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Redline

2" Square Trailer U-Bolt (Qty 2)

Part Number: SP01-160

705 Reviews | 33 Questions

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redline trailer suspension parts u-bolts square axle - 2 inch u-bolt (qty 2)

redline trailer suspension parts square axle - 2 inch 5-3/4 long sp01-160

redline trailer suspension parts u-bolts 5-3/4 inch long 2 square u-bolt (qty 2)

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Feature Review 2" Square Trailer U-Bolt (Qty 2)

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Square Trailer U-Bolts Great Prices for the best trailer suspension parts from Redline. 2" Square Trailer U-Bolt (Qty 2) part number SP01-160 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.

Redline Trailer Suspension Parts - SP01-160

Square Trailer U-Bolts

Features:

2" Wide
9/16" Diameter
5-3/4" Long
Length of threaded section: 2-1/2"
Inner width: 2-1/8"
Includes nuts

SP01-160 2" Square Trailer U-Bolt (Qty 2)

Video of 2" Square Trailer U-Bolt (Qty 2)

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

Video Demo Redline Trailer Suspension SP01 160

Feature Review 2" Square Trailer U-Bolt (Qty 2)

Video Transcript for Feature Review 2" Square Trailer U-Bolt (Qty 2)

Today we are reviewing SP01160. This is a set of two 2-inch square trailer U-bolts and they are used with U-bolt plates for 2-inch square axles. Those are sold separately as part number 117594 and that plate, along with these U-bolts will secure the trailer axle to the leaf springs and those are mounted to the trailer frame. So, what you have here are two 9/16th inch diameter bolts that are, here we go, 5-3/4 inches long. The threaded portion right here, as you can see, is 2-1/2 inches long and the diameter, inside-to-inside here, is 2 inches. These bolts do come with the nuts that you will need and that is it for Part Number SP01160 from Redline, 2-inchSquare Trailer U-Bolts.

Customer Satisfaction Score:

97% were satisfied with this product

3% of customers were not satisfied

Product did not meet expectations
Wrong item was ordered
etrailer mistake

3% of customers were not satisfied

Product did not meet expectations
Wrong item was ordered
etrailer mistake

4.8

705 reviews

5 Stars		(605)
4 Stars		(66)
3 Stars		(19)
2 Stars		(5)
1 Star		(10)

by: Joe V. 06/11/2013

Great Experience!

When I noticed that the leaf springs on my 44 year old boat
trailer had cracked I thought I would never find replacements.
I fully expected to have to have something custom built.

I was amazed when I found the fantastic diagrams/descriptions
dimensions for replacement springs on etrailer.com

The phone support person was wonderfully helpful in confirming
if items were in stock and ready to ship. The replacement springs
arrived on time and everything bolted up perfectly!

Thanks for such a great site!

Click to Enlarge

by: David P. 11/14/2013

Worked great fit was good.
I did not use standard nuts furnished but used Nylon lock nuts instead.

Click to Enlarge

David P. One Year Later

11/14/2014

No problems....still like it and still going strong on my boat trailer!

by: Jose 03/26/2026

Perfect fit with my other purchase and perfect for the repair job on my old trailer.

by: Jeff B 10/08/2011

I used this to bolt down all four supports that had begun to crack at the welds. I was concerned that welding would cause the galvanized steel to rust so I found this solution. The heavy construction of this part is very strong and should do the trick. Installation was very easy and quick.

Click to Enlarge

by: Stephen 02/07/2026

U bolts are perfect. Set should have come with flat washers , or washer head nuts

by: Juan 05/20/2025

Well, these u-bolts are u-bolts. They're for my dual axle cargo trailer. They're 9/16" diameter. If you're familiar with these measurements and familiar with non commercial trailers, these are heavy duty hardware. And what I received, is what I expect. After carefully looking at what I needed and then looking at etrailer's website, I ordered these parts. They worked perfectly. I tightened them without reservation. They're holding. In my opinion, this took a little long to ship out to me, but otherwise, a good product.

by: chuck finley 11/05/2016

my friend ordered springs and hardware for my pontoon trailer. man did they get here fast. everything in one box. packed real good. no damage, nothing lost or left out. I finally got everything back together. fits great. i was worried that the springs where going to be to light, but the trailer sits just like new. sorry no pics. I was to greasy to get the camera out. But its like new again. yes etrailer.com i'm gonna be back next time I need parts. and i've already told all my friends with boats and trailers about etrailer.com . I am a happy customer. thanks again. C Finley

Chuck F. One Year Later

11/15/2017

Thanks for your follow up. Parts are still doing fine. I am still veryhappy with my shopping exp. With etrailer, and I have had the opportunityto share my exp with several people hope they come shopping with you.

