1. Trailer Leaf Spring Suspension
  2. Redline
  3. U-Bolts
  4. Axle Mounting Hardware
  5. Square Axle - 1-1/2 Inch
  6. 5 Inch Long
1-1/2" Square Trailer U-Bolts (Qty 2)

1-1/2" Square Trailer U-Bolts (Qty 2)

Item # SP01-120
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Our Price: $17.46
Trailer Leaf Spring Suspension
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Shipping Weight: 1.52 lbs
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SP01-120 - 1/2 Inch Diameter Redline Trailer Leaf Spring Suspension
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Lowest Prices for the best trailer leaf spring suspension from Redline. 1-1/2" Square Trailer U-Bolts (Qty 2) part number SP01-120 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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  • Reviews (75)
  • Q & A (12)
  • Videos (1)
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Redline Trailer Leaf Spring Suspension - SP01-120

  • U-Bolts
  • Axle Mounting Hardware
  • Square Axle - 1-1/2 Inch
  • 5 Inch Long
  • 3500 lbs
  • 1/2 Inch Diameter
  • Redline


Square Trailer U-Bolt

  • Width: 1-1/2"
  • Diameter: 1/2"
  • Length: 5"
    • Threaded portion measures 2"
  • For 3,500-lb axles only
  • Includes Lock Nuts

071090 Redline Square Trailer U-Bolts with Nuts and Washers





Video of 1-1/2" Square 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 Redline Trailer Suspension SP01-120 Review

Today we'll be reviewing part number SP01-120. This is Red Line's 1 1/2 inch Square Trailer U-bolts. You're going to get two U-Bolts and you're going to get four nuts. The width of the U-bolts. We're measuring the distance between the two bolt posts. Is going to measure an inch and a half.

Each bolt is going to give us a diameter of a half inch. The length that we have from the bottom of the cross member to the bottom of the mounting post or the bolt post is going to be 5 inches. The threaded portion going to measure right at 2 inches. This is for 3500 pound axles 00:43 only. Again, you're going to get two U-bolts, measure a half inch in diameter, and you're going to get four nuts.

That's going to do it for our review of part number SP01-120. This is Red Line's 1 1/2 inch Square Trailer U-bolts. .


Customer Reviews

1-1/2" Square Trailer U-Bolts (Qty 2) - SP01-120

Average Customer Rating:  4.8 out of 5 stars   (75 Customer Reviews)


- SP01-120
by:

hard to find item, only wish they were galvanized. seems that nobody makes a galvanized 1 1/2 in. square u-bolt. but product shipped very fast, and in good condition. thanks 716823



- SP01-120
by:

100% impressed with etrailer. My customer rep, Diana, was very courteous, knowledgeable, and friendly. I placed my order on Monday and was told that my shipment would arrive on Thursday. About ten minutes later, I received an email stating that my order had shipped! I just received another email that my package has been delivered - a day early. I was able to track the package from the etrailer website. I just want to say thank you for the unexpected, exceptional service from everyone at etrailer. I look forward to placing more orders in the near future. Thanks again 716353



- SP01-120
by:

Product was very easy to install, very well built and looks good on my trailer 656047



- SP01-120
by:

I purchased these U bolts to upgrade the suspension on my trailer. I would get a a lot of trailer sway when I was towing my jet ski trailer. I bought the trailer used and never really looked at the springs. Unfortunately for me, There was nothing but one U bolt strapped diagonally across the spring. I'm no suspension expert but I knew this could NOT be safe. I did extensive research on trailer suspension. It was difficult to find parts for a 11/2 inch square axle. It was until I came across etrailer webpage. They had everything I required to upgrade and make my trailer safe to operate on the road. It was actually criminal what the person did to attach the original spring. I am greatful nothing ever happened while towing. Now with the new parts installed, I feel a lot better and my trailer does not sway anymore. I will definitely purchase my trailer needs from etrailer from now on. The pictures and videos make finding what I needed so much easier. The complete transaction from order to delivery was extremely efficient and the customer service is absolutely outstanding. 636959



- SP01-120
by:

Appear to be very strong! They do NOT come plated and ready to use! They have to be degreased, primed and painted (or powder coated?) for maximum rust prevention! 628292



