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2-3/8" Round Trailer U-Bolts (Qty 2)

2-3/8" Round Trailer U-Bolts (Qty 2)

Part Number: SP01-040
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Great Prices for the best trailer suspension parts from Redline. 2-3/8" Round Trailer U-Bolts (Qty 2) part number SP01-040 can be ordered online at or call 1-800-940-8924 for expert service.
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Redline Trailer Suspension Parts - SP01-040

  • U-Bolts
  • Camper
  • Car Hauler
  • Utility Trailer
  • Round Axle - 2-3/8 Inch
  • 5-1/2 Inch Long
  • 3500 lbs
  • 1/2 Inch Diameter
  • Redline

Round Trailer U-Bolt
  • 2-3/8" Wide
  • 1/2" Diameter
  • 5-1/2" Long
  • Includes Lock Nuts
  • Torque:
    • Minimum: 45 foot lbs
    • Maximum: 70 foot lbs

Video of 2-3/8" Round Trailer U-Bolts (Qty 2)

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

Video Transcript for 3 Inch Round Trailer U-Bolts Installation

Hi there trailer owners. Today we're gonna be taking a look at red lines line of replacement U bolts. Round U bolts are commonly used to hold your leaf spring stack onto your axle. And if you're making any repairs to your trailer it's possible that the threads can get damaged where you can't reuse the U bolt. You might have to replace them in that instance, or if you had some sort of blowout or any other kind of damage where you might've had some damage that caused some issues with your U bolts here you may need to replace those as well. Over time if you've constantly taken these off they do stretch out over time.

So it is a good idea to replace them. If you've had several repairs done and remove them. The ones that redline have, offer slightly longer length. So that way you can ensure it's going to be a fit for your trailer. We also recommend these.

If you're gonna be adding accessories to your trailer and you need the additional length if that accessory goes under a U bolt we can see our factory U bolt here on the trailer We we're just working on if we wrap it around and we can see it only goes up about that high. This is about six inches in length. The new one here that we put on is about seven inches in length and it gives us the extra length that we needed to be able to install the mounting plate for the shock absorbers that we just installed on here. With our factory U bolt we'd have almost no threads here sticking out. So our nut would be able to go on but it wouldn't be able to be properly torqued with enough threads to ensure that it's gonna stay torqued in that position.

Today, we're showing off the three inch wide U bolts with a half inch diameter. These have a seven inch length, and we're gonna use those to get our comfort ride system installed but we have them available on all the various sizes. So that way you can ensure you got a replacement for your trailer. We have them down as small as an axle diameter of one and three quarters of an inch. That's going to be your 2000 pound axles all the way up to an axle that is five inches in diameter.

And that's gonna be your larger axles that are around 12 to 15,000 pounds. Now the diameter of the U bolts do change as the sizes go up.Your smaller ones that only are for the one and three quarter inch axles typically have a size of three eights and of diameter while your large ones, with that five inch wide axle length is going to have a diameter of a U bolt of about three quarters of an inch to ensure that it can handle that weight rating of that. Now there are a couple of different U bolts that do have an overlap. The three inch ones that we're using here also have another three inch version available. That's in a nine 16th diameter. So you want to just check your trailer and your old U bolt to make sure you're replacing it with one that's going to be accepted acceptable with the hardware that you have on here. Cause we wouldn't be able to take a nine 16th and slide it through these brackets because the bracket on here was designed for a half inch. Replacing your U bolt is pretty easy. The smaller your trailer is usually the easier it is. Those larger U bolts. You are going to need to have a little bit more strength required to remove and torque down the nuts ' cause they are typically a higher torque value for the larger the U bolt. When taking them off you wanna make sure your axle is properly supported. If you follow along with us, we'll show you an example of how to remove and swap out the U bolts. We'll begin our installation by parking our trailer onto level ground. Your driveway in most cases is a great spot and lifting it up and removing our wheels. You'll wanna Jack it up and support the frame with Jack stands. You have to get it high enough off the ground where your wheels are off the ground so you can get those pulled off. And once you've got those pulled off here you are set up to begin working. We're using a lift here on ours to hold ours up. But again, it's gonna be very similar at home. You're just not gonna have the cross beam with the lift. You'll have just these Jack stands here underneath your frame. Now the Jack stands that I've got here. These are just precautionary Jack stands that are underneath the axles because we're going to be taking the U bolts loose. And once we take those loose, the axle can drop down. But I also have my Jack here underneath the axle and I'm gonna be moving this Jack around and keeping it under the axle that I'm working on this 'cause the Jack stands are really just supplementary in case something happens. My Jack, where two something we're to happen to the Jack with a fluid leak out we got a Jack stand here to support it. So we're going to remove the nuts here on top to take these U bolts off, the U bolts that are on your trailer. Aren't gonna be long enough to accept the brackets for the comfort ride system. So we are going to be replacing these U bolts. You can get new U bolts here at etrailer. Once we get these off, we'll show you the new U bolts. We're using a three quarter inch socket to remove the nuts, they are gonna be on there little snugs if I have to start it by hand, and then your tool can zip it off easily the rest of the way. Now we've got these all zip loose. We can pull our U bolts out of there. They just pull down. They're usually a little bit stiff. So just kind of working back and forth and just pull downward, come out of there. You can also kind of rock the top piece here. sometimes that helps . If you pull it over like this you can kind of get a little bit of a bang motion on it. To help persuade it off of there. So now we've got our factory bracket out of the way. This is your comfort ride. Your shock bracket. You'll have four of these in the kit and they are gonna be specific to a certain location. So we've got them set out here for the axle. So this is going to be for the front axle towards the front. We want this bracket to be angled down towards our equalizer here. And we also want to make sure that the holes are flat facing towards the center of our trailer like that. And the one for the axle behind this is gonna face like this. So these brackets are gonna be angled like this, on the opposite side of our trailer we want the same story to be mimicked over there. So we'll take our bracket now we'll set it on top of our leaf spring you see there's alignment pin there that does line up with the hole in the bracket. We can then set our factory bracket right back on top grab our new U bolts. We'll go up through the bottom through our shock bracket and our factory one. And then we'll secure it with the new nuts that came included with the U bolts. We'll do the same thing with the other two sets of holes right over on the other side of our leaf spring stack. Once we got them all started we can go back and tighten them down. You do wanna kind of go back and forth to try and tighten them down evenly. So you have roughly the same amount of U bolts sticking up above each night. So now we'll torque our hardware to the specifications found in your instructions. And that completes our look at red lines line of replacement, U bolts..

