bing tracking image
  1. Trailer Leaf Spring Suspension
  2. Redline
  3. Camper
  4. Car Hauler
  5. Utility Trailer
  6. U-Bolt Kits
U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles - 4-1/4" Long U-Bolts

U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles - 4-1/4" Long U-Bolts

Item # APUBR-10
Our Price: $35.16
Trailer Leaf Spring Suspension
Orders above $50 qualify for Free Shipping
Shipping Weight: 3 lbs
In Stock
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

Customer Photos

Need help with installation?
Locate installers near me
Mount your round, 1-3/4" diameter axle to your trailer's leaf springs with this U-bolt kit. U-bolts, plates and nuts included. Great Prices for the best trailer leaf spring suspension from Redline. U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles - 4-1/4" Long U-Bolts part number APUBR-10 can be ordered online at or call 1-636-306-4830 for expert service.
  • All Info
  • Reviews (379)
  • Q & A (0)
  • Videos (2)
  • Photos
  • Why etrailer?

Redline Trailer Leaf Spring Suspension - APUBR-10

  • Camper
  • Car Hauler
  • Utility Trailer
  • U-Bolt Kits
  • Round Axle - 1-3/4 Inch
  • 4-1/4 Inch Long
  • 2000 lbs
  • 3/8 Inch Diameter
  • Redline

Mount your round, 1-3/4" diameter axle to your trailer's leaf springs with this U-bolt kit. U-bolts, plates and nuts included.


  • Attaches trailer axle to leaf springs
  • Includes:
    • (4) 4-1/4" Long U-bolts (175643)
    • (2) U-Bolt plates for 1-3/4" springs (117535)
    • (8) 3/8"-24 Hex nuts (38N)
  • Spring seats required for mounting axle to leaf spring sold separately


  • Axle diameter: 1-3/4"
    • Typical 2,000-lb axle
  • Spring width: 1-3/4"
  • Dimensions: see below

U-Bolt Diagram

APUBR-10 U-Bolt Kit for 2,000-lb Round Trailer Axles

Video of U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles - 4-1/4" Long U-Bolts

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

Video Transcript for Redline Round Trailer Axle U-Bolt Mounting Kit Review

Randy: Hey guys, it's Randy here at Today, we're going to be taking a look at a replacement U-bolt kit. This is going to be designed for the 2000 pound axles, looking for an inch and three-quarter axle diameter. You can see how they're designed to fit around your axle with an incorporated plate here and hold that axle to your spring pack.Now, I think it's crucial anytime you replace an axle that you replace these U-bolts. Over time, of course, they're going to get stressed and they're going to get strained. They can even stretch out on you.

And basically by getting a new set, not only do we have new hardware, so we don't have to worry about any cross-threaded situations, we get new lock washers and a new plate down here, by getting these new U-bolts, you can rest assured that your axle is going to be held securely to your spring.When we just throw our old U-bolt kit back on there and we start torquing it down, there's no way for us to know for sure that it's actually holding to the values that we want. So definitely keep that in mind. I think that anytime I replace an axle, I always get a new U-bolt kit for it. Talk to our customer, explain to them the benefit and let them know that by replacing that you get that peace of mind and you know that you're not going to have any issues with it down the road. And oftentimes it's hard to get the old nuts off.

They're usually rusted onto the U-bolts and you generally have to wind up cutting them. So in my mind, if you're ordering an axle, definitely get a replacement U-bolt kit. So when you do get everything there, you're not running around trying to find it. It's a very cost-effective way to freshen everything up and get it ready to go.Now, when we install our U-bolt kit, essentially we'll take two of the U-bolts and they need to go around our axle. In our case, our axle's sitting on top of the spring so we put the spring perch right on the bolt that sticks out, because that's going to be sitting right in there, right in the middle.

Then our plate needs to go on the opposite side of that. And if we look down low, you'll see that bolt's also going to come through the center hole on that. The two outside holes, we've got our U-bolts that come down through. Then we're going to place a lock washer and we're going to place a nut on each one. Once we've got that done, we need to equally tighten these down to get them nice and snug.

Then we'll torque them to specifications. Now we'll just head over to the other side and repeat that same process there. We'll be ready to go..

