if you have a spool you'd know it as soon as you moved the car no matter how loud. You can feel it.

cmanf IMO i think you're more likely to shred tyres than break axles.

either way they are not a good idea for street use. I have one in my GT and have driven it on the street occaisionally. its a pig. They are not good for spirited road driving through corners or opentrack racingas they promote understeer. Unfortunately i have to live with mine for a while.

that said they are a cheap way for making sure both rear wheels are putting power out there on a drag strip and if thats what you are using it for, they will last a lot longer than a clutch type LSD.

 

Be aware the clutches may be toast thus allowing both wheels to turn on jack stands but under the full load, only one will turn. I just toasted a set a couple weeks ago. 11 dollars in parts and about 4 hours work.