ATSG Allison 1000 2000 Gen 1 2 3 4 Transmission Rebuild Repair Overhaul Manual

Description

Allison 1000 & 2000 Series Transmission Rebuild Manual: Generations 1 - 4
This manual will cover the dis-assembly, rebuild of all components, and finally the re-assembly of both the 1000 and 2000 Series units.
This manual is the most current, revised edition.
Beginning at the start of production for the
2000 model year
, General Motors introduced two new Allison Automatic Transmissions referred to as the 1000 Series and the 2000 Series, for Light-Duty
(8600-19850 GVW)
and Medium-Duty
(19850-3000 GVW)
Commerical Trucks.
The 1000 and 2000 Series Transmissions both have helical cut planetary gear systems to minimize noise concerns and come in two different gear ratio configurations. The 1000 Series uses closer steps to improve the shift quality that we now expect from an Automatic Transmission. The 2000 Series uses wider steps to accommodate the greater vehicle weights associated with the 2000 Series. The gear ratios for
both
of the new units are show in this Manual
.
The 1000 and 2000 Series Transmissions have a Park position, Reverse, Neutral and
FIVE
forward speeds with
5th
gear being
overdrive
, and are completely
electronic shift controlled
.  Notice that the standard
GM
case connector has been utilized, and the Park/Neutral switch is exactly the same switch used currently on the
THM 4L60E
Transmission. Two different bottom pan configurations are also provided to make these units more versatile. The 1000 and 2000 Series Transmissions utilize five clutch packs
(No Bands, No Freewheels)
to obtain the five forward gears and reverse.