4L80E Planetary 1999, used and ready to install. Fits the 4L80E. Ships fast from the USA.
A whine that rises and falls with road speed, a pan full of glitter, or gear ratio codes that keep coming back after the shift solenoids were replaced can all lead to the planetary gears at the back of a 4L80E. This listing is a used late-design 4L80E rear planetary for 1999 and later units: a four-pinion carrier with angled (helical) gears, the wider late pinions measured at .795 inch, and the reluctor ring still on the carrier. It was checked and is in very good used condition. It suits the late 4L80E in Chevrolet and GMC 2500 and 3500 pickups, Suburban 2500 and the Express and Savana vans.
Behind the overdrive section, the 4L80E uses the same compound geartrain idea as the Turbo 400: two planetary sets sharing one sun gear. Depending on which clutches and one-way devices are holding, those sets produce first, second, third and Reverse, and the carrier tied to the output delivers that torque to the driveshaft. Every pinion runs on needle rollers around a hardened pin, with thrust washers on each side. When those rollers and washers wear, the pinions tip, the gear mesh goes noisy, and debris starts circulating through the valve body and the converter.
Sonnax points out in its planet service article that this basic gear system is rated at 885 lb-ft in the 4L80-E, and that worn pins and needles often feel smooth by hand even when they are badly worn. That is why a used carrier like this one is worth installing when yours shows play, pitting or heat discoloration.
Separate noise from electrical faults first. Ratio codes are not always gears: Transmission Digest's March 2001 bulletin describes 4L80-E trucks that logged undefined gear ratio errors because an output carrier without a speed sensor exciter ring had been installed, so the sensor read the park lugs instead. Our 4L80E input and output speed sensor guide covers testing the sensors. If the codes check out and the noise tracks road speed, drop the pan and look at the magnet. Once apart, rock each pinion, check end play and look for blued pins. More failure patterns are in the 4L80E common problems guide.
This is the late carrier for 1999-and-later 4L80E transmissions. Sonnax lists different pinion rollers and washers for the output and reaction planetaries from 1999 on, while 1998-and-earlier units used .750 inch wide pinion gears, so match the generation and pinion width of the carrier you remove. Keep the reluctor in mind too. The same TD bulletin notes GM dropped the output speed sensor and its exciter ring on K (4x4) trucks starting in 1994, while 2WD applications require a working sensor and a ringed carrier. Put this ringed carrier in any truck that reads output speed from it. Send us your year and VIN if in doubt. Other hard parts are on the 4L80E collection page.
| Fits | 4L80E 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.
It is a late 1999-and-up carrier with wider pinions. Earlier units used .750 inch pinions and different pinion hardware, so match it against the carrier you remove or send us your year and VIN before ordering.
Trucks that read output speed off the carrier need the exciter ring. Without it the sensor can pick up the park lugs and set gear ratio errors. This carrier has the ring.
Replace the thrust bearings and washers around it, install fresh seals and clutches from an overhaul kit, and flush the cooler and lines so debris from the old gears does not return.
Yes. The rear gearsets carry load in first, second, third and Reverse, so a worn set often whines in those gears and quiets down in fourth, where the overdrive section changes the power flow.
Dexron VI ATF. Check the level hot after the test drive.
