4L80E Planetary 1991-2000, used and ready to install. Fits the 4L80E. Ships fast from the USA.
If your 1991-2000 Chevrolet or GMC 2500 or 3500 pickup, Suburban 2500, full-size GM van or Hummer H1 lost Drive after a hard pull or an overheat, but still moves when you pull the lever into manual 2 or 1, the front overdrive section of the 4L80E is the first place to look. This listing is a used overdrive planet kit for the early-design 4L80E: the overdrive planet, the drum that goes with it, and the input shaft, built around the black sprag type one-way clutch used in these years. The planet teeth were inspected for chips, the input shaft was checked for straightness on a roller, and the splines were checked before it was listed.
The 4L80E is a three-speed geartrain with a small planetary gearset bolted on ahead of it to make fourth gear. The input shaft carries engine torque from the converter into that front planet. In first, second and third, a one-way roller clutch housed in the overrun drum locks the overdrive planet so it spins as a solid unit and sends power straight back to the main geartrain. When the computer commands fourth, the fourth clutch holds the overdrive sun gear, the roller clutch freewheels, and the planet steps the output speed up.
The catch is that in the D range the roller clutch holds the load alone. The overrun clutch only applies in manual 2 and 1, which is why a truck with a failed roller clutch often still crawls in the manual ranges. Transmission Digest's Sonnax TASC Force write-up on 4L80-E overdrive clutch failure ties the failure to plow and heavy-towing trucks, where heat melts the plastic cage of the roller clutch and it fails fast.
Do a range check first: drive in D, then in manual 2 and manual 1. Losing only the D range points at the overdrive roller clutch. Pull the pan and look at the debris; burnt fluid and plastic chunks back up the diagnosis. Speed sensor faults can also set ratio codes that look like a slip, so test the input and output signals using our 4L80E speed sensor symptoms guide. The 4L80E common problems and fixes guide walks through the overdrive roller clutch failure in more detail.
This kit is for 4L80E transmissions built 1991 through 2000 that use the early black sprag type overdrive assembly. GM changed the overdrive parts for 2001 and later units, so if your transmission was built in 2001 or later, use the 2001-and-up overdrive planet kit instead. If you want to convert an early unit to the later design with all-new small parts, the overdrive planet and drum update kit is the option. Units can be swapped between trucks over the years, so confirm what is in your case by the transmission ID tag, or send us your year and VIN and we will check it. Browse the 4L80E parts collection for the rest of the hard parts.
| Fits | 4L80E 1991-2000 |
| 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 overdrive planet, the matching drum and the input shaft, built with the early black sprag type one-way clutch. It is a used assembly that was inspected for chipped teeth, a bent shaft and worn splines.
No. This kit is the 1991-2000 black sprag design. 2001 and later 4L80E units use the later overdrive parts, so order the 2001-and-up kit or send us your VIN to confirm.
In manual 2 and 1 the overrun clutch holds the overdrive planet along with the roller clutch. In D the roller clutch holds alone, so when it fails you lose drive only in that range.
Overrun and fourth clutch seals and frictions, worn thrust washers and bushings, the filter and all the fluid. Flush the cooler so old debris does not reach the new parts.
Dexron VI. It replaces the older Dexron III in these transmissions, and the level should be checked with the fluid at normal operating temperature.
Watch the transmission temperature gauge, keep the cooler clean, and use the manual ranges when plowing or towing slowly so the overrun clutch shares the load.
