6L90 Sprag Clutch 2006, used and ready to install. Fits the 6L90. Ships fast from the USA.
This is a used original-equipment low sprag clutch pulled from an early GM 6L90, listed for the 2006-and-up build that the six-speed family launched with. It is the budget route for a rebuilder who needs the factory part for an early unit, a 2007 or 2008 Silverado 2500HD or Sierra 2500HD with the 6.0L, an Express or Savana van, rather than paying for a new GM kit. If your truck slips or acts like it is in neutral when pulling away in Drive, or you have a teardown on the bench with a scored sprag, this page explains what to check before you order.
Inside the 6L90 the low sprag is the one-way clutch that holds the output carrier stationary in first gear. On launch the low/reverse clutch is applied alongside it to take the initial hit; at roughly 2 mph that clutch drops out and the sprag holds first gear by itself. When the transmission upshifts to second the sprag simply overruns, so the 1-2 shift is smooth without a timed clutch exchange. Because it is purely mechanical there is no solenoid or sensor to fault, and the only thing that wears is the sprag elements and the hardened races they ride on.
A neutral feel on launch is also what a burned 1-2-3-4 clutch or a leaking feed circuit produces, and GEARS magazine notes the two are often confused. Drive the truck in manual low: the low/reverse clutch holds first there, so if manual low is solid and Drive slips, the sprag is the likely fault. Slip in second through fourth as well means the 1-2-3-4 clutch or its feed, including the worn checkball #1 condition covered in our 6L90 common problems guide. Early units also had a known pump cover and line pressure issue; if pressure is low, start with our 6L90 pump failure symptoms article.
The listing is marked 2006 for the 6L90. Light-duty 6L80 units appeared for the 2006 model year, while 6L90 trucks and vans start with the 2007 model year, so in practice this sprag is for early 6L90 builds. GM revised parts during the run and a later new sprag kit, 24248958, carries the 2007-2023 applications; Sonnax also makes different sprag rebuild kits for the 6L80 and 6L90, so a 6L80 sprag should not be assumed to fit. Lay your old sprag next to the photo and compare the outer spline count, the element row and the race diameter, or send us your year and VIN and we will confirm. If you would rather have a new unit, see the new 6L90 sprag clutch, and browse the full range on the 6L90 parts page.
| Fits | 6L90 2006 |
| Part type | Sprag Clutch |
| 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 listing is marked 2006, the first year of the 6L family. The 6L90 itself went into trucks and vans for the 2007 model year, so treat this as a sprag for early 6L90 units and match it to your old part.
A sprag that locks firmly in one direction, freewheels smoothly in the other and rides on an unpitted race is serviceable. Inspect it before installing and replace the race if it shows wear. It carries our 1-year warranty.
Compare first gear in Drive against manual low. Manual low uses the low/reverse clutch to hold, so if manual low pulls and Drive slips on launch, the sprag is the likely cause.
The low/reverse frictions and steels, all seals and gaskets from an overhaul kit, and any race that is pitted or polished.
Dexron VI ATF. Reset transmission adapts and run a Service Fast Learn after the rebuild.