Customer Satisfaction Score:

Customer Reviews

U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles - 4-1/4" Long U-Bolts - APUBR-10

Average Customer Rating:  4.7 out of 5 stars   (379 Customer Reviews)

Mount your round, 1-3/4" diameter axle to your trailer's leaf springs with this U-bolt kit. U-bolts, plates and nuts included.


I purchased two of these axles to replace my old square ones. They appear to be good quality but they arrived damaged. The grease fittings on the ends were smashed because packaging wasn't adequate. I've emailed back and forth and was shipped the wrong parts for replacement. In the end I was told I'd have to cut the spindles off and replace them. All I need is new grease zerks that thread on the ends of the axles. Be prepared to purchase these on your own because customer service is subpar on a remedy and the way they package them for shipping does not prevent damage.


The knowledgable team at etrailer helped me find the perfect fit parts for relocating my leaf spring mounts on my 1993 coleman destiny Cedar trailer. Installation went smooth and has been issue free for 1500 miles.


Ubolts were correct however bottom plates were not wide enough for 2" springs.

As mentioned above in the product specs, the plate is designed for 1-34 inch wide leaf springs.
-- Etrailer Expert Mike L - 09/21/2022


I purchased this kit for the standard 5' x 8' 2,000 lb. trailer from Lowes. I did an axle flip and added larger tires. This is the perfect kit for this trailer. It went on easy, and the bolts were slightly longer. Also the bolts in this kit were fine thread instead of course thread. Overall an improvemet over the factory hardware and I had no issues. Shipped in a timely manner and packaged well.

I highly recommend this kit if you plan on flipping the axle or need a replacement.


Bought these to replace some badly rusted bolts and plates, they fit perfectly and have held up great for the past year.


The u bolts are fine, I'm shocked the nuts are not self locking, and do not come with lock washers.


Dont hesitate ordering from ! You have a great website with detailed measurements which made ordering the parts I needed extremely easy. After ordering I received an email with very detailed shipping info. You shipped my package very quickly and your tracking info that you provided in the email you sent is definitely the best I have ever experienced! Customer service has become a thing of the past. But not with ! Keep up the great work and Thank you!


Looked under my trailer and the u bolts and plates wer rusted away, it's an old trailer so I had no details like make or model number. Called and talked to Kelly S. She was very knowledgeable and overly efficient! Got my parts super fast, the u bolts wrer very thick and the plates were even thicker. Quality parts at a good price. Would highly recommend and a big thanks to Kelly

A year later still going strong
Mike T - 02/29/2016


Great quality. I did go to with some nylon lock washers. The mounting plates where much better quality and fitment than what the trailer came with stock.


Parts worked great, did my axel flip giving my pop up some better ground clearance and pulls like a champ!


I think that instructions would be a good thing to include with the parts. Also the tube of grease was open when I received the package.


Web site very informative on product. Follow up call to vendor on questions I had about the product were answered quickly and accurately. Quick delivery. A very good experience.


I inherited an aluminum trailer that ended up needing a complete overhaul and etrailer was the best resource I could have found. After researching extensively to find out what I needed and watching their videos on how to do it I ended up ordering an EZ-lube axle, galvanized hubs, springs and a hanger kit (in other words everything from the frame down).
Everything shipped quickly and arrived in great shape. All the parts worked perfectly and I couldn't be happier!


Perfect fit, went on easy

Just fine, been taking apart an old 8000 lb shear pc by pc and taking to scrap yard on that small trailer, heavy parts sometimes, u bolts holding up fine
Edward - 11/06/2022


This is my go to place for all things t railer/towing.



so far so good
David - 11/07/2022


they are U-bolts and they did fit. smaller bolt size than what i removed, but that is my mistake.


These should include lock washers or jam nuts. There is nothing to keep them tight. I added lock washers and jam nuts for added tightness. Extremely fast shipping. Well packed.


Fit perfectly, worth every penny, never worth messing around with old hardware


Old spring seats were rusted away, replaced the seats and u bolts, etrailer showing the measurements makes it easy to know you are getting the right parts


After returning the part that didn't fit. My mechanic had no problem putting the corrected axle on and was finished in 30 minutes. Thank you so much for helping me Steven R. So far it is working great.


