Trailer Hub Dust Cap with a 2.125" Outside Diameter

Updated 04/13/2026 | Published 06/08/2020

Products Featured in This Question

2" Lubed Dust Cap & Rubber Plug - 1.99" x 1.40" x 1.18" - Qty 1

(639)

$8.55

Zinc Plated Grease Cap - 2.333" Outer Diameter - 1.00" Tall - Drive In

(95)

$4.60

Question:

I have a hub that needs a dust cap. I measured with a ruler and the best I can tell the measurement from inside the hub is 2-1/8 inches. Could you tell me which size I need to order. The other hub is a smaller size. Weird.

asked by: Chris S

Helpful Expert Reply:

I have a couple close but not perfect to your measurements. The 2" Lubed Dust Cap & Rubber Plug - 1.99" part # DC200L-DCRP is an extremely common cap size found on a lot of trailers. Sometimes the hub will have a small bevel on them that could easily be 1/16" on each side getting us to the 2 1/8" or I have the larger Zinc Plated Grease Cap - 2.333" Outer Diameter part # TRDC-233 but with this one we are looking at it being almost 1/4" too big. I think that will cause issues with installation. When we get these measurements we use a set of dial calipers and measure inside of the bore about an inch. I really think that the first option is what you're after just take another quick look at it and see if it might be the bevel causing the measurement to be a little big.

expert reply by: Randy B

Jeff

10/4/2025

I have measured my axle hub and a dust cap from the other side and both measure 2.12 inches or 2 1/8 inch’s so where do I get dust caps that size

Jesse M.

10/6/2025

@Jeff Sorry but I am not seeing we have a dust cap in that size. What we have is 1.99" and the next closest would be 2.33". 2.12" is not a common size. What kind of trailer is this on?