How Much Pressure is Required to Install a Trailer Grease Seal

Question:

Thanks Conner. I understand how the seals are installed. I just have a handful l've accumulated that all have the same OD, but not ID. I was just testing the seal fit on the spindle before installing in the hub. The spindle is 1.75 x 1.25. The seals that came with the hubs originally have a 22333TBN number on them. The handful of seals I have that seem to be the appropriate replacements have a 225337375TB number. Seems like that number is referencing the spindle size it fits, but hard to tell. It's mainly the various numbering schema on the seals themselves that is confusing. It's also interesting how close some of the seals are in ID but not exactly the same. I've got two different ones that I can squeeze onto the spindle but seems a little tight...probably not the right ones. Must be a lot of spindles out there that are very close in size. I'll get it figured out, but thought I'd ask.

asked by: Jim

Helpful Expert Reply:

For starters, the grease seal installs on the trailer hub, not the spindle. It should be a rather tight fit and usually requires a hammer and block of wood to install. In order to make sure you have the correct one, you will need to measure the outer diameter of the spindle and then the inner diameter of the trailer hub where the grease seal sits. These measurements will need to be taken with a digital caliper to the nearest thousand of an inch. If you can let me know what the above two measurements are I will be happy to let you know what seal is correct for your trailer.

I have attached a photo that shows where to measure.

expert reply by: Conner L

click to enlarge

Jim

9/28/2018

Conner L.

9/28/2018

Based on the spindle dimensions (1.25" outer and 1.75" inner), you have a 5,200 lb axle and the most common grease seals for a 5,200 lb axle are part # GS-2125DL which has a 2.125" inner diameter and 3.376" outer diameter or part # GS-2250DL which has a 2.250" inner diameter and 3.376" outer diameter. The 2.125" seal is usually on older trailers and the 2.250" seal is usually on newer trailers but as they are only .125" apart you will need to measure with a digital caliper.