Allison valve body for 1000, remanufactured and ready to install. Ships fast from the USA.
2004 and 2005 Chevrolet Silverado and GMC Sierra 2500/3500 HD trucks running the Allison 1000 with the Duramax diesel use a short-lived transitional valve body casting - 7 solenoids like the later units, but still routed through a single external transfer tube before Allison moved the plumbing fully internal in 2010. If your truck in this two-year window is shifting harsh, slipping, flaring between gears, or has thrown a limp-mode code, this remanufactured valve body is built for that specific casting, bench-tested with the correct updates before it ships.
Allison launched the 1000 Series in 2001 with a 6-solenoid valve body; by 2004 the casting had moved to 7 solenoids with a single external tube, a design Allison kept for one more revision in 2006-2009 (with 2 tubes) before going tubeless starting in 2010. Transmission Digest's casting-identification writeup on this family documents the casting and spacer-plate changes across these early years, which is exactly why a 2001-2003 unit, a 2004-2005 unit and a 2006-2009 unit are three different parts even though they look similar in a parts diagram. The valve body itself routes line pressure through precision bores and spool valves to apply each clutch and band, and the 7 solenoids on this casting are what the TCM fires to time every shift.
Pull codes and note which shift is affected before you spend anything - a sticking E-shift valve throws P0872 and a failsafe condition, while worn F-trim sleeves show up as P0741 and TCC surge or slip, so the stored code tells you a lot before you even pull the pan. Our Allison 1000 valve body testing guide covers the hydraulic checks, and our limp mode guide lists the other failure points - wiring, TCM, speed sensors - worth ruling out first on a truck this age.
This valve body is built for the 2004-2005 Allison 1000 - the 7-solenoid, 1-tube casting - as installed in Chevrolet Silverado and GMC Sierra 2500/3500 HD trucks with the Duramax. It is not interchangeable with the 6-solenoid 2001-2003 casting or the 2-tube 2006-2009 casting; match your solenoid count and tube routing against the listing photos, or send your year and VIN and we will confirm. The same casting also shows up on medium-duty 2000 Series trucks of this same vintage. See the full Allison parts collection for every other year range we stock.
Change the fluid and filter at the same time as the valve body swap so debris from the old unit does not circulate into the new one - a deep pan kit with filters is sized for this platform. Torque the bolts in sequence to spec, and refill with TES 668 full synthetic ATF or TranSynd, Allison's approved fluid for the 1000 Series and backward compatible with the TES 295 these trucks originally shipped with; a 3-gallon TranSynd 668 covers a full service with enough left over to top off. On a truck this age, also check the internal wire harness for chafing, since a cracked harness on a unit this old throws the same solenoid codes as a failing valve body. Clear codes and run the TCM's adaptive relearn after the swap.
| Transmission | Allison |
| Year Range | 1000 |
| Condition | Remanufactured / updated |
| Shipping | Ships from the USA |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Allison moved from 6 solenoids to 7 and added a single external transfer tube starting with the 2004 model year. This listing is that 7-solenoid, 1-tube casting.
No - 2006-2009 trucks use a 2-tube casting, and 2010-up trucks use a tubeless casting. Order the correct year-specific version, or send your VIN if you are unsure.
Harsh or flared shifts (especially 2-3 or 3-4), slipping between gears, torque converter clutch slip or shudder, and limp mode with a stored solenoid, pressure or ratio code.
TES 668 full synthetic ATF or TranSynd, Allison's approved fluid for the 1000 Series, backward compatible with the TES 295 these trucks originally used.
Yes - clear codes and run the TCM's adaptive relearn so clutch fill and shift pressure are retimed against the new valve body.
Yes - the Allison 2000 Series used in Kodiak and TopKick medium-duty chassis shares this casting for the same 2004-2005 model years.
