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Atlas IV Single-Acting Hydraulic Trailer Jack w/ 48" Dump Kit - 10,000 lbs - Bolt On
Stillwell

Atlas IV Single-Acting Hydraulic Trailer Jack w/ 48" Dump Kit - 10,000 lbs - Bolt On

Part Number: ST77VR
$784.25
Trailer Jack
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Upgrade your power-up/gravity-down dump trailer from manual cranking with a 10,000-lb Atlas IV jack. Hydraulic pressure extends the jack, compressed air retracts it, and the 48" kit includes the valve, hoses, and fittings. Great Prices for the best trailer jack from Stillwell. Atlas IV Single-Acting Hydraulic Trailer Jack w/ 48" Dump Kit - 10,000 lbs - Bolt On part number ST77VR can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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Stillwell Trailer Jack - ST77VR

  • Dump Trailer
  • Enclosed Trailer
  • 5th Wheel Trailer
  • Gooseneck Trailer
  • 9001 - 10000 lbs
  • Hydraulic Jack
  • Bolt-On
  • Side-Mount Jacks
  • With Rectangle Foot
  • 26 Inch Lift
  • Stillwell

Upgrade your power-up/gravity-down dump trailer from manual cranking with a 10,000-lb Atlas IV jack. Hydraulic pressure extends the jack, compressed air retracts it, and the 48" kit includes the valve, hoses, and fittings.


Highlights

  • Upgrade Your Dump Trailer to Hydraulic: 10,000-lb capacity and 26" lift replace repeated manual cranking.
  • Built for Power-Up/Gravity-Down Systems: Shares the hydraulic pump already powering your dump bed.
  • Compressed-Air Retraction: Hydraulic pressure extends the jack, while the NeXgen adapter lets you add air to maintain the pressure needed to retract it.
  • Connection Kit Included: Selector valve, two hoses, and fittings tie the jack into your trailer's hydraulic system.
  • Plan Your Hose Routing: Check pump, valve, and jack locations against the included hose lengths before installation.
  • Bolt-On Universal Mounting Bracket: Eight-hole pattern gives you more flexibility when matching the jack to your trailer frame.

Made in USA

Features to Know About

Put Your Dump Trailer's Hydraulics to Work

If you're still cranking a heavy manual jack even though your dump trailer already has hydraulic power, this Atlas IV kit lets you put that system to work at the tongue too. The jack gives you 10,000 lbs of lifting capacity and 26" of lift for easier hitching and unhitching when you're dealing with a heavy work trailer.

Hydraulic Power Out, Compressed Air Back In

This single-acting Atlas is designed to work with a compatible power-up/gravity-down dump trailer hydraulic system. Hydraulic pressure extends the jack to raise the trailer, while compressed air in the jack retracts it. The NeXgen adapter installs in the retract port and gives you a way to add air and maintain the pressure needed for retraction.


Retraction air pressure should be maintained between 80 and 125 psi. Because air pressure can change with temperature, the NeXgen adapter gives you a way to add air as needed to maintain the proper pressure. The compressed-air return also eliminates the conventional return spring found in many single-acting cylinders.


The included 6-port selector valve lets the jack and dump bed share the trailer's existing hydraulic power unit instead of requiring a second pump. The jack itself does not have a built-in manual override, so emergency operation will depend on the capabilities of your trailer's hydraulic power unit.

Plan the Plumbing and Match the Bracket to Your Trailer

This kit includes one 48" hose and one 18" hose, along with the selector valve and fittings needed for the hydraulic connections. Before installation, you should compare those hose lengths with the locations of your pump, selector valve, dump cylinder, and jack. Trailer layouts vary, so planning the routing first helps you choose a practical valve location and determine whether the included hoses will reach where you need them.


The universal eight-hole bracket gives you a bolt-on mounting option when the pattern matches your trailer frame. You should check the bracket and bolt-hole dimensions on the jack to make sure it'll work with your trailer. Mounting hardware is not included, so you can choose the bolt length that fits your frame thickness.


Once it's mounted, glide bearings help prevent contact between the inner and outer tubes, while Stillwell's seal design helps improve cycle life and load holding. A zinc-plated swivel foot and powder-coated steel construction add protection for repeated work around a dump trailer.

