Supplier location Expand
Part type Expand
Application Expand
Brand Expand
Condition Expand

3T40 Transmission parts

TH125, TH125C

Transmission general data

Number of gears Transmission Type Drive Torque (Nm) ATF (full capacity) L ATF (change) L ATF type (recommended)
3 AT FWD 250 8,5 3,8 Dexron III

The 3-speed automatic transmission GM 3T40 named as Turbo-Hydramatic 125C was installed on FWD cars with engine capacity from 2 up to 3.1 liters. The first modifications of this transmission did not have the torque converter, later versions (1995) had an electronic control and letter E was added to a new name GM 3T40E. The most significant modification was introduced in 1984. Since then sets of gaskets and seals have not been changed.

What are you looking for?

Overhaul Kit | Friction Kit | Friction | Steel Plate | Steel Kit | Band | Solenoid Kit | Solenoid EPC | Solenoid TCC | Pump | Shaft | Drum | Valve body | Torque converter | Hub | Piston | Piston Kit | Planetary Gear | Filter | Gasket | Bushing | Seal | Bearing | Pressure Plate | Stator | Differential | Retainer | Inhibitor Switch | Instruction manual | TOOLS & ACCESORIES | Sensor

Which cars run with this gearbox? CLICK

Technical issues and repair guidelines

The GM 3T40 is a reliable, simple transmission that operates over 300 thousand kilometers. It served as a prototype for the 4-speed family 4T40E -4T60E.This transmission rarely gets in repair services. The main spare parts ordered for repair of this transmission are the repair kit of gaskets and seals (Overhaul kit) or a complete Masterkit (with clutches and seals).


To comment on a complete paragraph, you can hover over the text - then the dialogue icon with "+" sign will appear at the end of the line. Click the icon to leave your comment.

To comment on a part of the text, you can select a part of the text with your mouse - and then the comment options will appear (allowing you to also share a part of the text on social network pages)

Share this page with your friends