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U-Bolt Kit for Mounting 5,200-lb to 7,000-lb, Round Trailer Axles - 7" Long U-Bolts

U-Bolt Kit for Mounting 5,200-lb to 7,000-lb, Round Trailer Axles - 7" Long U-Bolts

Part Number: APUBR-8
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Mount your round, 3" 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 suspension parts from Dexter. U-Bolt Kit for Mounting 5,200-lb to 7,000-lb, Round Trailer Axles - 7" Long U-Bolts part number APUBR-8 can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (339)
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  • Videos (1)
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Dexter Trailer Suspension Parts - APUBR-8

  • U-Bolt Kits
  • Camper
  • Car Hauler
  • Utility Trailer
  • Round Axle - 3 Inch
  • 7 Inch Long
  • 5200 lbs - 7000 lbs
  • 1/2 Inch Diameter
  • Dexter

Mount your round, 3" 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) 7" Long U-bolts (1755892)
    • (2) U-Bolt plates for 1-3/4" or 2" springs (117521)
    • (8) 1/2"-20 Hex nuts (12N)
  • Spring seats required for mounting axle to leaf spring sold separately


  • Axle diameter: 3"
    • Typical 5,200-lb to 7,000-lb axle
  • Spring width: 1-3/4"
  • Thread dimensions: 2" long x 1/2"-20
  • Dimensions: see below

U-Bolt Diagram

K71-732-00 U-Bolt Kit for 5,200-lb to 7,000-lb Round Trailer Axles

Replaces APUBR-8

Video of U-Bolt Kit for Mounting 5,200-lb to 7,000-lb, Round Trailer Axles - 7" Long U-Bolts

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

Video Transcript for Review of Dexter Trailer Leaf Spring Suspension - U Bolt Kit 5200 7000 lb Round Axle - APUBR-8

Hi, everybody, Andy here with Let's take a look together at this Dexter U-Bolt Kit for mounting 5,200 to 7,000-pound round trailer axles. Now this kit is designed to fit axle diameters of three inches, which is going to be your typical 5,200 to 7,000-pound axles. And this kit includes everything that you see here on my table before me. You're going to receive four seven-inch long U-bolts and then two U-bolt plates for 1 3/4-inch or two-inch springs, and then eight 1/2 inch by 20 nuts. And the spring seats.

Spring seats are required for mounting the axle to the leaf springs, and those are gonna be sold separately from this kit. Now, if we measure from the inside of the U-bolt to the bottom of the bolt post, that's gonna give us our seven-inch measurement. And these are tapered where the axle sits to help the U-bolt stay in place on your axle. And the area between the bolt post measure three inches. So that's where we are...

That's where we get the spring width fitting from. And then the diameter of each one of these bolts measure half an inch. And of course, the plates that are included are designed to fit these U-bolts. Well, that's gonna wrap up our look today. I do hope that it was helpful for you.

Again, my name is Andy, thank you for joining me.

Customer Satisfaction Score:

Customer Reviews

U-Bolt Kit for Mounting 5,200-lb to 7,000-lb, Round Trailer Axles - 7" Long U-Bolts - APUBR-8

Average Customer Rating:  4.8 out of 5 stars   (339 Customer Reviews)

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


I upgraded my leaf springs to 4000lbs springs and needed longer axle U bolts and Quinn at etrailer was helpful getting the correct bolts headed my way.


These seem to be working ok but do not appear to be designed for use with the HD upgraded Moryde greaseable shackle kit that I purchased with them . You can see in the photos that they rub and bind

Etrailer Expert

Jenny N.


I do have two recommendations for you. The first would be to make sure that the bolts are not over tightened. The locknuts should only be tight enough to limit as much movement as possible without binding anything up. The second recommendation is that Lippert makes that can be used with the Equa-Flex system. It is part # LC64FR. The shackle straps are less thick at 0.212 thickness however they are longer at 3 and one quarter inches.


Arrived early in excellent condition. Exact fit for what I needed. Have ordered several items from Etrailer over the years without an issue. Great products and company to do business with


Excellent product, I used it to beef up the suspension on my welding trailer. It has proven to be a great quality product. Even though local stores carry this kit, I trust a company with the word trailer in its name, and for good reason. I recommend your website to all of my welding students, so if you're ever in the mood to send parts for me to install, test, and review. Please keep me in mind. I'm currently searching for a good 10" electric brake assembly to replace my existing set, and I'm sure I will be reaching out to etrailer for their expertise.


