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Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs

Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs

Item # JSP-100
Our Price: $5.50
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Attach a layer of support when mounting your jack to your A-frame trailer coupler. Fits 2,000-lb to 5,000-lb A-frame jacks. Raw finish with light oil allows for easy welding. 1-800-940-8924 to order etrailer accessories and parts part number JSP-100 or order online at Free expert support on all etrailer products. Great prices and Fastest Shipping for Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs. Accessories and Parts reviews from real customers.
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  • Reviews (28)
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  • Videos (1)
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etrailer Accessories and Parts - JSP-100

  • Camper Jacks
  • Trailer Jack
  • Plate
  • Support Plate
  • etrailer

Attach a layer of support when mounting your jack to your A-frame trailer coupler. Fits 2,000-lb to 5,000-lb A-frame jacks. Raw finish with light oil allows for easy welding.


  • Support plate adds stability to help keep your A-frame trailer jack from leaning
  • Bottom-mounted plate attaches to the underside of your trailer frame
  • Sturdy steel construction
  • Weld-on installation
    • Raw finish for easy welding


  • Fits jacks with 2-1/4" outer tube diameter
  • Jack hole diameter: 2.29"
  • Weight capacity: 5,000 lbs
  • 1-Year warranty

JSP-100 Ram Bottom Support Plate for 2-1/4" A-Frame Trailer Jacks - 2,000 lbs to 5,000 lbs

Video of Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for etrailer Trailer Jack JSP-100 Review

Today, we're going to be taking a look at a bottom support plate for a 2-1/4" outer-diameter A-frame jack with a capacity of 5,000 pounds. This support plate is going to add stability to keep your A-frame trailer jack from leaning under heavy loads. It's a bottom-mounted plate that attaches to the underside of your trailer frame. It's made from a sturdy steel construction. This is a weld-on installation. It's a nice raw finish for easy welding, so there's no prep work for it. This is designed to fit jacks with a 2-1/4" outer-tube diameter.

We can tell that by taking a measurement of the diameter of the hole right here at the center of the plate. It's going to be just a hair over 2-1/4". The exact measurement is going to be 2.29", but it is designed for a 2-1/4" outer-tube-diameter jack. Again, it's going to have a weight capacity of 5,000 pounds. A few measurements I want to go over with you real quick. The thickness of the plate is 1/8".

Again, steel construction. If we take an overall length measurement here at the back, that's going to give a measurement of 8-3/4". Here at the front, that length measurement is 5-1/2". The diagonal measurement right here, it's going to be the same for the other side. That's going to measure 3-7/8".

Then from front to back right here at the center, the straight-line measurement is 3-1/2". That's going to do it for today's look at the bottom support plate for 2-1/4" outer-tube-diameter A-frame jacks.

Customer Reviews

Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs - JSP-100

Average Customer Rating:  4.5 out of 5 stars   (28 Customer Reviews)

Attach a layer of support when mounting your jack to your A-frame trailer coupler. Fits 2,000-lb to 5,000-lb A-frame jacks. Raw finish with light oil allows for easy welding.


Storage crew told me to STOP when I backed into the building...when my RPod popped off the hitch ball it rolled forward about three inches, bending the existing jack mount plate and leaving the jack at an approximately 15-degree angle. Mad? -- you bet...THIS will support the lower side of the jack after the trailer repair outfit straightens the upper mount. Thanks!


I would have given the product an excellent rating but the manufacture did not de-bur the cut edges. Luckily no one got cut. After de-burring the cut edges with a bench grinder the product was what would be expected.


The delivery was earlier than expected.The part is exactly as the description.


It needs to be thicker metal. My trailer came with one exactly like this one from the factory. Someone before me tried to drive off with the jack down and ripped through the old one. Which in turn bent the L out of the hitch. The hitch was so bent there was no way to repair it and mount a new jack. So I am having to replace the hitch as well as this weak plate. If this piece had been strong enough to hold instead of tearing in two, it wouldn't have bent the hitch. The jack would be ruined but then the jack was ruined anyway. It would only have cost the price of the jack. Not the jack, hitch, and this plate. Probably order a second one and add to this one. It needs to be at least twice as thick.

Like my original post, it needs to be thicker, but it works like it should. A must have for all trailers not equipped with it from the factory.
Steven - 07/11/2021


Good quality fast shipping.


While these may be good to weld on, most of the trailer jacks that I have seen are the 3 bolt triangular style. These don't work well with them since the front part is too short to cover the entire bolt hole. So these would only be useful in a weld on style jack configuration, not a bolt in.


I used two of these to convert my side mount jack to an A frame jack without replacing my hitch receiver. With a few modifications they work great! Super happy!


The product I received was exactly what I ordered and appears to be of excellent quality. It was delivered in a timely manner with no issues.
I have purchased other items from and expect to purchase more in the future!


etrailer exemplifies customer service. On top of providing one of the widest selections of quality products their follow through and fast shipping keep me coming back for more.


I’m rebuilding a 1977 Jayco Finch pop-up trailer. With a little trimming this bottom support worked great! Just like OEM.


Exactly what I needed. Even got to practice my limited welding skills to put it on. Hardest part is cleaning up the mess the old rusted out on left. I primed a painted this one after installing.


The plate is as described. Unfortunately does not cover all holes on trailer completely.