Chuck F. One Year Later

11/15/2017

Thanks for your follow up. Parts are still doing fine. I am still very happy with my shopping exp. With etrailer, and I have had the opportunity to share my exp with several people hope they come shopping with you.

by: John W. 01/21/2016

These appear to be standard black steel and are of sufficient length to mount springs on top of axle or go with under slung arrangement. The nuts are crimped lock nut style which is ok.

John W. One Year Later

1/21/2017

No problems after one year of hard usage and heavy loads.

by: Tom 07/21/2025

Always arrives quickly. I did add lock washers.

by: William J. 08/07/2015

The SP01-160 square u-bolts were perfect for my project. I had to have a certain size dia bolt and length, and these were just what I needed. I located some where I live, but they were very expensive. Found these at Etrailer and their price were half the price what they wanted here. I talked and ordered from Pat and she was very helpful on my order. The shipment was very fast also, ordered on Tuesday and received on Friday. I will definitely order from Etrailer again......Pat, thanks again

William J. One Year Later

8/6/2016

Worked out perfect very sayisified

by: Tenebs 11/27/2023 One Year Later

Had a leaf spring break on my off-road trailer in Mexico. Left it at a boat yard until I received the parts from trailer & returned to replace. Only took 2 hrs to replace both leafsprinhs, shackles, bolts etc. And we were back on the road.

by: Shelia 06/05/2019

SP01-160 U Bolts look to be good quality just wish they came with lock washers.
TRTP200175 U Bolt spring plates work well with these U Bolts. I ordered 4 of these and got 1 and 3 #117594 plates which are very nice and look more heavy duty.
I thought I got stiffed with the one oddball one but I didn't I ordered the cheaper ones and got 3 of the heaver duty ones.
I also ordered #LC281285 Never Fail Tandem Axle Suspension Hardware Kit and one bolt in the kit is to long like its for a 2" wide spring. Guess I will just use one of the old ones I took out.
And 4 #SP-051275 4 leaf double eye leaf springs.
I am redoing the suspension on a fiber splicing trailer that was damaged during hurricane Michael.
All in All etrailer has great prices and fast shipping and great customer service.

by: Dave H. 03/13/2019 One Year Later

Very heavy duty steel and worked for my application. Sadly they are not galvanized; hence the 4 star rating. I prepped, primed, and painted them well so they should hold up. Used to hang fenders on a boat trailer.

by: Nick 06/05/2017

Quality is excellent,I wish I had ordered lock nuts and washers as the u bolts just come with standard nuts.I will just use lock tight and check for loose nuts until they get rusty.If you need trailer parts I have ordered every thing from bearings and races to suspension bushings and spare tire covers from etrailer and have not been disappointed with any thing.

by: Christian 04/27/2018

Products are as advertised and of excellent quality. Prompt shipping and professional. No fuss, no muss... what more could I ask for!

Christian One Year Later

4/27/2019

Still on my boat trailer no issues!

by: Christian 04/27/2018

Products are as advertised and of excellent quality. Prompt shipping and professional. No fuss, no muss... what more could I ask for!

Christian One Year Later

4/27/2019

Still on my boat trailer no issues!

by: Doug 04/30/2020

The product was excatly what i thought it would be. The description of the product was spot on. However, the tracking system is poor, almost sophisticated enough for a three year old. Believe me you will want to track your package. If you do not so much time will pass that you may forget you ordered anything. It is possible "the virus" played a part ..... nope! this was real.

by: Tommy H. 03/24/2014

Bought everything to completly rebuild my trailer. All products were good quaility and fit perfectly. The outstanding service was the best part. Never have done trailer work before and I called and talked to support. Got me everything I needed and it was all correct. Upgraded my shipping for free and I still recieved my order quicker than they told me I would.

by: Sarah M. 12/16/2016

I have a huge old miley horse trailer that has seen better days and all of the leaf springs, bearings, etc needed to be replaced, It wasnt like I could go into a name brand parts store to get them either. So when my husband told me he found everything he needed on etrailer.com, I was relieved. I am very happy with the price and the delivery time. The fact that delivery was free was definitely a bonus because the parts were very heavy. I was a little worried about the condition of the parts when they came, the boxes were pretty beat up (very heavy) but so far I haven't found any problems.

by: Pg 11/11/2015

Etrailer offers galvanized spring plates but in the U bolts, un protected steel bolts and nuts. Makes no sense to have a mixture of galvanized and unprotected parts in the whole assembly!

