6L90 Planetary 2006, used and ready to install. Fits the 6L90. Ships fast from the USA.
Gear whine that climbs with road speed, a truck that pulls in some gears and not others, or bearing needles on the pan magnet all point toward the gear train in a 6L90. This used OEM planetary is for owners and shops rebuilding a GM heavy-duty six-speed who want a factory gearset at a used-part price. It suits the 6.0L Silverado and Sierra 2500HD/3500HD, the Suburban 2500 and the Express and Savana 2500/3500 vans, once you have matched it to your unit as described below.
The 6L90 has only two gearsets. At the front is a simple planetary whose sun gear is fixed to the stator support, so it always turns out a reduced speed. Behind it is a Ravigneaux compound set with two sun gears, long and short pinions on one carrier and a single ring gear that drives the output. Five clutches and a low sprag decide which members are driven or held, giving six forward gears and Reverse with no direct 1:1 ratio. Since every gear runs through the pinions, worn pinion bearings or a damaged carrier make noise in more than one range. GM made the 6L90 input and output gearsets stronger than the 6L80 versions and lengthened the case by 1-3/8 inch to fit them, which is why towing trucks and vans got this unit.
A 6L90 pump whine follows engine rpm and is present in Park, while planetary noise follows road speed and goes quiet when the truck stops. Rev the engine in Park and listen; if the noise is there, read our 6L90 pump failure guide before buying gear train parts. Low fluid also causes whine on these units, so check the level hot at the check plug first. If the noise only happens moving and the pan shows bearing debris, the carriers need to be pulled and checked for pinion end play, rough pinions and chipped teeth.
This planetary is listed for 2006. The 6L80 launched in 2006 and the 6L90 followed in 2007 model year trucks, so use the year as a reference only. Before you order, compare the listing photo against your part: count the pinions and splines, measure the hub and shaft, and check that it is the same gearset position, front or rear. A 6L80 gearset will not work in a 6L90 case. If you want us to check it for you, send the year and VIN. The full range of 6L90 hard parts is on the 6L90 collection page.
Heavy towing is the main reason these gear trains wear out early; our Silverado 2500 6L90 problems guide explains how load and heat play into it.
| Fits | 6L90 2006 |
| 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 2007-2014 and 2015-2019 Silverado and Sierra 2500HD/3500HD with the 6.0L, the 2008-2019 Suburban 2500, Express and Savana 2500/3500 vans from 2010, plus the Camaro ZL1 and CTS-V. Send us your VIN to confirm.
No. Pump whine follows engine speed and is there in Park. Planetary whine follows road speed and changes from gear to gear.
No. The 6L90 uses stronger input and output gearsets in a case that is 1-3/8 inch longer, so 6L80 gearsets are not a swap.
Thrust washers and bearings at every position you disturb, all clutch soft parts if there was debris, the filter and seal, and the cooler should be flushed.
Yes. Reset the transmission adapts with a scan tool after filling with DEXRON-VI, then road test so the TEHCM can learn the new parts.