- SP01-120
by:

Perfect fitting ubolts for new axle installation, no issue's after a year of heavy use. 621944



- SP01-120
by:

Good quality, perfect replacement after cutting my old rusted u-bolts off. 621577



- SP01-120
by:

Thank u very much 578975



- SP01-120
by:

Excellent product and I appreciate the quick shipping I was not expecting. 564162



- SP01-120
by:

Bought these a year ago and still in like new condition, no rust at all and was a perfect fit when installed 544166



- SP01-120
by:

The U bolts and spring plates were of good quality, but the price was much higher than it should be. I needed them so I bought them, even though the price was way too high. 528841


Comments
Good
Landy - 06/30/2019

57313

- SP01-120
by:

These are exactly what we were looking for. etrailer is the only place we could find the 1.5" Size in a 1/2" diameter square u-bolt. 514237



- SP01-120
by:

They were ok , they hold the bracket on that hold the fender on. 510027



- SP01-120
by:

Only place that had the part i needed. Called to make sure it was the right part and ordered over the phone. Fast and easy. 506028



- SP01-120
by:

Perfect fit. Everything went together very smoothly. 505813


Comments
great, no problems with about 1000 miles on the new parts now.
Michael E - 05/10/2019

55082

- SP01-120
by:

Products are as advertised and of excellent quality. Prompt shipping and professional. No fuss, no muss... what more could I ask for! 501221


Comments
Still on my boat trailer no issues!
Christian - 04/27/2019

54558

- SP01-120
by:

These U-bolts were hard to find any where else. As always, etrailer came thru. The U-bolts went perfect with the plate that I also ordered from etrailer. The part went on with ease on my old Gamefisher trailer. Road tested it today and its holding good and no problems. Everything that I have ordered from etrailer has a very good price and great inventory that no one can match. 482657


Comments
Its been a year since I put this on my trailer and its working great. No problems at all. Thanks etrailer for having hard to find parts and great service.
Robert - 03/08/2019

50309

- SP01-120
by:

They are working very well. 475410



- SP01-120
by:

exactly what I wanted & worked like it was intended 462117



- SP01-120
by:

I used these u bolts on a harbor freight folding trailer. I wanted to lift the trailer to put larger tires. After welding blocks on, these u bolts fit perfect. 423363



- SP01-120
by:

They fit perfectly! 378463



- SP01-120
by:

The most difficult part was tightening the nuts to the point that the head of the shackle bolt was flush against the shackles and hangers. Afterward, I loosened the nuts a little. But, I don't know how much to loosen them. 377848



- SP01-120
by:

very good products and excellent customer support. 369502



- SP01-120
by:

Great product fast shipping 361011



- SP01-120
by:

