Steel mini spool that locks both 28-spline axles together inside an open GM 8.2 inch 10-bolt carrier, part MS10C-28, for 1964-1972 GM cars.
If your 1964-1972 Chevelle, Nova, Impala, El Camino or first-generation Camaro leaves one black stripe at the drag strip, the open differential is sending the power to the tire with the least grip. The MS10C-28 mini spool is the cheapest way to make that 8.2 inch 10-bolt put power to both rear tires: it replaces the spider gears inside your existing open carrier and locks the two 28-spline axles together.
In a stock open 8.2, the carrier holds a cross shaft, two small pinion (spider) gears and two side gears splined to the axles. That gear set lets the outside wheel turn faster in a corner, but it also lets one wheel spin freely while the other does nothing. The mini spool is a pair of steel blocks that take the place of the side gears and spider gears. The axles slide into the splined bores, the factory cross shaft passes through the middle, and from then on the carrier, both axles and both tires turn as one unit. Nothing in it slips, wears like a clutch pack or needs friction modifier.
Because the carrier stays, you keep your existing ring and pinion, carrier bearings and backlash setup. That is the big advantage over a full spool, which replaces the carrier and means a full gear setup.
Whine on decel or a howl that changes with load is a different problem (ring and pinion wear or pinion bearings) and a spool will not fix it.
GM built more than one 10-bolt in this era, and the 28-spline count is shared with other axles, so check before you order. Count the cover bolts (10), then confirm it is the Chevrolet 8.2 and not the later 8.5. The Chevy 8.2 uses a 25-spline pinion, while the 8.5 uses a 30-spline pinion, so the pinion yoke tells you a lot. Pontiac, Buick and Oldsmobile cars of the same years often ran the BOP 8.2, a different 10-bolt with its own internal parts; confirm your axle code or housing before assuming a GTO or Tempest uses the Chevy unit. Finally, pull an axle and count the splines: this part is for 28-spline shafts only.
If you find you actually have an 8.5 10-bolt, this spool will not fit. A street-friendly option for that axle is the Eaton Truetrac for the 8.5 inch with 28-spline axles, and the Yukon 8.5/8.6 pinion yoke is the matching yoke if yours is worn. Running a 12-bolt instead? Look at the Dura Grip positraction for the GM 12-bolt car.
The listed applications are 1964-1972 GM cars with the 8.2 inch 10-bolt and 28-spline axles, including the Chevrolet Camaro, Chevelle, Impala and Nova; the listing also names the Pontiac Firebird, GTO and Tempest. Use it only in an open carrier. It does not go into a factory positraction carrier, since that unit has clutch packs where the spool blocks need to sit. If anything about your housing is unclear, send us the year, model and axle code (or VIN) before ordering.
Be honest about how the car is driven. With both tires locked, the inside tire has to scrub through every turn. Expect chirping in parking lots, a push in tight corners, heavier steering and faster tire and axle wear. For a race car, a bracket car or a trail rig that is a fair trade. For a daily driver, a limited slip such as a Truetrac or positraction is the better choice.
With the driveshaft out, it is a good time to look at the U-joints. A ball joint press and U-joint removal kit makes pressing them out a clean job.
| Part number | MS10C-28 |
| Axle | GM 8.2 in 10-bolt, open carrier |
| Axle spline | 28 spline |
| Material | Steel |
| Package weight | 5 lb |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It is built for the GM 8.2 inch 10-bolt with 28-spline axles. The 8.5 uses a different carrier and needs its own spool or locker. Check the pinion splines (25 on the Chevy 8.2, 30 on the 8.5) and count your axle splines before ordering.
No. A mini spool goes inside your existing open carrier, so the ring gear, pinion, carrier bearings and backlash stay as they are. You reuse the factory cross shaft and C-clips.
You can, but it is not pleasant. Both rear tires turn at the same speed, so they scrub and chirp in turns, steering gets heavier and tires and axles wear faster. It is meant for drag, track or off-road use.
Plain 75W-90 gear oil. There are no clutches in a spool, so you do not need a limited-slip friction modifier.
No. It only fits an open carrier, because it takes the place of the open spider gears and side gears. A posi carrier has clutch packs in that space.
