The seal problem

I'll go into a little more detail about the front disc brake inner bearing seal problem. I have not been able to contact the kit manufacturer; I assume they are having problems from Hurricane Sandy down in NC.

First we'll take a quick measurement of the seal OD. It's 2.634 (all dims in inches). Note the engraving on the dial caliper, I'll get to that later.

Here is the rotor area where the seal goes. It measures 2.400.

 Subtraction shows the seal to be too big by a monster .234. This is almost 1/4", no way this is the correct seal. I didn't need to measure with a dial caliper to see the interference, but there's a reason I did.

Here's the inner part of the spindle where the seal goes. 1.874. Write all these numbers down for future reference. I mean I did, you don't have to there at home. 

 There's a little thumbscrew on the dial caliper that can fix the jaws. You can just see it upper right in the photo. I used it here.

I can then insert the fixed caliper into the ID of the seal. The seal is hard rubber here, so measuring it accurately is difficult. The caliper jaws are used as a go/no-go gauge to see if the ID is near correct. The caliper slides into the seal with just a little drag, so we know the seal would wipe on the spindle correctly. If it fit the rotor.

Here is a side shot of the seal. This metal outer ring must sit down flush into the machined area of the rotor. I had it jammed in behind the rotor, and it caused major mechanical binding, as you can imagine. I am not familiar with a seal that has a protuding lip like this either. I just don't get this. 

What I did get is an accurate set of numbers. Now when I get in touch with the manufacturer, I can speak about the problem in concrete terms, not just guesses or vague statements. I can tell them exactly what I have, and exactly what I need, down to the thousandth of an inch. Thinking about this, I am going to go back and measure the seal width, and the seal seat in the rotor, so I have those too.

If I have to, I can now troubleshoot this myself. I can bring my caliper to the auto parts store, and physically measure seals right there, until I find the correct one. Only need the correct ID, OD, and width. This is part of swapping non-stock parts.

 

Here is my dial caliper cleaned and resting in its case (the cigar is not part of the story. It's really not part of any story, it just "is". Try to ignore it).

I inherited the caliper from my late father, and it is one of my most prized and cherished possessions. It measures to the thousandth of an inch (finer with some interpolation). Not everything needs to be measured with this accuracy, but many times close enough is not good enough. I am reminded of my dad whenever I use it, since it has "EF" engraved on it. It is on extended loan from a once-prominent manufacturing company in East Fishkill where he used to work.

Even if you had one and didn't know how to read it right, you could write down some numbers from it and bring them to someone that could figure things out. Now digital calipers are available for as little $10 (!) from Harbor Freight Tools, and being digital, you have the number right in front of you, no adding up the different scales.

Finally, like I alluded to, having real and accurate numbers gives you authority when you visit a parts store. You tend to be taken more seriously when you declare your needs to the thousandth of an inch, and are ready to verify part measurements right at the counter.

Stay tuned for more on the seal story.