Perfect fit 356053


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Show More Reviews

Ask the Experts about this Redline Trailer Leaf Spring Suspension

  • U-Bolts And Mounting Plates For A 1-1/2" Square Trailer Axle
    After a bit of research, I have determined that item # 49133 is a 1-1/2" square trailer axle. The correct u-bolts and mounting brackets for this axle are the 1-1/2" Square Trailer U-Bolts part # SP01-120 and the U-Bolt Plate for 1-1/2" Square Trailer Axles with 1-3/4" Wide Springs part # 115983. I have attached a video review for both of these products for you.
    view full answer...
  • Length of Threads on 1-1/2 Inch Square Trailer U-Bolts Part # SP01-120
    I pulled one of these from our warehouse and there is 2 inches of threads on the U-Bolts.
    view full answer...
  • Torque Specs for Nuts that Come with 1-1/2" Square Trailer U-Bolts # SP01-120
    Yes, my contact at Redline said the nuts that come with the 1-1/2" Square Trailer U-Bolts # SP01-120 should be torqued anywhere between 45-75 ft-lbs.
    view full answer...
  • Brackets Needed to Mount Fulton Single Axle Trailer Fenders with Top and Side Steps F008584-2
    You will need 4 of bracket # PF1135-BKT to mount fenders # F008584-2. Because your frame is so narrow you will need to drill a hole in each bracket to accept u-bolts that fit around your frame. We do have some 1-1/2 inch wide, 5 inch long u-bolts you could use, # SP01-120, sold as a pair. You would need 2 pair. If you don't mind drilling into the trailer frame you could also use # PF775-BKT-2 and place them wherever you can on both the fender and the trailer. You would need 2 pairs of...
    view full answer...
  • Need Replacement Square U-Bolt for 1-1/2 Inch Axle
    For a replacement U-Bolt closest to your measurements, I have the Replacement U-Bolt with Nuts, part # 1753223, which is for 1-1/2 inch wide, square axles. We also sell these U-Bolts in a pair, part # SP01-120. The Replacement U-Bolt, part # 1753223, will work great with your 1-1/2 Inch, 1800 pound capacity axle. U-Bolts do not typically carry a weight rating.
    view full answer...
  • Are there Bolt-On Hangers for Trailer Leaf Spring Suspension
    We do have a couple of bolt-on spring hangers # CE14017G and # CE14016G but they are designed for slipper springs and not double-eye springs like # SP-124275. Its not likely that professional welder would charge that much. You might be able to find one locally via an iron workers union near you. For u-bolts for your 1-1/2 inch square axle you can use # SP01-120 for 2 u-bolts and 4 nuts. For a u-bolt plate you can use # 115983. For a hanger kit you could use # APS1. Now what you could...
    view full answer...
  • Replacement U-Bolt Plate and Bolts for 1-1/2 Square Axle
    The smallest square axle U-bolt kit and bolt plate is for 1-1/2 inch axles. For that you would want the part # SP01-120 for the U-bolts and part # 115983 for the plate. You might double check the axle measurements, they might actually be 1-1/2 inch square axles.
    view full answer...
  • How to Determine the Correct Leaf Springs and Parts for Suspension 1956 Shasta Camper
    To determine the correct parts you need to replace the springs on your trailer you will need to do some measuring and find the GVRW, Gross Vehicle Weight Rating, of your trailer. Measure the distance between the center of each eye on your trailers existing springs. The new springs you select should then match 1/2 of the trailer GVWR and the distance of the measurement you take. If you find that the measurement on your springs is 1/2 to 1 inch longer than the measurement of a spring that...
    view full answer...
  • U-Bolts and U-Bolt Plate Recommendation for Installing Leaf Springs on a 1-1/2 in Square Axle
    If what you really need is a new axle you can go to a local trailer shop to you and have them custom order you the exact specs you need for a trailer axle. But to attach springs to your 1-1/2 inch square axle you would want the mount plate part # 115983 and then for U-bolts part # Sp01-120. I attached review videos for both products.
    view full answer...
  • Length of U-Bolts Needed for Trailer Suspension and a 1-1/2 Inch Square Axle
    The typical length of u-bolts for 1-1/2 inch square axles is 5 inches such as # SP01-120. The u-bolt length should not be any different whether the axle is above or below the leaf spring stack unless you go to leaf springs that are taller (more leaves) than the old springs. If you are moving the axle from above the springs to below the springs then since you have a square axle there aren't any special parts needed. The plates you mentioned for each spring should be welded to the axle.
    view full answer...
  • Will 1-3/4 Inch Wide Leaf Springs Fit a U-Bolt Plate for a 1-1/2 Inch Wide Square Axle
    Regardless of the axle diameter, generally most modern double-eye springs are 1-3/4 inches wide. U-bolt plate # 115983 works with u-bolts # SP01-120 which have a 1-1/2 inch width to fit around the axle. The u-bolt plate will set below the the leaf spring stack, the u-bolts will go around the axle and through the u-bolt plate and then bolted on. Take a look at the FAQ on double-eye suspension I have linked for you.
    view full answer...
  • How to Increase Ground Clearance with Slipper Springs.
    I can help you figure out how to get more ground clearance from your trailer. All of our over under kits have only been tested on a double-eye spring setup, these are secured on both ends unlike slipper springs which are not. I would worry that it could become unsafe since the weight of the trailer was pulling on the axle and once you switch the location of it all the weight will now be pushing down on the rectangular axle. While we don't have a specific over under kit for rectangular...
    view full answer...

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




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Info for this part was:

Expert Research:
Patrick B
Expert Research:
Adam R
Video by:
Kathleen M
Installed by:
Cole B

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