StephenB -

Here is a lot more info than you requested. The first part with the Tech Tip by Jeff Erickson answers your question. The rest of my post are fluffy details for those of us with the dreaded "picky gene".

I used this Tech Tip by Jeff Erickson to lube the speedometer in my '54. It stopped the URK, URK, URK noise coming from my speedo.
> CLICK for Jeff's Tech Tip

Pay particular attention to this part of his Tech Tip. It refers to the brass cap that you questioned. Click on the "[ pix ]" in his Tech Tip to see the brass cap etc.

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> Starting back at the base of the speedometer assembly

"If you look it over, you will notice a very small brass soft plug [ pix ] . I used a tiny screwdriver, inserted it in softly and gently turned it counter-clockwise and pulled the plug right out. Underneath it is a very small piece of felt which can be removed with tweezers or a needle. [ pix ] Apply one drop, maybe two at most, and give the speedometer a spin to make sure it's thoroughly lubricated. I cut a small piece of new felt (but the old one can be reused) [ pix ] and inserted it into the hole. Apply one more drop of oil and gently pop the brass soft plug back in place. Push gently but firmly so it's seated tight. [ pix ] Surprisingly enough, there was still wet oil inside when I pulled the plug out. Not bad after 60 years!"

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I used 3-in-One 20w machine oil in the blue and white bottle to lube the felt. My speedo still had the felt beneath the brass cap. I didn't disassemble or reface the odometer.

Be gentle when you remove the speedometer needle from the mounting shaft. The shaft is very brittle and easily broken. Mine came off OK, but I broke the shaft on a speedo that I was using for practice. I took the speedo in my '55 MG TF to a watch maker to have the hands of the clock, which is on the speedo face, removed.
> CLICK - Broken shaft

John Rooney's Tech Tip on refacing the gauges on his '53 is a good guide to refacing your speedo and other gauges.
> CLICK for John's Tech Tip

Here is the saga and the results of refacing the gauges in my '54 3104.
> CLICK for Stovebolt reface thread

If you want to complete the rehab of your '54 dash, here are my CHEVROLET letters and speaker grille stripes on my '54:
> CLICK for Stovebolt dash thread

A few more picky details:

> CLICK - Dual clip for mounting speedo cable and wiring harness onto firewall - American Classic Truck Parts part # FA-113

> CLICK - 70" metal case speedo cable - American Classic Truck Parts part #SPC-2

> CLICK - correct two-hole and three-hole grommets for firewall

- Lonnie

- Lonnie
My '54 3104
Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post.
lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt.

OLD STUFF ... houses, furniture, cars, wine ... I love it all