make this more complicated if I try harder” design work??

You guys don't know me personally but this is kind of what I do...

The more simply complicated the project gets the happier I am.
I guess it's like designing an airplane gismo, max strength to weight. It's fun to design, fun to build and really rewarding to use.

 

[CarterKraft]

This design cuts the jack capacity in half, that won't work I need the full capacity of the 3500 lb rating because when the rear leveling jacks are down there is more to gue weight than when the trailer can pivot on the axles.
I was going to do this with a hydraulic tongue jack cylinder and a 12v Parker hydraulic unit I have. But theres no reduncy with that system, if it fails to lift I'm fucked.

 

[CarterKraft]

Here's the lineup

 

[CarterKraft]

The two square jacks have legit ball screws and brakes on the shafts, really complicated, discontinued and currently broken...

Looking at this now I bet I can cut the round tube jack up weld the round pipe to the top of the square jack and weld the ball nut to the leg, I don't gain any capacity that way but I get a easily replaced motor and a hell for stout jack tube/leg.

 

[arse_sidewards]

You're not wrong, I'll figure out how much it will actually move from ground contact to full lift.

I'm gonna go out on a limb and guess that it's gonna be far less than a floor jack arm would move in the same distance. \

Stick your floor jack in the dirt, jack up your Subaru by the crossmember closest to the oil pan and report back about it not moving enough to matter......

There's a difference between jacking up a car with a 14" jack arm and jacking up a trailer with a 36" arm

You'd think I wouldn't have to say that on IBB....

But theres no reduncy with that system, if it fails to lift I'm fucked.

Weld a loop to the side of the trailer frame to stick your high lift jack in.

 

[CarterKraft]

I'm gonna go out on a limb and guess that it's gonna be far less than a floor jack arm would move in the same distance. \


There's a difference between jacking up a car with a 14" jack arm and jacking up a trailer with a 36" arm

You'd think I wouldn't have to say that on IBB....


Weld a loop to the side of the trailer frame to stick your high lift jack in.

Well while I was out there fuckin around with this stuff I started feeling shitty and a 101.8 temp was measured and I shut it down for the day, id assume I have the flu? Etc.

Hopefully I feel better tomorrow and I'll get on the laptop.
The trailer sits high, the jack doesn't hit the ground for a long time...

 

[arse_sidewards]

That's a real cluster fuck you got there.

 

[OHV Wildcat]

That setup totally needs some more arms going everywhere!

 

[SLOWPOKE693]

That setup totally needs some more arms going everywhere!

That's what I was thinking!

 

[YotaAtieToo]

Rv guys are funny

Omg, I have a 7500lb trailer behind my dually. Better get that $3k dollar octopus hitch

Mean while contractors pull 14-26k lb off the bumper every day, zero octopus



For real though, I always liked the uhaul design. I'd do something like that with a much larger jack.

 

[aczlan]

This design cuts the jack capacity in half, that won't work I need the full capacity of the 3500 lb rating because when the rear leveling jacks are down there is more to gue weight than when the trailer can pivot on the axles.
I was going to do this with a hydraulic tongue jack cylinder and a 12v Parker hydraulic unit I have. But theres no reduncy with that system, if it fails to lift I'm fucked.

What if you move the pivot all the way down to the "foot" (blue circle), then you don't lose any capacity?

More or less what you were thinking of with the legs, but make the jack pivot at the bottom and the mounting point instead of a pair of extending braces.

Aaron Z

 

[arse_sidewards]

What if you move the pivot all the way down to the "foot" (blue circle), then you don't lose any capacity?

Which is exactly what he did but better and then everyone called it stupid over a little bit of trailer movement that's likely a non-issue for him since it's not for Uhaul.

 

[aczlan]

Which is exactly what he did but better and then everyone called it stupid over a little bit of trailer movement that's likely a non-issue for him since it's not for Uhaul.

Ah, I missed the pivot in the pictures and the adjusting discussion was more to do with a non-swiveling jack.
Not sure why you would want any adjustment once the link lengths are set.

If you use a drop leg jack, then springs on the "arms" it should pull up easily and reduce the working distance needed for the jack.

Aaron Z

 

[CarterKraft]

Like arse said due to the tongue and all its accessories the linkage had to be reversed from the u-haul style.

The extra holes were a after thought but there are times when maximum height is needed so any additional height is welcome.

I'm still pondering converting the 4" tubed jack to the new screw/motor and mounting it at the rear of the tongue under the fiberglass cap, behind the propane tanks.
It would be a increased moment arm and so it might not be strong enough...

This "flu" has kicked my ass pretty good so I'm not doing shit anytime soon.