4L85E Planetary 1999, used and ready to install. Fits the 4L85E. Ships fast from the USA.
If your GM heavy-duty four-speed lost drive in the lower gears after a winter of plowing, or the teardown found the overdrive roller clutch in pieces and the carrier around it scored, the overdrive planetary is the part you are shopping for. This used planetary is listed for 1999, and the photo shows an overdrive carrier with its roller clutch set beside it. It suits the 4L80E and 4L85E family used in Chevrolet and GMC 2500 and 3500 pickups, Suburban and Yukon XL 2500s, and Express and Savana vans.
The overdrive section sits ahead of the Turbo 400 style geartrain. In first through third gear in the OD range, the overdrive roller clutch locks the overdrive planetary so torque passes straight through at 1:1 to the ring gear on the forward drum. For fourth gear the overdrive clutch holds the sun gear and the set overdrives at 0.75. Sonnax notes that the outer race of that roller clutch is machined into the inside diameter of this planetary, so when the rollers break up, the planetary usually goes with them. Pieces of roller can also chip the pinions and the forward drum ring gear.
Try it in manual 3 and 2. If the truck drives normally there but slips or will not move in the OD range, the overdrive roller clutch is the prime suspect, and the planetary that holds its outer race needs inspection. Once it is apart, check the race surface for pitting or brinelling, then check each pinion for rock, chipped teeth and blued washers. Rule out the hydraulic side too; the 4L85E valve body testing guide and the 4L85E pump failure guide cover pressure faults that can feel like a slip.
The 4L85E name dates from 2002, so a part tagged 1999 came out of the 4L80E side of the family, and that year matters. ATSG documented in Transmission Digest that GM widened the pinions in the front and rear carriers in 1999, from about 0.710 inch to 0.785 inch, then shimmed the sun gear 0.041 inch and changed the sun gear shaft to suit. The 4L85E's own upgrade was five-pinion reaction and output carriers. Neither change is the overdrive carrier, but it shows how easy it is to mix generations in these units. Before installing, set this carrier beside your original and compare the pinion count, roller clutch race diameter and splines. If anything differs, stop and send us your year, vehicle and VIN. Everything else for this unit is on our 4L85E parts page.
| Fits | 4L85E 1999 |
| Part type | Planetary |
| Condition | Used |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The 4L85E arrived in 2002 and shares its overdrive section design with the 4L80E. The 4L85E changes were to the reaction and output carriers. Compare this carrier side by side with yours, and send us your VIN if anything looks different.
The photo shows the carrier with a roller clutch beside it. We recommend installing a new roller clutch either way, since a failed one is usually what destroyed the old carrier.
Most often the overdrive roller clutch broke up. Its outer race is on the inside of this planetary, so roller damage scores the race and can chip the pinions. Plowing and heavy towing in the OD range load the roller clutch alone.
The overrun clutch drum hub, the forward drum ring gear, the sun gear and all thrust washers and bearings in the overdrive section. Clean the cooler so debris does not come back.
GM's current specification for the 4L80E and 4L85E is Dexron VI ATF.
