I've seen third member assemblies that advertise they have a "spool" carrier, which from what I understand is like a full time locker. Could someone explain to me:

1) Is that what a spool is ^ (i.e. are spools just full time lockers)

and

2) What is the difference between a spool carrier and a "mini"-spool carrier?


Thanks for the help guys...

 

A mini spool fits inside the differential, replacing the spider gears locking the rear axles together solid with a chunk of metal. The only thing to transfer torque to it is the cross pin and it has a bit of room between the carrier and the mini spool.

A full spool replaces the entire differential, is one piece, and has splines in it to lock the axles together. it is both stronger and lighter than a differential, and has no provision for turning corners whatsoever.

 

Right, so people with the Full Spools experience "ratcheting" around corners right?

Now, with a mini-spool does it provide turning capabilities or no?

Thanks for the response

 

Full spool has no ratchet. When you turn one tire must slip or you dont turn. You can also break axles by turning with a full spool or mini spool, that is why NHRA and IHRA both require aftermarket axles with no C-clips when running a spool. both tires turn the same rpm all the time with a spool of any type.

Also due to the lack of torque absorbing capacity of the minispool, they are not recomended for drag racing and street driving. A hard launch with sticky tires will break a minispool pretty quick if not instantly.

A detroit locker is not a spool. it is a differential that has a high torque capacity. its lugs popping in and out while turning are what create the clicking noise.

Spools are race only items. yes people have run them on the street, but if its a daily driver, they are either pushing thier luck or pushing the car often because something in the rear end broke. You could get away with it if you have a low powered vehicle and skinny non sticky tires that slip when turning, and a beefy rear end with large axles, but something like an 8" with a full spool will be breaking stuff with any sort of sticky tire.

 

What is the advantage of having a mini spool if it breaks under any sort of high torque applications?


(BTW thanks Thumpin for your responses! )

 

Its a cheap way for circle track guys to get both wheels to turn at the same speed. its most prevalent on dirt tracks where there isnt much traction, you can go around the track like a sprint car, sidewayz.. lol.. and not break anything. The circle track cars are alreay moving so there is no initial shock like in a drag race.

The launch is probably the toughest on parts in a drag car, getting the mass moving in a short time requires a massive amount of torque applied to the rear wheels, especially to get lower than a 1.5 second 60 ft. Circle track doesnt have that, neither do landspeed racers. They have a rolling start and that is a huge difference.

1.5 and lower you can actually injure yourself on the launch if you arent sitting correctly in the seat. Around 1.2 and under it feels like you were sitting still at a red light and a fully loaded semi just rear ended you and propelled you to 60mph in less than 2 seconds. that is alot of torque going to the differential, axles, and tires. One little 1/2" thick cross pin isnt going to hold that much torque, it will shear off and destroy a bunch of stuff inside.

 

and you're welcome..

 

And neither a spool or a mini spool should be anywhere near a street car.

 

Never said it was, just wanted to know the differences, thx.

 

After going over the dialog between 65 mojoe and Thumpin 455.I have some questions.
1. How does one go about converting an open 9 inch rear to a limited slip one? I have mustangs with both. What is the proceedure for changing the center section? Thank you.