Allison 1000 Shift Solenoid Kit, 7-Piece, 1999-2005 Duramax

This is a seven-solenoid set for the early 5-speed Allison 1000/2000 (LCT1000) used behind the 6.6L Duramax in 1999-2005 GM pickups. It cross-references OE numbers 8683167, D116420A, 29533074, 29533075 and 29536833 and uses the same mounting and connector layout as the original units.

These are professionally refurbished solenoids: disassembled, cleaned, worn internals replaced, and each kit is pressure and signal tested before it ships. That makes it a practical option for a truck that is shifting late, flaring, slipping between gears or setting pressure control and shift solenoid codes, without paying new-OE pricing for all seven.

Service notes: the solenoids live on the control valve body under the pan. Drain the fluid, remove the pan and filter, unplug and unbolt the solenoids, and inspect the valve body for debris before installing the new set. Refill with TranSynd or an approved Allison TES-295 fluid, clear codes and run a relearn so the TCM adapts to the new solenoids.