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U-Bolt Kit for Mounting 8,000-lb, Round Trailer Axles - 8" Long U-Bolts

U-Bolt Kit for Mounting 8,000-lb, Round Trailer Axles - 8" Long U-Bolts

Item # APUBR-35
Our Price: $64.19
Trailer Suspension Parts
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Mount your round, 3-1/2" 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 Redline. U-Bolt Kit for Mounting 8,000-lb, Round Trailer Axles - 8" Long U-Bolts part number APUBR-35 can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (70)
  • Q & A (0)
  • Videos (1)
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Redline Trailer Suspension Parts - APUBR-35

  • U-Bolt Kits
  • Camper
  • Car Hauler
  • Utility Trailer
  • Round Axle - 3-1/2 Inch
  • 8 Inch Long
  • 8000 lbs
  • 9/16 Inch Diameter
  • Redline

Mount your round, 3-1/2" 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) 8" Long U-bolts (11-65)
    • (2) U-Bolt plates for 1-3/4" or 2" springs (117581)
    • (8) 9/16"-18 Hex nuts (916N)
  • Spring seats required for mounting axle to leaf spring sold separately


  • Axle diameter: 3-1/2"
    • Typical 8,000-lb axle
  • Spring width: 1-3/4" & 2"
  • Dimensions: see below

U-Bolt Diagram

APUBR-35 U-Bolt Kit for 8,000-lb Round Trailer Axles

Video of U-Bolt Kit for Mounting 8,000-lb, Round Trailer Axles - 8" Long U-Bolts

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

Video Transcript for Redline Trailer Suspension - Leaf Spring Suspension - APUBR-35 Review

Speaker 1: Today, we're taking a look at U bolt kit for mounting 8000 pound round trailer axles. This kit attaches a trailer axle to the loose springs. It includes four eight inch long U bolts. That measurement's taken from the bottom of the U portion here out to the end of the threads. Comes with two U bolt plates for 1 and 3/4 inch, or 2 inch springs, and it comes with eight 9/16th inch by 18 hex nuts.Now, spring seats, they're required for mounting the axle to the loose springs. Ours sold separately.

If you need spring seats, you can check some options out at This kit is designed for a typical 8000 pound axle that has a diameter of 3 and 1/2 inches. We're looking at nice, durable steel construction on this kit. And again, it fits springs that have a width of 1 and 3/4 inches and 2 inches. That's going to do it for today's look at the U bolt kit for mounting 8000 pound round trailer axles..

Customer Satisfaction Score:

Customer Reviews

U-Bolt Kit for Mounting 8,000-lb, Round Trailer Axles - 8" Long U-Bolts - APUBR-35

Average Customer Rating:  4.8 out of 5 stars   (70 Customer Reviews)

Mount your round, 3-1/2" diameter axle to your trailer's leaf springs with this U-bolt kit. U-bolts, plates and nuts included.


Everything I have ordered has been correct. Excellent customer service!


The box looked like it was used as a bowling ball. The parts are good except that I am missing 3 nuts that must have fallen out in shipping since the box was so damaged. The parts themselves seem ok.

Etrailer Expert

Jenny N.


Uh oh! Sounds like that box was in rough shape. Customer Service will be in contact to have the nuts shipped out.


Nice job "e-Trailer"; received this "heavy" order very promptly; did not expect it so quickly in view of how other retailers/ manufacturers/ on-line businesses are behind in fulfilling orders. Packages (3) came all intact, well packed and product received in great condition. The order included:
> 5-Leaf Slipper Spring w/ Hook End for 6,000-lb Trailer Axles (2)
> U-Bolt Kit for Mounting 8,000-lb, Round Trailer Axles - 8" Long U-Bolts (2)
> Tandem-Axle Trailer Equalizer Kit for 2" Slipper Springs - 10-1/8" Long Equalizers (2)
> Dexter Nev-R-Adjust Electric Trailer Brake Kit - 12" - Left and Right Hand Assemblies - 6K (2)
> Mounting Bolts and Hardware for 12" Brake Assemblies (2)
> Bearing Buddy Bearing Protectors - Model 2441SS - Stainless Steel (Pair) (2)
> Bearing Kit, 15123/25580 Bearings, GS-2125DL Seal (4)
> Optronics LED Combination Trailer Tail Lights - Submersible - 40 Diodes - Driver and Passenger Side.
These items are being utilized in the total suspension replacement of a 10,000 gvwr tandem axle trailer. Good sized job for a DIY'er. I expect that it will give my JD 2038 tractor a smooth and safe ride as it is towed/ hauled down the highway.
Thank you.
I would/will strongly recommend to a friend/relative or associate.
( I'd take a picture of the "project", but there is a vicious rain storm occurring outside; perhaps one or two pics to follow at a later time).


