Trailer Hub Dust Cap with a 2.125" Outside Diameter

Updated 09/29/2026 | 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

(668)

$11.59

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

(107)

$6.03

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?

Christopher H.

4/11/2026

I am having the same issue. my cap is 2.125" or so. I don't know the original manufacture of the trailer. @JesseM

Jesse M.

4/13/2026

@ChristopherH Yea that is definitely an uncommon size. I'm sorry to say we just don't have anything in that size.

John H.

9/28/2026

How come nobody can find this 2.125 or 2 1/8 bearing cap. I guess I’m not the only one looking for them who the heck made them.

Lazer S.

9/28/2026

@JohnH That's a very good question. From what I could find (which I will admit was basically nothing), this was a pretty uncommon size and there are currently no manufacturers making an option for it. At least not that we carry or that I could find online. What kind of trailer is this on? And do you know when it was manufactured? That may help me find something more definitive.