Good quality fast shipping


Fit well and seems to be a good quality.


Not much to say, they went in fine, and secure the axle to the spring seats...


I'm well pleased great quality and very fast shipping excellent company I will be recommending to all my friends.

Show More Reviews

See what our Experts say about this Redline Trailer Leaf Spring Suspension

  • What Torque Should Be Used For U-Bolt Nuts On Trailer Suspension
    If the U-bolts are 9/16 inch diameter, the torque specs should be between 65 to 95 foot lbs. If the U-bolts are 3/8 inch diameter, the torque should be between 30 and 50 foot lbs.
    view full answer...
  • Is Trailer Suspension U-Bolt Plate Supposed to Bend and What is Torque Spec for 3/8" U-Bolts
    Trailer suspension U-bolt plates can bend, yes, so it doesn't sound like you have anything to worry about. For 3/8 inch nuts on the U-bolts in kit # APUBR-10 they should be torqued between 30 and 50 foot pounds according to Dexter Axle.
    view full answer...
  • Replacement Parts for Long Chih Industrial LCI-850T Folding Utility Trailer
    The website for Taiwanese trailer maker Long Chih Industrial does not provide any specs or construction details for their LCI-850T folding utility trailer so I cannot tell you which parts you will need to complete assembly. However, we do offer all sorts of trailer hardware like u-bolt kit # APUBR-10 as well as other individual parts you can see on the linked page.
    view full answer...
  • U-Bolt Suspension Kit for 1-3/4 Inch Diameter Round Trailer Axle
    U-bolt kit # APUBR-10 is the only one we carry that fits a 1-3/4 inch diameter trailer axle. You would have to change the springs to 1-3/4 inch wide springs to use this kit. A larger u-bolt kit would not work because it can cause damage. To determine if we have springs that will work for your trailer I will need to know the type of springs you have, double-eye or slipper springs, and the measurements. A 1-3/4 inch diameter axle likely has a 2,000 pound capacity so we would be looking at...
    view full answer...
  • Availability of 3/8-Inch Diameter U-Bolts that Measure 4-inches x 3-1/2-inches
    We do offer several different u-bolts and axle kits with 3/8-inch diameter and all of these can be seen on the link at right. One such example is part # APUBR-10 which is a kit with 4 u-bolts, plates and nuts. None of these has the exact dimensions you quoted, please note. A second link will let you see all u-bolts we offer and the filters in the left-hand margin will let you sort the results based on length.
    view full answer...
  • U-Bolt Kit for 1-3/4" Round Axle
    There is a kit for 1-3/4 inch round axles, the U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles - 4-1/4" Long U-Bolts # APUBR-10. That said, these are for 2,000 lb axles that are found on RVs instead of a mobile home axle. The reason for that is mobile home axles are designed for a one-time use so people don't change the suspension. I have added a link to a video review of this kit for you to check out as well.
    view full answer...
  • U-Bolt Mounting Kit For A 1,500 Pound Round 1-3/4 Inch Axle
    The U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles # APUBR-10 is the correct kit for you. This kit includes 4 U-Bolts, 2 U-Bolt Plate and the hex nuts needed to install to your axle. I attached a review video link below.
    view full answer...
  • Can Trailer Leaf Springs be Moved from Below the Axle to the Top of the Axle
    Some trailers have the leaf spring stack above the axle and some have it underneath. You can move the stack to the top of the axle but you will have to weld on new spring seats to the top of the axle. Use # TRSS175 for a 1-3/4 inch round axle. It will raise the height of the trailer some but you need to be aware that it also raises the center of gravity. That makes the trailer more susceptible to sway.
    view full answer...
  • Replacing Suspension Hardware For Harbor Freight Single Axle Trailer With Slipper Springs
    The first thing you will need to determine is what the weight capacity of the trailer is. There should be a plate or sticker on the trailer or on the axle with those numbers. We offer a 2-leaf slipper spring, part # SP-179275, for 2,000-lb axles. I have attached a drawing of a leaf spring with the dimensions for the SP-179275 leaf spring you can check out. These springs measure 1-3/4 inches wide and have an eye diameter of 9/16 inch. The U-bolt mounting kit for these springs is part...