Great product! The steel is of very high quality, not the cheap gold colored stuff that'll snap off as soon as you try to tighten it. The backing plates are good and thick, and after wrenching on them pretty hard with the impact and then a breaker bar, there is no deformation. I'm confident that these will stand up to whatever the road throws at them. As always, very fast shipping and great customer service! Thanks!


Great product and fantastic people!!!


Installed on 25’ gooseneck trailer. I’ve had no issues and have put thousands of miles and lots of heavy loads since.


Samatha was very helpful in helping with an alternative of leaf springs i needed. Reached out to me right away with the others i could use, and purchased. Now i can get my trailer back together.


everything was in good order


The specialist at etrailer walked me through the options and helped me select the perfect fit for my trailer. My trailer went from serious danger on the road to a 10 minute fix! Thanks for your help!


I am very happy with this product. everything fit as if the trailer was new. product is Excellent.
Thank you etrailer.


Exactly as I ordered i will be ordering more products from etrailer great service and fast shipping.


Direct replacement perfect fit.


Awesome parts, prices, and service. I highly recommend etrailer.


Good job fast and smooth l sell commercial and i need service


Heavy duty product. Love it!!


Very fast shipping! even quicker than expected. Heavy duty product. Great communication. Thank you!


They worked and fit great

Nathan P.


Still doing great

by: 07/21/2021


Worked well .


Fit as they should, quality parts at and affordable price.


It was exactly what I was looking for at a good price thank you


Fit and work great


Worked well


Thanks they worked great


Fast shipping, good product, excellent customer service

Show More Reviews

See what our Experts say about this Redline Trailer Suspension Parts

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    Sorry for any confusion that may have arose, but what you want is the U-Bolt Kit for Mounting 8,000-lb, Round Trailer Axles # APUBR-35. These are designed for 3 inch diameter, 8,000 lb axles and are compatible with the Roadmaster Comfort Ride Leaf Spring Suspension Kit w/ Shocks - Tandem 8K, 3" Trailer Axles # RM-2460-2580.
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  • 12 Inch Long Equalizer For 2 Inch Slipper Springs & 8,000 lb U-Bolts For Tandem Axle Trailer
    There isn't a complete kit, but I can go ahead and list out everything you need for a 12 inch long equalizer for 2 inch slipper springs, along with the mounting hardware and U-bolts for your 8,000 lb axles. Here is what you need for your tandem axle trailer: - 2 of the Equalizer for 2" Wide Slipper Springs # TREQ4541 - 8 of the Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long # 166079 - 2 of the Equalizer Bolt with Cotter Pin and Castle Nut - 7/8" Diameter # 166078 - 2...
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  • Torque for U-Bolt Kit for Mounting 8,000-lb, Round Trailer Axles
    The U-bolts on the U-Bolt Kit for Mounting 8,000 lb Round Trailer Axles # APUBR-35 are 9/16". The torque specs for 9/16" bolts on trailer suspension 65 ft/lbs - 95 ft/lbs. Torque specs depend on bolt size: 1/2" bolts: 45 ft/lbs - 70 ft/lbs 9/16" bolts: 65 ft/lbs - 95 ft/lbs 5/8" bolts: 100 ft/lbs - 120 ft/lbs 3/4" bolts: 140 ft/lbs - 160 ft/lbs
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Info for this part was:

Employee Jameson C
Expert Research:
Jameson C
Employee Cole B
Installed by:
Cole B
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Updated by:
Alexander C

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