I bought a can of galvanized spray paint at Home Depot to coat the raw metal parts.

by: Ed R 09/17/2016

Erika was super helpful. Really helped me get the correct parts the first time. I will always use etrailer from now on!!

A+++ in my book!

Ed R. One Year Later

9/17/2017

SUPERB!!!!!!!! Erika at E-Trailer is AWESOME!!!!

by: Austin M 01/21/2016

Good thick U bolts, you can get away with about 1.5" of drop using a spacer block in between the spring and the axle. I was planning on 2" of drop but these U bolts are too short. That is my only complaint, and it is my own fault. I didnt know how thick the leaf springs were going to be so I thought these would be long enough, but not with 3500 lb 4 leaf springs.

by: John P ( Colfax NC ) 09/17/2014

Was able to ONE Stop Shop
Free Shipping exceeded Order total required
Located all Parts easily required to rebuild Trailer Suspension
One Order and Done ... all from Comfort of Home
Delivery was on time as all my previous Orders
Many thanks for being a Online WEB Provider Leader

by: Rich M 10/27/2016 One Year Later

Great product, as described, description of the measurements fit right on.
I would & have recommend E-trailer to friends.

Rich M. One Year Later

10/27/2017

Fit and works as described, Im happy with the product.

by: Edw S. 07/31/2021

etrailer was and continues to be a great business that provides quality products as timely to its customers as is reasonably possible. I appreciate etrailer's perpetually prompt attention to my trailer needs. I replaced the axle in my classic '67 Cardinal Travel Trailer and was surprised to learn I had been given some poor advise. I reordered through etrailer as I needed the parts promptly and did receive the items "timely" as requested. More importantly, they are the correct parts! I appreciate etrailer's parts & prompt service....Thank you sincerely!

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See what our Experts say about this Redline Trailer Suspension Parts

Do you have a question about this Trailer Suspension Part?

