+1
Little known fact on those springs:
They aren't a solid ring.
If you are having a sealing issue at a particular seal, let's say "It's like my third time replacing that effing seal and it is still effing leaking! I'm sure that im putting it in correctly too!"
Well, when you go buy your next replacement, pop that little spring out and look at it really close. In one spot you'll find a joint. This is where the spring is joined end to end to form the ring. The two ends twist together, and therefore can be untwisted. Once you've figured this out, and you are now holding a spring in your hands that is no longer a ring shape, look closely at it again. One end of the spring will be a smaller diameter than the other, which allows it to twist inside the other end to connect it into the ring shape.
So back to the constant leak. If you take the end of the spring that isn't reduced diameter, and cut about 1/4" off, and then twist it back together, you "ring spring" is a little smaller now. Pop it back into the seal, and it squeezes the seal tighter, and can compensate for an axle (or a crank, or a output shaft, or an input shaft, or a cam shaft, or a... you get the point) that has a seal groove worn into it. This shouldn't be done to seals 'just because', because the extra tension will accelerate seal wear. But like any seal, you should be putting some grease on the seal lip to give it some lubrication, to help extend the seal life.
Now that I've said ring and spring and seal a thousand times each...