Specs

Capacity and Lift:

  • Lift capacity: 10,000 lbs
  • Lift: 26"

Hydraulic System:

  • Operation: single acting
  • Extension: hydraulic pressure
  • Retraction: compressed air
  • Jack ports: (2) #6 SAE ORB female
    • NeXgen adapter installs in retract port
  • Retraction air pressure: 80 to 125 psi
  • Maximum pump pressure: 3,200 psi
  • Designed to share a compatible power-up/gravity-down dump trailer hydraulic system
  • Selector valve: 6-port
  • Manual override: depends on hydraulic power unit used

Connection Kit:

  • Hoses:
    • (1) 48" long
    • (1) 18" long
  • Includes 6-port selector valve and hydraulic fittings/adapters

Jack Dimensions:

  • Retracted height: 35-13/16"
  • Extended height: 61-3/8"
  • Outer tube: 4" x 4"
  • Footplate: 11" long x 8" wide

Mounting Bracket:

  • Bracket: 8" wide x 7-1/2" tall
  • Mounting holes: 8
  • Horizontal hole spacing: 6-1/4" on center
  • Vertical hole spacing: 2" on center
  • Mounting hole diameter: 9/16"
  • Mounting hardware: not included
    • Recommended hardware: (8) 1/2" Grade 8 bolts

Warranty:

  • 2-year limited warranty


02002-9001-0092 Stillwell Single 10K Dump Trailer Conversion Kit 48", Single Acting

SJ001B1DEM4SA Stillwell Atlas IV 10K Hydraulic Trailer Jack with Universal Bracket, with Single Acting Valve

Installation Details ST77VR Installation instructionsAlternate Instructions ST77VR Installation instructions



Video of Atlas IV Single-Acting Hydraulic Trailer Jack w/ 48" Dump Kit - 10,000 lbs - Bolt On
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Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for The Power Behind Stillwell Hydraulic Jacks: Manufacturer Interview

Hello, neighbors. It's Brad here from etrailer, and today, I'm at NATM. And this convention brings a lot of the vendors that we have at etrailer to a convention where we have their booths and their products set up. I had a chance to catch up with quite a few of 'em, so let's take a look at their products a little bit up close and ask some of the questions to those vendors about their products. I'm here with Taylor from Stillwell, and Taylor, what is Stillwell Stillwell is a domestic manufacturer for the trailer industry. Our primary focus is hydraulics.

We've been doing that for nearly the last two decades. We have facilities in Minnesota and Texas and trying to bring as much manufacturing back to the US as we possibly can. Beautiful. So as far as hydraulic jacks, you guys have a few offerings here Yep. What do we have So this one here is our Vaquero.

It's a 10,000 pound lift capacity self-contained unit for primarily horse trailers. We've seen it in a wide variety of applications from the vacuums on Ditch Witch, generator trailers in the oil fields and the tilt trailers that a lot of these customers use in just your equipment and utility space. Brad So tons of different applications. Yep, if we keep moving down the line, we have two different just height options for our Atlas jack. This one is the 20 inch used on a lot of low profile dump trailers.

Super easy tie-in application using some of our proprietary valving. And then we also have a 26 inch option, which is better for your gooseneck trailers. Gives you a little bit more of that extra pipe and travel for those lifted trucks. You know, our industry, they like them a little bit taller. Absolutely.

