How to Measure a Trailer Wheel to Fit a Baby Moon Center Cap

Question:

Could you please tell us how to measure right for the baby moons for my vintage trailer ? They have small cap in the middle that covers the please where they check the grease. now smart on this Then there are the 5 lug nuts and then 3 of the outside knot things. I have ordered 2 different ones from yall and neither worked. I was told at a trailer place here I need a 14 inch set. I am confused and I probably have you confused by now. Sorry. Any help you can give me will be great. Thank you

asked by: Kathy

Expert Reply:

The measurement that you will want to take is the outer diameter of the inner ring and the outer diameter of the inner ring with one of the tabs (see photo). You will also want to count the bolt holes on the wheel and know the wheel diameter.

The Baby Moon Center Cap, # AM90086, will fit 13 inch, 14 inch, or 15 inch 5-lug conventional steel wheels. The outer diameter of the inner ring should be 9 inches and the outer diameter of the inner ring with one of the tabs should be 9-1/4 inches.

We also carry the Baby Moon Center Cap, # AM981306, for 15 inch 6-lug conventional steel wheels. The outer diameter of the inner ring of the wheel should be 10-1/8 inches and the outer diameter of the inner ring with one of the tabs should be 10-1/4 inches.

expert reply by: John H