Customer Satisfaction Score:

Customer Reviews

2-3/8" Round Trailer U-Bolts (Qty 2) - SP01-040

Average Customer Rating:  4.7 out of 5 stars   (115 Customer Reviews)


I purchased these u- bolts to go along with the new 3500lb axle I purchased from etrailer for a 12’ utility trailer. Once installed the trailer tolls better than even when new. I highly recommend etrailer for all trailer needs.


Disappointed that this could be sent out like this. The one package came with one ubolt and three nuts. In undamaged packaging.

Etrailer Expert

Brooke M.


That certainly is disappointing! I will have our customer service team reach out to you about this.


The U bolts are good. Replaced some stock U bolts that were smaller in diameter, so they should last. They’re not plated so they will probably rust. I am using them on a boat trailer.


Perfect fit for my new axel


Perfect fit!


Perfect fit.


Worked great holding the piece together for my jet ski dock!


Bought several parts to repair worn out suspension parts. etrailer didn't have the wet equalizer bolts that I ordered. They failed to notify me that they were out of stock, and were not expected to be delivered to them for another month from the manufacturer. After a week of waiting for notification the parts had shipped, I called etrailer and was informed of the delay. I then cancelled the wet equalizer bolts and had the remaining parts shipped. The order arrived within 4 days. All the parts that I didn't cancel were of satisfactory quality, and fit as they sholud have.


Order process was easy and delivered on time.


I rebuilt a 4 wheel trailer, brakes, hubs and one axle repair. All the parts I purchased fit as promised. After a year I have had no problems. Thanks


This one is kind of easy but the products are as described, all parts are present and shipped fast. Good attention to detail like a light coat of oil to keep the parts from rusting while in transit. Heavy made part at a good price, I can fabricate parts but at these prices it's not worth my time and much easier to buy from companies like etrailer.


good quality replacement u bolts and nuts. (note you need to replace once the nuts have been removed because these have special treads that lock in the nuts)


the product was for a Utility Trailer, both springs and U-bolts came well packed, the transaction online was flawless but, the 3 day delivery became a 4 day due to UPS being a little less then honest on the reason for the delayed delivery. I was up until 10pm putting the springs on for an upcoming vacation.
Cathy in customer service was helpful trying to resolve with UPS but dealing with a large delivery service is difficult.
Advice is while you can trust this vendor, trusting for prompt delivery can be iffy.


Good price, fit right. Had everything I needed to help me make my trailer safe again. Shawn worked with my two orders and linked them to get the free shipping.


Excellent product at a fair price with really fast shipping. But the best thing is the attention to customer satisfaction demonstrated by the folks at They are truly focused on the customer!!!!


Heavy duty 1/2" u-bolts. Helped with axle over to axle under swap with extra length in threads to spare.


Very prompt, courteous and professiona l.


This company is a model as to how business should be done. From price to delivery and follow up communication it doesn't get much better. Now if we could just get more parts made in the USA I would really be happy, happy, happy.


Fit good, quality u bolts will use e trailer again


Great replacement for the old rusted on es!


fit perfectly


Parts fit well, I have use ETrailer in the past, they always deliver.


They always get it right or make it right.Great products


They had what I wanted, perfect fit and excellent 2-day delivery.

Thank you, E-Trailer


WEll made, dimensionally correct, very good rolled threads. Nice that the nuts were flanged. Overall, great quality item.

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