Replacement 4" U Bolt And Wing Nut Parts For Older Sears And Thule Cargo Box

Updated 09/28/2026 | Published 09/27/2026

Products Featured in This Question

Replacement Hardware Kit for Searsbox Cargo Box

(234)

$83.25

Replacement U-Bolt for SportRack Roof Basket

(26)

$15.56

Replacement Wingnut for Thule Cargo Boxes

(222)

$11.51

Question:

Question in regard to Part Number: TH05603. I honestly only need the U-bolts and two knobs, though I would be willing to buy the lot if that’s how it’s packaged. But my mounting plates are fine. P.S I hope you’re having a good day.

asked by: Drew T

Expert Reply:

Hey Drew!

Instead of buying the whole Replacement Hardware Kit for Searsbox Cargo Box # TH05603, you may be able to use U-Bolt # SR050059 with Wingnut # TH04877 and just order however many you need.

The one thing to keep in mind is that the original U-bolts are about 4-3/16" apart center-to-center, while # SR050059 is right around 4". That’s close enough that it may slide into the existing mounting holes as-is, but you could potentially need to spread the U-bolt slightly or enlarge the mounting holes in the box just a tad. I personally would give it a try as I'm DIY and don't mind little things like that to save money, but that is your call of course!

It would be a much cheaper option than replacing the entire mounting kit. What do you normally store in the box on your trips? I've seen people cram skis in some of the larger ones.

P.S. I am having a great Monday, I hope you are too!