GM 4L80E / 4L85E Transmission Tech Info
The 4L80E is GM’s heavy-duty electronic four-speed, built from the 1991 model year for full-size trucks, vans and SUVs. It grew out of the TH400 (Turbo 400), so many clutch and gear-train parts carry over. The 4L85E is the heavier-duty version added in the early 2000s. This page covers identification, early vs late parts, fluid and the kits we sell.
Basics
| Item | 4L80E / 4L85E |
|---|---|
| Model years | 4L80E from 1991 to about 2009 (some of our kits list later years); 4L85E from the early 2000s |
| RPO code | MT1 (4L80E), MN8 (4L85E) |
| Gear ratios | 2.48 / 1.48 / 1.00 / 0.75, reverse 2.07 |
| Shift control | Computer controlled (shift solenoids and a pressure-control force motor) |
| Speed sensors | Input and output speed sensors |
| Pan | 17-bolt pan |
| Fluid | Dexron VI (GM’s current fluid, replacing Dexron III) |
| Fluid capacity | About 7.7 qt pan drop; about 13.5 qt dry after overhaul |
Capacity varies by application and pan, so always finish the fill by the dipstick.
4L80E or TH400?
- A 4L80E has a round electrical connector on the case. A TH400 has no wiring for shifting.
- A 4L80E has an overdrive fourth gear and a longer case.
- Count the pan bolts: 17 on a 4L80E, 13 on a TH400.
4L80E or 4L85E?
The 4L85E is the heavier-duty version of the 4L80E. Many of our listings fit both (for example the TransGo HD2 reprogramming kit, Sonnax Performance Pack, pump gear set and the 4L80E/4L85E bushings). Check the RPO code on the Service Parts Identification label in the glovebox. If yours is a 4L85E, tell us when you order and we will confirm the hard parts.
Early or late? Parts that change by year
| Part | What changes | Shop |
|---|---|---|
| Pump | 1991–1996 pumps have two cooler fittings behind the bellhousing; 1997–2003 have one. 2004–up pumps suit the new-design case. | 1991–1996 · 1997–2003 · 2004–up |
| Filter | Shallow filter 1991–1996; deep filter 1997–up. | Shallow (1991–1996) · Deep (1997–up) |
| Overhaul kit | Seal and gasket kits split between 1996 and 1997. | 1990–1996 · 1997–2011 · Build your own kit |
| Bushing kit | Early and late master bushing kits; 2004–up extension housings take their own bushing. | 1991–1996 · 1997–up · 2004–up extension bushing |
| Clutch modules | Friction modules split between 1995 and 1996 (some brands at 1996/1997). | 1991–1995 · 1996–up · All modules |
| Wiring harness | 1991–2003 and 2004–up internal harnesses differ. | 1991–2003 · 2004–up |
| Solenoids | Five-piece solenoid sets for 1991–2003 and 2004–up. | 1991–2003 · 2004–up |
| Planets | Early and late planets use different gear heights (.710″ vs .795″); each listing gives its years. | Front, early · Front, 1996–up · Rear, 1999–2009 |
| Speed sensors | The same sensor serves input and output on all years. | ISS/OSS sensor set |
Common kits and upgrades
- Shift and valve body: TransGo shift kit, TransGo HD2 reprogramming kit, Sonnax Sure Cure kit (tooling required), Superior shift correction kit and the actuator feed limit valve repair kit.
- Clutches: Raybestos Stage-1 module (1996–up) and Alto Red Eagle module (1997–up).
- Input shaft: heavy-duty input shaft, 300M steel shaft and the Sonnax heavy-duty shaft for high-horsepower builds.
- Servos: reverse servo Extendo pin and the Sonnax externally adjustable low/reverse servo kit.
- Service: Farpak pan gasket, filters above, and torque converters.
Related pages
← GM Transmission Info · Shop 4L80E / 4L85E parts
Questions about your 4L80E? Call (844) 298-6404, Monday–Friday 8–5 Eastern, or email sales@globaltransmissionparts.com with the year, vehicle and case tag numbers.