700R4 Sun Shell 1982, new and ready to install. Fits the 700R4. Ships fast from the USA.
Lost 2nd and 4th, or Reverse, in a 700R4 out of a Chevy C/K pickup, Blazer, Suburban, Camaro or Corvette, and found the sun shell splines stripped or the shell cracked? This is the Sonnax SmartShell heavy-duty reaction shell kit, part number 77749-02K, new and made in the USA. It replaces the factory sun shell in the 700R4 and its successors, the 4L60, 4L60E, 4L65E and 4L70E, and fixes the weak points that make the original shell one of this transmission's best-known failures.
The sun shell, which Sonnax calls the reaction shell, is the thin steel drum that wraps around the planetary gearsets and connects the reverse input drum and the 2-4 band to the sun gear. When the 2-4 band clamps the reverse input drum in 2nd and 4th, the shell holds the sun gear still. In Reverse it drives the sun gear. All of that torque passes through the splines in the shell hub, and on the factory part those splines strip or the hub breaks away from the shell, especially behind a modified engine or a heavy truck. A second weak spot is the small bearing captured in the rear planet, which can fail from thrust loads on both OE and thicker aftermarket shells.
The kit includes:
The larger bearing and custom race route thrust loads through the carrier and bypass the captured planetary bearing, so this kit addresses spline stripping, hub breakage and rear planetary bearing failure together, while staying only slightly heavier than the OE shell.
The 700R4 has no trouble codes, so these symptoms are confirmed by teardown, not a scan tool.
No 2nd and no 4th together can also come from a burnt 2-4 band or a worn servo pin bore, and no Reverse can be a reverse input clutch problem. Check line pressure and the TV cable first; our 700R4 common problems and fixes guide walks through those causes. With the pan off, look for steel splines and chunks in the filter. With the unit apart, the stripped shell is obvious: the hub turns freely inside the shell or the teeth are gone. If your 700R4 also has a delayed engagement, read 700R4 delayed engagement causes as well.
Our listing title says 1982 because that is when the 700R4 started; the SmartShell fits all 1982-on 700R4 units and the 4L60, 4L60E, 4L65E and 4L70E. It works with your original rear sun gear. It replaces your low/reverse roller clutch race, so the race in the kit must be used, and its inner lugs lock into the rear planet. If you have a custom or race build with a non-stock rear carrier, check fit before assembly, or send us your year and VIN. Browse all 700R4 parts for the rest of the job.
| Fits | 700R4 1982 |
| Part type | Sun Shell |
| Condition | New |
| Brand | Sonnax |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. Despite 1982 in our title, the SmartShell fits all 1982-on 700R4 units and the 4L60, 4L60E, 4L65E and 4L70E.
The heavy-duty reaction (sun) shell, an enclosed thrust bearing and a custom low/reverse roller clutch race. You reuse your original rear sun gear.
Yes. The original race and the black plastic thrust washer are discarded; the kit's race and bearing are what carry the thrust load.
Typically no 2nd and no 4th, or no Reverse, with metal in the pan. The hub splines strip and the shell no longer holds or drives the sun gear.
Input end play of .005-.035 in., adjusted with the selective washer at the input housing thrust bearing.
Dexron-VI, which meets the older Dexron specs the 700R4 was originally filled with.