The u-bolts fit and worked perfectly. I didn’t use the included tie plates, my travel trailer has shock absorbers that attach to the tie plates, I reused the originals. I torqued them to 70 ft. lbs. per Dexter axle specifications. I did clean and paint them before installing. I upgraded my 5400 lb. 4-leaf springs to 6000 lb. 5-leaf springs, which required longer u-bolts.


Item showed up not damaged and install was a breeze, I have ordered numerous items from this web site and my only complaint is they are normally very prompt about getting product in the mail and this time it was 3 days. Not that big of a deal I will still use website for ordering products

by: 06/24/2024

Great service


these u bolts and brackets arrived quickly, installed flawlessly, and seemed to be heavy duty.
i couldn't be happier.


Just installed them a few minutes ago. Great product. I liked the extra ribs in the bottom mounting plates. It seemed to add a great deal of strength. I thought the shipping was a little steep but all in all a good experience. Thank you.


Wow! I have ordered from etrailer for years. Great products. I ordered this on a Tuesday and received it Thursday and shipping was Free!
Painting them now to match trailer and installing them tomorrow. All within a week. Like I said, Wow!


Went together well.


Working great. Still doing well after a year of full time travel on a 5th wheel RV.


Quality product. Works perfectly on my 1968 Plymouth leaf springs.


Everything fit together perfectly. Had a few more nuts in the box than I needed but that is better than being short! :-)


A+ works great. Fast shipping if I ever need axle again will buy from you


I will always order my trailer parts from this company they were quality and reliable I've had a lot of cars using their equipment and parts keep up the good work


I like the fitment of them. The ease of nutting the u bolt was great. The serrated flange nuts probably won't back off, but I like overkill. I will double nut then due to I think road vibration will loosen them.



After a year it works flawlessly as expected.


Have not installed them yet but they look very good. Heavy duty as expected. One u-bolt is a bit twisted fresh out of the box but it should be easy to correct using a vise. Only one of the 8 I bought was this way. Must have slipped past quality control at the factory. It will not affect its integrity or usage.

Dave L.


The kit is working great. No problems with it. Many thousands of miles since the install.


I pull a toy-hauler 5th wheel trailer between Alaska and the lower 48 through Canada twice a year. Much of the road is rough and caused me to break a leaf spring every trip. Since installing a shock absorber system and upgrading from 5-leaf to 6-leaf springs, I have so far eliminated suspension damages on the route.


Excellent people to work with.
I received
what I ordered, and in two business days.

Only problem, was I ordered the wrong size leaf springs and U-bolts.
But, returned them, no problems. Full refund, minus return shipping.
Also, re-ordered. Hopefully, the correct size, this time. (I was three hours away from my trailer the first time I ordered)

Robert H.


Second time was a charm! Good product. Fit perfectly. Thank you!


I think you screwed up. I did not receive the U bolt kit, I received Part # CT-3000-RK, Repair kit for 2" straight coupler which I did not order. I reported this upon delivery of the wrong part.

Etrailer Expert

Jenny N.


We recently sent you a new u bolt kit and were wondering if you had any feedback about the product for other shoppers? We look forward to hearing from you.


Nice Robust suspension parts. I'm however using these for Ham radio antenna Mounts, as i can't find u bolts in this size in the Ham world... Cheers..


Etrailer made it easy and quick to order the missing parts from two axles that I bought online.


Wanted to switch to five leaf springs from 4 leaf on my dual axle 27 ft. trailer. Prices were better than I could get in Calif. with addition of free shipping. Parts arrived in three business days, I was surprised at promptness. Staff very helpful after I got my measurements figured out, as old springs were stretched 3/8 inch. Shocks arrived just after I had the springs all installed. Parts were great, only thing I would have liked better was a small instruction sheet on torqueing bolts. Would recommend etrailer to my friends.


Just what I needed to complete my stock trailer repairs

Show More Reviews

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  • How to Determine Correct U-Bolt Kit and Leaf Spring Bushing for a 6,000 Lb Trailer Axle
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