    view full answer...
    Image 1 for
  • Recommended Springs and Ubolt Kit for 1993 Tacker Trailstar Boat Trailer
    Sounds like the 3-Leaf Double-Eye Springs # SP-219275 are what you are looking for. They have an eye to eye distance of 25-1/4 inches, a width of 1-3/4 inches and are rated for 2,500lb trailer axles. The ubolt kit # APUBR-10 should provide you with enough clearance. This ubolt kit is designed for 1-3/4 inch round axles and are 4-1/4 inches long and the ubolt post has a diameter of 3/8 of an inch. See the picture I've attached. I have linked both items to this page for your convenience....
    view full answer...
    Image 1 for
  • Over Under Kit Recommendation for 1-3/4 inch Axles
    I wish we had something we could offer you, but none of the spring seats we offer are designed to fit a 1.9 inch diameter axle. The closest we have is the 1.75 inch spring seat like part # TRSS175 which wouldn't work unless you happened to incorrectly measure your axle diameter and you do have 1-3/4 inch axles. The rest of the parts you would need would come in the kit part # APUBR-10.
    view full answer...
  • Does Over Under Kit for 1-3/4 inch Axle Require Welding
    All you would need for an over-under kit for a 1-3/4 inch round axle would be the U-bolt kit part # APUBR-10 and the spring seat part # TRSS175 that you referenced. You would need two of the spring seats. You will need to weld the spring seats into place.
    view full answer...
  • Changed Trailer Deck From Steel to Wood Now Tires Rub Fenders When Towing A Load
    We carry over-under conversion kits that fit both a 2-3/8 and 3 inch axles. However, we do not offer a kit that will fit a 2,000 lbs axle, but we can put together a conversion kit for you that will work with your axle. You will need U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles, # APUBR-10 and 2 of Spring Seat, # TRSS175, for 2,000 lbs with 1-3/4 inch diameter. You will place a spring seat on the top of the axle to provide a place for your leaf spring to sit. The new spring seat...
    view full answer...
  • Possible Solution for Bent A-Frame Trailer Due to Swivel Jack
    The frame members of a trailer really aren't replaceable. Your best option will be to take the trailer (carefully) to a fabricator to see if they weld in a new section of frame there. You should also have them go over the trailer to make sure there aren't any other structural issues that need addressing as well. Also be sure not to overload the trailer. It looks like it bent where the swivel jack was initially installed. You might have that front section of the trailer reinforced with another...
    view full answer...
  • Spring Hanger and Axle Diameter Measurements for Installing Leaf Springs on Single Axle Trailer
    In the attached diagram the A measurement is actually the distance from the center of the spring hangers for a single axle trailer. The spring eye to spring eye measurement for your leaf springs will be slightly different. The B measurement that you see is simply the distance between the center of the axle and trailer frame. I have attached another diagram from the Single-Axle Trailer Hanger Kit for Double-Eye Springs # APS3 product page to help demonstrate this. If you have an axle with...
    view full answer...
    Image 1 for Image 2 for
  • Axle Flip Kit to Lower Trailer with 2,000 Pound Axle
    We recommend having at least 4 inches of clearance between the top of the tire tread and your fender or trailer floor to account for suspension travel. If the leaf springs are currently over the axle on your trailer and you want to move them below it to lower the trailer then you will just need a U-bolt kit and new spring seats. You will want to verify this but most likely your 2,000 pound round axle features a 1-3/4 inch diameter. For this the U-Bolt Kit # APUBR-10 and the TruRyde Spring...
    view full answer...
  • Parts Needed to Flip Axle on a Pop up Camper
    I have exactly what you need, but it will have to come in the form of a couple parts pieced together because an over-under conversion kit or "axle flip kit" as some people call it isn't available for the smaller 1-3/4 inch round axles. To move your leaf springs above your axles, you will want the following parts: Qty 2 - Spring Seats # TRSS175 Qty 1 - U-Bolt Kit # APUBR-10 The spring seats will be welded to the opposite side of the axle as the current spring seats. You may not need the...