Now, if someone wanted to add this to one of their trailers, what would they need to do to make sure that your application fits theirs So typically, one of the things we'll do is we'll walk through the current installation process that the manufacturer has, so whether it's bracketed on, welded on, and that'll start to drive the conversation to finding the right solution for you. So, we work with a lot of the OEM manufacturers, so we try to make it as easy as possible with bolt-on applications, plug and play as much as possible. Brad You bet. As far as hydraulics go, we manufacture a wide variety of valving to tie the jacks into the system. So, this one being our dual selector valve is designed to use the existing hydraulics on the dump trailer and allows you with just a flip of this switch to go back and forth between the dump bed and then a hydraulic jack in the front. The original cast iron screw valves, the number one complaint is that they leak, but it's how they work. Like, that's how they're designed, leak. So we came out with a zero leak. It doesn't hydro lock the way that a valve typically would and that's what sets us apart because we we inchesre able to solve both problems. So, it's easy to use. So all the pressure that it takes for me to turn this right now is all it takes under load, versus with the screw valves, that design, because otherwise they'd freeze up and you wouldn't be able to actuate them. So that's where we designed this, but then we provide that to everything about a trailer. So this is our 3-way ball valve. It's designed for the tilt trailers and it's similar application. It's, you lock the system, the trailer's not gonna move. You open it up and now you're able to actually typically grab the tilt. Moving down to one of the other ones, so The Cube here is what is used predominantly on the gooseneck trailers and it's dual flow dividers, dual PO checks so it locks the load in place, makes sure that the flow is even going out and coming back in. And then sure that those jets move in tandem with each other with little to no delay. We also manufacture all of our hydraulic lines out of our facility in Texas, so everything is cut and print, made to order. These have four to one safety factors, so they are designed with safety in mind and again, we adhere to all of your standard SAE qualifications for it. And they're designed to be an easy plug and play with all of our other hydraulic systems. We've standardized all of our adapters to be the same size between the jacks, the cylinders, the valving, so that it's as simple as possible for the end user. For the most part, everything can be completely installed with one wrench. Brad That's awesome. Taylor That's the goal. Now, hydraulic lines, obviously, you don't want damage to those. It's gonna cause a whole lot of issues and a lot of that is setting up the trailer to where you're not gonna have road hazards causing any issue. And so, managing those lines is important, and you guys have a solution for that. Yeah, yeah. So because we've worked with so many different manufacturers and they all weld rings to the trailer, you have to run every hose through, we decided we need to make that easier for one, the manufacturer, and two, for the service after the fact. And so, we came out with these hose clamps here. They're designed to be a peel and stick application. That way, you're not having to run the hose lines through a ring underneath the trailer every three, four feet. They're really easy design. They use VHB tape. So you can just peel the backing off here, and then when you're ready to run your lines, you've got everything figured out. It just fits in there nicely and clamps shut. Yeah, that tape is no joke, too. So if you're worried about an adhesive not holding onto the frame of your trailer, I'm here to tell you it will. It absolutely will. It's super strong. Yep, and everything we do has got a glass field nylon, so it's hardened. It's designed for the road. It's gonna hold up. You could drive over these with your truck and nothing's gonna happen to them. Yeah. That's the way that it's all designed and we put a lot of thought and engineering into the actual use of the product and so we designed it around the trailer. We like to say around here that we don't wanna build the trailer around the products available. We're gonna build the products to build the best trailer. Flip the script on it. I love it. Yeah, awesome. Well thank you, Taylor, for taking the time to break down Stillwell and some of their offerings. Look like fantastic products. Yeah. And I'm excited that etrailer has them. So thanks again, Taylor. Yeah. Appreciate it. Appreciate it, Brad. Thank you so much.

Ratings & Reviews

4.5

30 reviews
Review sort icon
Upgrade your power-up/gravity-down dump trailer from manual cranking with a 10,000-lb Atlas IV jack. Hydraulic pressure extends the jack, compressed air retracts it, and the 48" kit includes the valve, hoses, and fittings.

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Upset that I had to pay an additional 250.00 for two longer hoses and one shorter hose. The two short hoses from the pump to the transfer valve should have been the same size. One was 6 inches longer.
The long hoses from the jack are way to short.
Also the packaging was terrible. Box was all ripped up and taped. Lots of scratches.



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Works good



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Packaging was all ripped open haven’t installed yet



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product it self is good, jack is quality, controls and hoses are high quality the dumb part is no instructions or labeling on the control valve- so its trial and error for hose installation. jack mount is odd pattern so you will be fabricating in some way to mount it-



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Very heavy duty a lot more than I expec ted



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Great place to buy your equipment needs, thanks



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Have not installed it yet but appears to be very heavy duty built. Cant wait to use it.



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This rating is based on the product description. I can’t install it due to some extremely short hoses. While shopping I assumed the “39 in.” vs the 48 in. meant the hose length and it does. For the long hose anyhow. The short hoses are so short they limit the positioning of the transfer switch. If I put the switch close enough to use the short hoses, then the long hoses are too short. None of this hose length is shown in the product details. Now I have to get custom hoses made. I would seriously consider ordering without hoses as these hoses are stiff and positioning and placement make it difficult without custom sizing.



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Jack works exclent. Installed with minimal problems had to redrill the mounting holes but no problem



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The most difficult part was removing the old mechanical welded in jack. Wound up using a combo of a cutting wheel and a plasma torch. One the new jack was in position, I welded it complete, painted the area, hole sawed two 1" holes in the pump storage box, installed grommets and completed the plumbing. Bleed the jack per the instructions I found online and it worked like a champ afterwards. My only complaint would be that there were no instructions what so ever but was able to locate them online with Stillwell, the manufacturer.



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Product is good and works well. No instructions provided for the diverter valve. A quick phone call and they emailed me those instructions.



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I didn’t know the bolt holes were not going to line up with my trailer holes….. other than that it was fine to install



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Jack extremes no problem but does not retract up. Sellers has no clear instruction on installation.

Nick S. profile picture

Nick S.

12/15/2025

I am sorry to hear you are having trouble getting the Atlas to retract. We will reach out shortly and help troubleshoot through this.


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25

See what our Experts say about this Stillwell Trailer Jack


Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Dustin K
Video Edited:
Dustin K
Employee Steven C
Installed by:
Steven C
Employee Wilson B
Updated by:
Wilson B
Employee Amanda M
Updated by:
Amanda M
Employee Alex H
Updated by:
Alex H
Employee Kim H
Written by:
Kim H

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