6L90 Clutch Drum 2006, new and ready to install. Fits the 6L90. Ships fast from the USA.
This listing sits in our 6L90 clutch drum section because every piece in it lives inside the clutch housings, but it is not a drum. What you get is the ACDelco set of five molded clutch pistons and retainers shown in the photo: rubber-sealed steel pistons, a balance dam with its bonded seal, and the toothed return ring. It is for the builder who has a 6L90 apart on the bench from a Silverado or Sierra 2500HD or 3500HD, an Express or Savana van, or an HD Suburban, and has found pistons with hard, cracked or lifting rubber. If your drum itself is cracked at the weld, you need a housing, not this set; see the fitment notes below.
The 6L90 shifts without bands. Each of its five clutches (1-2-3-4, 3-5-Reverse, 4-5-6, 2-6 and Low/Reverse) is squeezed by a hydraulic piston, and every gear change is one piston exhausting while another fills. On a molded piston the sealing lip is vulcanized straight to the steel stamping, so the seal and piston are replaced as one part. The rotating clutches also carry a balance dam on the back side of the piston. Oil trapped behind the dam cancels the centrifugal pressure that builds in a spinning drum, which keeps the clutch from dragging or releasing late at highway speed. When that rubber ages in hot fluid it shrinks and stiffens, the piston bleeds apply oil, the pack fills slowly and clamps soft, and the computer keeps adding pressure to make up for it until the frictions burn.
A 6L90 apply circuit can leak in several places, and the piston is only one of them. Gears Magazine traces many clutch failures to the stator support, which feeds the 1-2-3-4, 3-5-R and 4-5-6 clutches, and to the gaskets around it. Air-check each clutch with the unit apart: a piston that hisses around its lip, or one that will not stroke and hold, is the problem; a leak at the sealing rings or support points elsewhere. Our 3-5-R clutch failure guide covers the no-Reverse path and the cracked housing, and the 6L90 common problems guide sorts the other failures by symptom.
The set is listed for the 6L90 from 2006. The 6L80 entered production for the 2006 model year and the 6L90 followed in 2007-and-newer heavy-duty trucks and vans, and many piston part numbers carry across both units. Lay the five pieces next to the ones you remove and match diameter, shape and seal position before you install anything. If you would rather we check, send us your year and VIN. If the housing is cracked at the weld, GM bulletin 09-07-30-004J calls for replacing the housing; our 6L90 1-2-3-4 / 3-5-R clutch drum covers that. Every other part for the unit is on the 6L90 parts page.
| Fits | 6L90 2006 |
| Part type | Clutch Drum |
| Condition | New |
| Brand | ACDelco |
| Ships | From the USA |
| Warranty | 1-year |
No. It is listed with our clutch drums, but it is a five-piece ACDelco set of molded pistons and retainers that install inside the drums and case. Order a housing separately if yours is cracked.
It is listed for the 6L90 from 2006 and many pistons are shared with the 6L80. Compare each piece to the one you remove, or send us your year and VIN before you order.
Air-check each clutch with the unit apart. Air escaping around the piston lip points to the piston; air escaping at the sealing rings or stator support points to those parts instead.
The frictions and steels of any pack that slipped, all sealing rings and gaskets, and the filter. A master rebuild kit covers the soft parts.
Dexron VI only. After the rebuild, clear the transmission adaptive values with a scan tool and complete the adaptive learn drive.