Converting a Kayak Trailer w/ Bunks to Crossbars
Hey Tricia, thanks for the pictures. I definitely think that would work. You're not far off from how the Malone EcoLight Sport Trailer item # MAL43FR is setup with what you're describing. Are the bolt holes on the uprights spaced 2-1/2" apart? Our 2" Square U-Bolts item # SP01-160 fit bolt holes spaced 2-5/8" apart and require a hole 9/16" in diameter. These are designed for 2" square axles so they'll definitely lock down a set of square bars like the 79" Inno item # IN436L you were looking...
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Will The 117594 U-Bolt Plate And SP01-160 U-Bolts Work With TRU62FR Springs On A 2 Inch Square Axle?
Hello Russ, Welcome to etrailer, I'm glad you found us! Yes, those parts are compatible with each other for a 2" square 3,500 lb axle. The U-Bolt Plate # 117594 is specifically designed for a 2" square axle with 1-3/4" or 2" wide leaf springs and uses 9/16" diameter U-bolts. The # SP01-160 U-bolts are made for a 2" square 3,500 lb axle, are 9/16" in diameter, and are specifically listed for use with the # 117594 plate. Your # TRU62FR springs are 1-3/4" wide and rated for 1,750 lbs each,...
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Replacement Leaf Springs, Shackles, and Equalizer for a Tandem Axle Boat Trailer
Hey Kyle it sounds like your leaf springs are too long. How did you measure them to get 28-1/4" long? We recommend lifting up the side of your trailer and getting the weight off of the suspension then measuring the leaf springs from eye to eye. The older springs are the farther they stretch and this sounds like what you're dealing with. I would need to know how long your springs are from eye to eye, the capacity of your axles, and the amount of leafs to recommend the correct replacement....
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Longest 2-Inch Wide Square U-Bolts
Hi Steven, I'm sorry to say we do not have 2 inch wide square U-bolts that are 8 or 9 inches long; the longest 2 inch wide square U-bolts are the 5-3/4 inch long 2" Square Trailer U-Bolts # SP01-160.
view full answer...
Switching from Slipper to Double Eye Leaf Springs on EZ Loader Trailer
In order to switch from slipper to double eye springs you'll need new hangers which are going to dictate your height so if you're looking to maintain the same height, you'd want to choose new hangers which are the same height as your existing. The Single-Axle Trailer Hanger Kit for Double-Eye Springs part # APS2 is a good option with 1-1/2" front and 1-1/4" rear. It can then be paired with the 4-Leaf Double-Eye Spring for 4,000-lb Trailer Axles part # e48SR. I also recommend replacing the...
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Correct Replacement for 26-1/2 Long Leaf Spring
It's not uncommon for new trailer leaf springs to measure shorter than the old leaf springs they are replacing. The reason for this is that leaf springs stretch as they age. Therefore, I do think the 26" long leaf spring options we offer will work for you. In order to find the right one you just need to find your axle capacity; part # e77SR for 2,000 lb, part # e22YR for 4,000 lb, or part # e94SR for 6,000 lb. For new u-bolts, we have the 2" Square Trailer U-Bolt part # SP01-160.
view full answer...
Replacement Trailer Suspension Parts for Trailer with 2 Square Axle
It looks like you've got a pretty good grasp on all of this and thank you for the detailed information; it looks like most of the parts you've mentioned will work for you. For the leaf springs, the 26" long # e27SR will be the best option for you since springs stretch out over time and they're right around the capacity of what the axles likely is. The next closest size would be the 25-1/8" # e54SR, but I would be hard pressed to believe that your old ones have stretched out over a full...
view full answer...
Replacement U-Bolts For A 3,500lb Axle On A 2020 Grand Design Imagine 22MLE XLS
Since your axles are round it's actually best to measure with a set of calipers # PTW80157 instead of a tape measure, as you have to kind of eyeball and guess what the actual measurement is. Based on the picture you provided I can see you're under 3" so you would have a 2-3/8" axle unless you had some homemade axle, but I'm assuming with the age of the trailer that you're the original owner from the factory so that wouldn't be the case. For 2-3/8" axles you'll need the CE Smith U-Bolt...
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How To Choose The Correct Leaf Spring U-Bolt Diameter Size On A Trailer Axle
You will want to choose the diameter size of U-Bolts you need by the axle type (round, square) and the axle diameter. The Redline 2 Inch Square Trailer U-Bolt, part # SP01-160, you have referenced is for a 2 inch square axle. It is a 9/16 inch diameter bolt. The 9/16 inch diameter U-Bolts are used on 1-3/4 inch and 2 inch square axles, 2-1/2 inch round axles, 3 inch round axles, and 3-1/2 inch round axles. I am including a link to a page of the available 9/16 inch diameter U-Bolts. The...
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Can Round U-Bolts Be Used On a Square Axle Tube?
You need to use square U-Bolts with having a square axle tube. Trying to use round U-Bolts you risk damaging both the bolts and the axle as it creates pressure points rather than distributing the load across the surface. We have a few different size bolts you can see in the list below. 1-1/2" U-Bolts # SP01-120 1-3/4" U-Bolt # 175130 2" U-Bolts # SP01-160
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Parts Needed For An Over-Under Suspension Conversion On A Boat Trailer
Hey Travis, Since you have a square tube axle the Dexter over-under conversion kits aren't going to have the correct spring seats. We don't currently offer square tube spring seats so you'll need to source them somewhere else and then have a qualified welder weld the new spring seats on the bottom of the axle at the same spot as the originals. You'll want to measure the axle to make sure you're getting the correct size. From there you'll just want to replace the u-bolts because as they...
