6L90 Sprag Clutch 2007, new and ready to install. Fits the 6L90. Ships fast from the USA.
A 2007 Silverado 2500HD or Sierra 3500HD that rolls away from a stop like it is in neutral, then grabs a second later, is one of the classic first-year 6L90 complaints, and the low sprag is a frequent cause. This is a new sprag clutch for the 2007 6L90, the launch year of GM's heavy-duty six-speed behind the 6.0L gas V8. The listing photo shows the sprag assembly with its retaining rings, so a rebuilder with the unit apart can replace the worn part instead of reusing a tired factory sprag that already has high miles of launches on it.
The 6L90 starts in first by locking the output carrier of its rear compound gearset to the case. Two things do that job together. The low sprag is a one-way clutch: its tilted elements wedge between an inner and outer race when the carrier tries to turn backward and roll free when it turns the other way. The low/reverse clutch is applied alongside it for the first moment of take-off, then releases at roughly 2 mph and leaves the sprag holding first by itself. Because the sprag simply overruns when second gear comes in, the 1-2 upshift needs no timed clutch hand-off. That design is smooth, but it also means first gear in Drive depends entirely on a part with no sensor and no trouble code of its own.
A worn sprag is easy to mistake for a failed 1-2-3-4 clutch, because both make Drive feel like neutral. Use the range selector to split them: manual low applies the low/reverse clutch to hold first, so if manual low is solid and Drive slips on take-off, the sprag is the suspect. If second, third and fourth also slip, look at the 1-2-3-4 clutch, its cracked-piston history and the worn number 1 checkball in the valve body, all covered in our 6L90 common problems guide. A gauge reading belongs in the diagnosis too; low line pressure from the pump cuts holding power everywhere, and our 6L90 pump failure symptoms article shows how to test it. For scan-tool checks on a truck that shifts badly, see the Silverado 2500 6L90 shift problems guide.
This part is listed for the 2007 6L90 (RPO MYD). In 2007 that means the new-body Silverado and Sierra 2500HD and 3500HD with the 6.0L. GM revised 6L-family hard parts during the production run, and the 6L80 and 6L90 do not share every geartrain part; Sonnax even sells separate sprag rebuild kits for each. Before ordering, check the RPO code on the glovebox or door label, lay your old sprag beside the photo and compare outside diameter, element count and how it locks in the race, or send us your year and VIN and we will confirm. Other years are on the 2006-listed 6L90 sprag and 6L90 sprag clutch pages, and everything for this unit is on the 6L90 parts page.
| Fits | 6L90 2007 |
| Part type | Sprag Clutch |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Yes. GM introduced the 6L90 for the 2007 model year in the new Silverado and Sierra 2500HD and 3500HD. Light-duty 6L80 trucks came first, which is why some catalogs list 6L-family parts as 2006-up.
Drive the truck in manual low. The low/reverse clutch holds first in that range, so if manual low pulls cleanly but Drive feels like neutral on take-off, the sprag is the likely cause. If the slip continues into second, third and fourth, look at the 1-2-3-4 clutch and its feed circuit instead.
Not directly. The sprag has no sensor or solenoid, so there is no sprag code. The module may log a gear ratio fault if the slip is bad enough, but many trucks show only the driving complaint.
Inspect and replace the race if it is pitted or polished, and replace the low/reverse frictions and steels if they show heat. Most rebuilders also check the 3-5-R drum welds and the sun shell while the geartrain is out.
Do not assume it does. The 6L80 and 6L90 use dimensionally different geartrain parts, and the aftermarket sells separate sprag rebuild kits for each. Match your old part or send us your VIN.
Refill with Dexron VI, check the level hot with the engine running, then reset the adaptive values and run the fast learn with a capable scan tool so the shifts and launch are relearned.
