spool vs mini spool
A spool is a solid carrier for the ring gear. It does not have any mechanical pieces internally. The axle shafts slide into each side of the spool and the ring gear bolts directly to it. Both axles will spin the same speed all the time. They will never spin independently from one another. End result is a strong 1 piece permanently locked rear end.
Refer to link for an illustration of a spool.
http://www.jegs.com/i/Moser/718/5S9F31/10002/-1
A mini spool is a piece that simply replaces your existing carriers spider gears. It goes inside of your carrier and each axle sides into it. A hardened pin slides through the mini spool (perpendicular to the axles) and into the carrier linking them all together as a locked unit. This setup relies heavily on the hardened pin and is known to commonly break. This setup is not nearly as strong as the spool setup but the end result is the same. Refer to the link for an illustration of a mini spool.
http://www.jegs.com/i/Richmond+Gear/...931-1/10002/-1
A permanently locked rear end will cause a street driven car to track while turning. The outside tire will try to turn at a faster rate of speed resulting in the inside tire chirping (spinning) around the corner. This can cause drive shaft u joint failure or axle shaft failure in heavy, high horsepower, or daily driven applications.
A better solution for a street driven vehicle is a Locker or a limited slip unit. These 2 components will lock the differential, making it a 2 axle drive differential, when a predetermined amount of load is applied. During normal operations, the differential will be open (single axle driven) and have a greater street manners.
Refer to link for an illustration of a spool.
http://www.jegs.com/i/Moser/718/5S9F31/10002/-1
A mini spool is a piece that simply replaces your existing carriers spider gears. It goes inside of your carrier and each axle sides into it. A hardened pin slides through the mini spool (perpendicular to the axles) and into the carrier linking them all together as a locked unit. This setup relies heavily on the hardened pin and is known to commonly break. This setup is not nearly as strong as the spool setup but the end result is the same. Refer to the link for an illustration of a mini spool.
http://www.jegs.com/i/Richmond+Gear/...931-1/10002/-1
A permanently locked rear end will cause a street driven car to track while turning. The outside tire will try to turn at a faster rate of speed resulting in the inside tire chirping (spinning) around the corner. This can cause drive shaft u joint failure or axle shaft failure in heavy, high horsepower, or daily driven applications.
A better solution for a street driven vehicle is a Locker or a limited slip unit. These 2 components will lock the differential, making it a 2 axle drive differential, when a predetermined amount of load is applied. During normal operations, the differential will be open (single axle driven) and have a greater street manners.
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A mini spool is cheaper, but weaker and heavier. With a mini spool, it will still only be as strong as the differential housing it is in. Plus, you are just adding weight to the differential that is all ready in there. In my opinion, it's best just to spend the money and get a full spool if you do decide to go that route.
thanks for the explaination. i was looking to pick up a used 9 inch the the owner said had a mini spool in it . I had asked him the difference and he stated that there was no difference, both do the same thing just one goes inside of the housing where the spider gears go. I didnt quite follow, but thanks to your explanation its much more clear.
