4L80E Hydra-Matic Transmission (MT1) General Motors

Overhaul kits and parts.

We provide a large inventory selection for 4L80E automatic transmission overhaul kits, parts including steels, kits, solenoids, filters, solenoids. This wide selection of parts are used in the GM 4L80E automatic transmission in GM C and K series pickups, Chevy vans including the express, Suburbans, School Bus, Motor Home, GMC Sierra and Savan's. In addition to these kit we also supply torque converters, fluids, problem prevention kits and in most cases we can supply good take out hard parts and save you some money.

Free infomation is provided on parts illustrations, maintenance tips, overhaul tips and assistance in identifying just what automatic transmission you have in your vehicle. In addition a factory description and ratio information is available. 

Troubleshooting/Overhaul Manual

These manuals are typically 50 to 85 pages and contain both troubleshooting information and data to support overhaul, such as electronic data, illustrations and specific procedures and specifications. These are professional shop manuals which will give you the capability to diagnose problems, and evaluate repair options. If you decide to have your transmission overhauled at a local shop you will be armed with detailed knowledge of problems and potential fixes. This information should allow you to get the best deal, Always compare pricing for labor. If you supply the parts and ask for warranty in the end you will save money.

Fluid Recommendation: Red Line high-Temp ATF Our Red Line high-Temp ATF --is a synthetic GL-4 gear oil for use where Dexron III is recommended. A higher viscosity allows optimal operation at 70 degrees higher temperature, providing better torque converter efficiency. Perfect for heavily-loaded vehicles. Superior stability allows high-temperature operation without varnishing valves and clutches. Recommended for use after overhaul, mixing with existing fluid is not recommended!

Red Line high-Temp ATF your cost $11.95 qt.

Typically contains gaskets and rubber kit, sealing rings, metal/rubber clad seals, friction plates, steel plates* , front and rear bushings, filter and where applicable Band* and/or Modulator*.

*not included if listed separately

Maintenance Tips

Regular maintenance cycles and continued checking of fluid levels is critical to the life of your transmission. Operating temperature is the single most critical parameter effecting the life of the transmission. Keep the temperature down and fluid fresh helps the units typically last a very long time under normal driving conditions (no teenagers involved). We can supply a couple of aftermarket products to help you get the most out of your transmission:

Auxiliary Transmission Oil Cooler.

The Truco part number LPD4451 is an excellent auxiliary oil cooler to provide additional cooling capacity. The kit includes all parts required to mount the unit and connect to existing cooling lines. This is a typical do it yourself project. The unit typically mounts in front of the radiator. Your cost on this transmission life saving product is $64.94 plus shipping and handling.

Fluid Additive

Generally we don't recommend additives but we have found that the Lubegard "Automatic Transmission Protectant" at only $13.93 + S&H can:

Deep Transmission Pan

These high quality deep transmission pans can signifanctly improve the cooling of your 4l80E transmission. These pans are manufactured using heavy wall finned aircraft aluminu housings for additional cooling capability. They allow for an additional 4.5 quarts of fluid. The transmissions are easier to check and service these advance pans and offer the following features:

Always consult and follow owners manual for maintenance intervals and requirements.

Before you tear into the transmission, we suggest you first study the troubleshootin/overhaul manual, add a bottle of our "Automatic Transmission Protectant" and put a few miles on the vehicle. This just might free valves and governors that are possible stuck in valve bodies. Be sure to get computer trouble code(s), see owners manual for technique to acquire malfunction codes. This will be a great assistance in diagnosing possible problems.

Twenty-One Steps to Successful Transmission Repair:

1) Do your research locate any technical bulletins pertaining to your transmission, ask your dealers parts department for bulletins.

2) Clean the entire transmisssion, including the valve body.

3) Check pump, valve body and case for warpage.

4) Flat file pumps, valve bodies, and cases. Just a few strokes with the file to knock off high spots and handling burrs.

5) Check all pump gear clearances.

6) Check planet pinion end play and side to side motion.

7) Soak all planet assemblies.

8) Soak all friction materials for 15 - 30 minutes.

9) Make sure all steels are in usable condition or replace. Do not sand or tumble steels when used against High Energy friction materials.

10) Inspect all surfaces upon which a band will ride.

11) Replace all rotating oil control rings.

12) Check all oil control rings and rubber products in the bores for proper fit.

13) Check all major support bushings and bushings that control lub oil.

14) Pre-lubricate all bushings and thrust washers.

15) Pre-lub pumps.

16) Pre-fill torque converter.

17) Use available manuals to ensure proper specifications and clearances.

18) Set correct clutch and band clearances.

19) Take the time to set the total end play.

20) Use a torque wrench on all pumps and valve bodies.

21) Always double flush the cooling and cooling return lines to the radiator to remove particles trapped there.

Take your time, take your time, take you time!

Torque Converter Information

Failue modes for torque converters manifest themselves in different ways, slow failue, i.e. loss of power over time, instant failure, i.e. input shaft spline failure. Following is a short list of problems, prossible causes:

The difference between stator design, look inside the converter at the larges set of splines (stator shaft splines). If the splines are split then the unit has a dual element stator. Do not interchange single element and dual element converters.

Torque Converter Installation/Preparation

Many torque converter problems can be avoided with proper preparation:

1) Pre-thread converter bolts by hand to make sure there is no sign of stripped threads.

2) Check and clean crankshaft thoroughly. Change crank spacer (if applicable).

3) Use 320 grit sandpaper or Emory cloth to remove any metal shavings on crankshaft.

4) Check converter for any damage that may have occured during shipping.

5) Pre-fill converter with a minimum of (1) quart of transmission fluid.

6) Clean all paint off the pilot using 320 grit emory cloth.

7) Apply grease, not transmission gel, on the pilot.

8) Check flexplate for cracks and be sure there is no more than .006" run out.

9) Make sure all engine dowel pins are in place and clean.

10) Make sure all electrical ground straps are properly connected.

11) Never, Never use an impact gun to install torque converter bolts. Driving a bolt into the converter cover will create a dimple on the lockup apply surface. Lockup clutch failure will occur when the lockup piston applies against and uneven surace. Grinding off on thread length from all lockup converter bolts is recommended to avert this type of failure.