This is 1/8 inch steel So it’s really hard to weld. If they made it with a thicker material I think it would be a lot better.


Product was great fit perfectly and easy to install!
E Trailer shipped the part out right away, really happy with their service.


Prompt delivery. Just what I needed. Adds much stability to my jackstand.


worked great


good products and great service.


I welded it to the frame and it holds s olid.


It was exactly what I wanted.


Just what I needed.





Exactly as advertised


Show More Reviews

See what our Experts say about this etrailer Accessories and Parts

  • Recommended A-Frame Jack Mounting Support Plate For Standard 3 Inch On Center Mount
    The Lippert Components # LC285318 uses a standard 3 inch on center bolt pattern. You will most likely need to drill some new holes in your coupler to allow for the standard mounting when replacing your trailer jack. I recommend the Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs # JSP-100 if you are concerned about the stability in that location with the additional holes.
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  • Steel Thickness for A-Frame Trailer Jack Support Plates for 2-1/4 Inch Jacks
    The A-frame trailer jack support plates for 2-1/4 inch jacks are all approximately 1/8 inches thick. There are some manufacturer tolerances so one might be slightly thicker than the next. And models that are raw steel like # BD003135 are more uniform in size compared to the ones that are powder coated. I have included a link to the options. Not all of them are for 2-1/4 inch jacks and there is also a square one in there but the majority are for 2-1/4 inch round jacks.
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  • Dimensions of Lippert Smart Jack Above The Frame For a Boat Trailer Jack
    The Lippert Smart Jack Electric Trailer Jack w/ Footplate # LC643589 has the following dimensions above the mounting plate. It is 21.6" tall, 6.165" wide at the widest point of the head and 9.385" deep at the widest points. I have included an image to help you see these measurements. The manual override nut on the jack is a 19mm hex head bolt. I recommend the Bottom Support Plate # JSP-100 for helping you to create a mount on the frame of your boat trailer to hold the Smart Jack.
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    Image 1 for Image 2 for
  • Availability of A-Frame Trailer Jack With Tube Diameter Of 1-7/8" or Less For 1967 Vintage Trailer
    I do have an option for you, but there is not an A-Frame trailer jack offered with a 1-7/8" or smaller outer tube diameter as 2-1/4" is the standard. What you will need to do is replace your bottom support plate with the # JSP-100 instead as this has the 2-1/4" opening to match your upper hole. Once that is done you can use any of the A-frame jacks as the 3 bolt 3" bolt pattern you have is standard, but based on the specifics you were looking for I recommend the Buyers Products A-Frame...
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  • Recommended Plates for Installing Electric Jack Mount on A-Frame Trailer
    Thanks for the photos. You will need to weld on a plate like the Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs # JSP-100. It sounds like you will need a couple of these plates to create a bracket instead of a reinforcement because it will need to be strong enough to support the tongue weight of the trailer. Then the Stromberg Carlson Electric Trailer Jack - Drop Leg - A-Frame - 23" Lift - 5,000 lbs - Black, Item # JET-5000 is a great option for your trailer.
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  • Dimensions Of Bottom Support Plate JSP-100
    The Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs # JSP-100 you mentioned is 1/8" thick, has a hole diameter of 2.29", 8-3/4" long at the back, 5-1/2" long at the front, the diagonal sides are 3-7/8", and front to back is 3-1/2" as shown in the included diagram. I included a video of the # JSP-100 for you to take a look at.
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    Image 1 for
  • Recommended Jack Support Plate When Installing Demco A-Frame Trailer Coupler DM14791-97
    For the Demco A-Frame Trailer Coupler w/ Jack Hole - eZ-Latch - Primed - 2" Ball - Weld On - 10K # DM14791-97 you were looking at you can use the Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs # JSP-100 to replace your current jack support plate. I included videos for each of the products mentioned for you to take a look at.
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  • Footplate Recommendation for the etrailer Round A-Frame Jack # TJA-5000S-B
    I believe you are looking for a footplate for the etrailer Round A-Frame Jack, # TJA-5000S-B. If so, then you can use the Footplate for 2,000-lb and 5,000-lb Round, A-Frame Jacks # JF-99. This foot plate attaches to the inner jack leg using included pin. Since you will be installing this jack on a dump trailer, I recommend using the Bottom Support Plate for 2-1/4" OD A-Frame Jacks - 5,000 lbs # JSP-100. Dump trailers can be loaded pretty heavy, and this plate will help support the jack...
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  • Highest Lift for A Frame Trailer Jack With 5,000 lb Weight Capacity
    We have a jack that meets all of the requirements that you are asking about. The Round A-Frame Trailer Jack # TJA-5000S-B has a lift, or travel, of 15-5/8 inches. When this jack is fully extended, the bracket height it 24 inches. This jack also features an easily accessible grease zerk for maintenance and has a support capacity of 5,000 lbs. Since this jack doesn't come with a foot, I recommend using part # JF-1005H-Z to help stabilize your trailer. If you would like a bottom support plate...
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Info for this part was:

Employee Cole B
Installed by:
Cole B
Employee Wilson B
Updated by:
Wilson B
Employee Ronnie R
Updated by:
Ronnie R
Employee Mike S
Updated by:
Mike S
Employee Amanda M
Written by:
Amanda M

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