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Replacement U-Bolt and Plate for Trailer with 2 Inch Square Axle
For a 2 inch square axle you are going to want u-bolt plate # TRTP200175. The hole spacing on center is 2-5/8 inches by 2-3/8 inches. For matching u-bolts go with # SP01-160. They have a 9/16 inch diameter. I have included a link to a video review for you for the u-bolts.
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Recommended Torque Specifications for U-Bolt # SP01-160 in a Slipper Springs Trailer Setup
Since the # SP01-160 u-bolts are 9/16 inches in diameter the torque rating is from 65 ft/lbs - 95 ft/lbs. I have linked a Help Article on Slipper Spring Trailer Suspension System Review to this page that lines out the torque ratings of the different diameter u-bolts for you to check out. I linked all the parts you mentioned to this page for your purchasing convenience.
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U Bolts for a 3,500 lbs Square Axle
I have a solution for you but we do not have a 2" square u bolt kit for a 3,500 lbs square axle that is 5 3/4" long. You will need to buy the u bolts and u bolt plates separately. The Square Trailer U-Bolt item # SP01-160 comes in a 2 pack, is 2" wide, 9/16" diameter, 5-3/4" long, and has a 2 1/2" length of threads. The U-Bolt Plate for 2" Square Axle item # 117594 comes single and works with 9/16" u bolts.
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U-Bolts to Attach Bunk Brackets to Trailer with 3 inch Frame
For a 3 inch trailer frame like you said you have we have the U-bolts part # 7163183UB which will work great for attaching roller bunk brackets like the part # CE10000G-4. The inside portion of the U-bolt is 3-1/8 inches wide by 3 inches long.
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Using Nylon Lock Nuts On 2 Inch Square Trailer U-Bolt SP01-160
For the 2 inch Square Trailer U-Bolt, part # SP01-160 you purchased, you can use nylon lock nuts that would work for a 9/16 bolt.You would want to make sure you use nuts of equal strength and that they match the thread and size.
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Replacement Leaf Springs and U-Bolts for a 1987 Shore Line Boat Trailer
Thank you for submitting the photo of your setup. Considering the height of your axle and the amount of clearance you currently have from the axle to the frame of your trailer you wouldn't have enough room to put your axle above the leaf spring. You would barely have a couple of inches of suspension travel. For U-bolts you would want the part # SP01-160 and then for plates you would want the # 117594. Based on the dimensions of your current slipper springs the # SP-040275 that you referenced...
view full answer...
Replacement U-Bolt Plate for a Trailer with 2 Inch Square Axle
For a 2 inch square axle you are going to want u-bolt plate # TRTP200175. The hole spacing on center is 2-5/8 inches by 2-3/8 inches. For matching u-bolts go with # SP01-160. They have a 9/16 inch diameter. I have included a link to a video review for you for the u-bolts. It does sound like you will need to replace some existing components if they do not match up. I do not recommend modifying anything because that can weaken those items. Any welding should be performed by a qualified professiona...
view full answer...
U-bolts for Gooseneck Trailer hitch Safety Chains
U-bolts for gooseneck hitches have springs on them so that the retract down when not in use. U-bolt kit # C113 sounds like it would work for you with the measurements you have provided. The u-bolts are 2 inches wide on center and the springs, washers, and nuts are included.
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How to Pick Out Replacement Slipper Springs for a Boat Trailer with 2 inch Square Axles
In order to pick out springs you need to remove the load on the trailer so that the leaf spring is not flattened out at all. You will want to measure from the center of the eye of the spring to the center of where the slipper spring contacts the hanger. If that distance is 26-1/4 inches and the capacity of the axle is 4,100 lbs the # e33SR would fit and work well. The bushing of this spring is 9/16 inch in diameter. You will want to use a 9/16 inch diameter bolt so you can either premeasure...
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Are 5-3/4 Inch U-Bolts Long Enough for a 3 Inch Tall Axle and Slipper Spring # SP-040275
The internal length of u-bolts # SP01-160 is 5-3/4 inches so you would not subtract 9/16 inches from that length. The u-bolt plate # 117594-G is 3/16 inches thick. The spring stack for # SP-040275 I just measured and it is 1-7/16 inches thick. Adding in the 3 inch height of the axle and the total comes to 4-5/8 inches. So all of these parts will fit your trailer axle.
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What Type of Thread Does 2" Square Trailer U-Bolt Have
The 2" Square Trailer U-Bolt # SP01-160 has fine threads (SAE) so it is 9/16"-18 or 18 threads per inch. This comes with 2 U-bolts and includes the nuts required for installation.
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Are The Threads on the 2" Square Trailer U-Bolt # SP01-160 Cut or Rolled and Can They Be Cut Deeper?
The threads on the 2" Square Trailer U-Bolt # SP01-160 are rolled. We do not recommend attempting to cut the threads any deeper on the bolt. You can use a spacer to help make up for the difference if you are not able to find another U-Bolt with the deeper threads you are needing.
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Does the Replacement U-Bolt for 2 Wide, Square Axles Come With Nuts
The Replacement U-Bolt for 2" Wide, Square Axles part # UBZC716X212X400 does not come with nuts. The bolts are 7/16"-14 so you can pick up nuts for them at any local hardware store. We do however offer a similar u-bolt in a kit which does come with nuts, the 2" Square Trailer U-Bolt Kit part # SP01-160. These u-bolts are slightly longer.
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