    view full answer...
  • How to Make Over-Under Conversion Kit for 2K 1-3/4" Axle on 5x8 Utility Trailer
    I'm pretty confident you have a 1-3/4" round tube axle on your Carry On 5x8 trailer. Having a 2" axle is uncommon and is typically only found with square tube axles, which you don't have on your trailer. While there isn't a specific over-under conversion kit for a 1-3/4" axle, you can use 2 of the spring seat # TRSS175 and weld them on either end of your axle, and then use the U-Bolt kit part # APUBR-10 to finish out your own conversion kit! Please note that you need to have a qualified...
    view full answer...
  • Correct Spring Seat and U-Bolt Kit for my 1-3/4" Round 2,000 lb. Axle
    The Spring Seat for Typical 2,000-lb, Round Trailer Axles with 1-3/4" Diameter part # TRSS175 are confirmed to work with the U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles part # APUBR-10. The U-bolts are always slightly wider at the mouth than at the bend and they all fit together really well.
    view full answer...
  • Axle Flip Kit for a 1,000 Lb to 2,000 Lb Trailer Axle 1-3/4 Inch Diameter
    I have a solution that will allow you to flip your axle but there is not an all-inclusive kit for your axle size so we will need to piece together one. I assume you have a 1-3/4" diameter axle (1,000 lb - 2,000 lb) so that means you will need the U-Bolt Kit part # APUBR-10 and the Spring Seat part # TRSS175 (2). These u-bolts are 4-1/4" which is the longest we have for this width. However, I would highly doubt that you will require a 6" long u-bolt as most leaf springs are only 3/8" thick....
    view full answer...
  • Parts Required to do Over/Under Conversion on 1-3/4 Axle on Tractor Supply Trailer
    From what I was able to determine the Tractor Supply trailer you have likely has a 2000-lbs axle on it, which has a 1-3/4" diameter axle. There isn't a specific over/under conversion kit for that size axle but you can use 2 of the spring seat # TRSS175 and weld them on either end of your axle and then use the # APUBR-10 u-bolts you were looking at to complete the process. It should be noted that you need to have a qualified welder perform the installation of the spring seats.
    view full answer...
  • How to Make a Trailer Axle Over Under Kit for 1-3/4 inch Round Axles
    All you would need for an over-under kit for a 1-3/4 inch round axle would be the U-bolt kit part # APUBR-10 and the spring seat part # TRSS175. You would need two of the spring seats.
    view full answer...
  • Replacement Double-Eye Leaf Springs for 25-1/8" Eye Center Length
    All of our double eye leaf springs are 1-3/4" wide. If you have 1-3/4" wide springs we have the 3-Leaf Double-Eye Spring for 2,500-lb Trailer Axles # SP-219275. This spring has a 25-1/8" eye center to eye center measurement and is rated for 1,250lbs per side. You will want to verify that this is the correct capacity for your trailer. I recommend using a U-Bolt Kit # APUBR-10 as often the U-bolts are damaged or severely corroded. If your springs are different from what I have recommend...
    view full answer...
  • Parts Needed to Flip 2,000 Pound Axle With Slipper Springs
    Technically the over-under conversion kit can be used with slipper springs if the spring seats are fully welded to the trailer axle and you would have to use a u-bolt plate that fits the springs. Since you have a 2,000 lb axle this doesn't matter since there is not a kit that fits a 1-3/4" diameter axle like the one you have. You can do the same thing with the U-Bolt Kit for Mounting 2,000-lb, Round Trailer Axles - 4-1/4" Long U-Bolts # APUBR-10 assuming you have 1-3/4" slipper springs....
    view full answer...

< Previous
123. . .5

Do you have a question about this Trailer Leaf Spring Suspension?

  • Why

    At we guarantee:
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate trailer leaf spring suspension information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Adam R
Expert Research:
Adam R
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Kathleen M
Video Edited:
Kathleen M
Employee Dustin K
Video Edited:
Dustin K
Employee Cole B
Installed by:
Cole B
Employee Shane T
Installed by:
Shane T
Employee Randy B
Installed by:
Randy B
Employee Chris R
Video by:
Chris R
Employee Zach D
Video by:
Zach D
Employee Alexander C
Updated by:
Alexander C

At we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.