New 5-pinion front planet carrier (Remco 77747B) for GM 4L60E, 4L65E and 4L70E units, 1982-2016, to replace a worn or broken 4-pinion carrier.
A 4L60E that whines in one gear, leaves bright metal in the pan, or suddenly loses drive in some ranges after towing or a power upgrade has often broken its front planetary carrier. This is a new front planet carrier sold under Remco part number 77747B. It uses five pinion gears instead of the four most 4L60E units left the factory with, the same layout GM used in the stronger 4L65E and 4L70E, and it is listed to fit 700R4, 4L60E, 4L65E and 4L70E transmissions from 1982 through 2016.
The 4L60E builds its four forward gears and reverse from two simple planetary gearsets, a front (input) set and a rear (reaction) set, tied together by the sun shell and the output shaft. The carrier is the cage that holds the pinion gears on their pins, meshed between a sun gear in the middle and an internal ring gear on the outside. Depending on which clutch or band is applied, the carrier is either driven, held or turning with the output, and every bit of torque passing through that gearset is shared among its pinions. With four pinions, each gear tooth and each pinion pin carries a quarter of the load; with five, the same torque is split five ways. Sonnax makes the point that moving from four to five pinions spreads the load more evenly on the sun gear and reduces ring gear flex, which is why a 5-pinion carrier is the standard upgrade in a rebuild behind a modified engine or a truck that tows.
A carrier failure rarely happens alone. The 4L60E's well known sun shell spline failure also produces a no-drive or no third and fourth complaint, and a carrier that came apart usually marks up the sun gear, ring gear and thrust bearings around it.
A gear whine that changes with road speed but not engine speed points into the geartrain rather than the pump or converter. Drop the pan: clutch-colored paste is normal, but bright steel chunks mean a gear or bearing has failed. With the unit torn down, rock each pinion on its pin, check end play and inspect the teeth. Our 4L60E common problems guide covers how to tell a geartrain failure from a sun shell or clutch failure.
The listing covers the GM 700R4, 4L60E, 4L65E and 4L70E from 1982 to 2016, which spans Silverado, Sierra, Tahoe, Suburban, Yukon, S10, Blazer, Camaro, Corvette and many other GM applications. Within that long run GM changed output shafts, sun gears and thrust parts, so lay the old carrier beside the new one and compare the spline counts and thrust surfaces before you build. Send us your year and VIN if you want a second check, or see our full 4L60E parts collection.
The carrier ships with its pinions installed. It does not include the ring gear, sun gear, thrust washers, bearings or bushings. Clean every mating part and replace any gear with pitted or chipped teeth rather than running it against the new carrier. Lube the pinions and thrust surfaces with ATF or assembly lube, install new thrust bearings and washers, and confirm overall end play before closing the case. If the old carrier broke, check the reaction sun shell closely; a GM genuine reaction sun shell or the heavy-duty Beast sun shell is cheap insurance on a high-power build. Most carrier jobs happen during a full overhaul, so pair it with a 4L60E master rebuild kit, then fill with Dexron VI and check the level hot.
| Part number | Remco 77747B |
| Transmission | GM 700R4, 4L60E, 4L65E, 4L70E, 1982-2016 (per listing) |
| Design | Front planetary carrier, 5 pinion gears |
| Condition | New |
| Shipping weight | 8 lb |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
This carrier is listed to fit 700R4, 4L60E, 4L65E and 4L70E units from 1982 to 2016 and is the common upgrade for a 4-pinion 4L60E. Compare spline counts and thrust surfaces with your old carrier before assembly, since GM changed related parts over the years.
The front planetary carrier with its pinion gears installed. The ring gear, sun gear, thrust washers, bearings and bushings are not included.
For a stock truck with a healthy original carrier, no. It is worth it when the old carrier is worn or broken, or when the transmission is behind a modified engine or tows regularly, because the load is spread across five pinions instead of four.
New thrust bearings and washers, any sun or ring gear with damaged teeth, and the reaction sun shell if it shows spline wear. Most builders install it as part of a full overhaul with a master rebuild kit.
Dexron VI ATF. Check the level hot after the first drive cycle.
