GM Turbo 400 Automatic Transmission Rebuild Kits.

Turbo 400 Automatic Transmission Rebuild Kits, Supply the parts and save money!


TH400,  Hydra-Matic Transmission 3L80 (M40) 3 speed


Considering overhauling your Chevrolet transmission or just need GM TH400 need parts? We provide a large inventory selection for TH400 automatic transmission overhaul kits, parts including steels, kits, solenoids, filters, solenoids. This wide selection of parts are used in the GM TH400 automatic transmission in GM model years 1965 to 1990 Chevy light duty trucks and passenger cars starting in 1965.. In addition to these kits 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.


Parts Illustration

Troubleshooting/Overhaul Manual
Maintenance Tips

Overhaul Tips
Remanufactured Automatic Transmissions

What transmission do I have?

3 speed rear wheel drive, transmission .

1965-1990 GM Light Duty Trucks
1965 - 197? GM Passenger cars.
Fluid Recommendation  
Considering overhauling your transmission? The following list of parts are recommended by our remanufacture as being the parts that are most probably needed to put your 4L80-E back in top running order. This is an abbreviated list and other parts are avialable. If you need something that is not listed just let us know.

Part Number

Qty Req




TM400   Troubleshooting/Overhaul Manual 1964-1992


MRK-3400B-S   Master Overhaul Kit (w/o steels) 1968-1992




Steels Kit 1968-1992




Rear Band 1964-1992




Thrust Washer Kit (w/o Selectives) 1964-1992




Thrust Bearing Kit 1964-1992




Complete Bushing Kit 1964-1992




Intermediate Sprag Assembly 32 element (16 element is avail) 1964-1992




Intermediate Roller Assemby 1964-1992




Low Clutch Roller Assembly 1966-1992




Governor Gear & Pin Kit 1964-1992




Detent Solempod Sjpt Wore 1964-1992




Connector Switch 1 Prong 1968-1992




Reverse Boost Valve and Sleeve (addresses poor line rise and shift complaints 1964-1992


External Cooler Auxilary      


LPD4589   Long "True Cool" Lower pressure Drop Cooler 8" x 11" x 1.5" Complete kit. Remove the heat extened the transmissions life.  



The following components are available to enhance Shifting  

Part Number

Qty Req






Shift Correction Kit  


Torque Converter ---------- Torque Converter Problem & Information

For this series transmission there are MANY different possibile torque converters). When rebuilding your transmission it is always recommended that you change the torque converter. When ordering the torque converter you must supply the four digit code off of the existing unit (located on a sticker). Some of the possibities are:

torqueconverter_large.jpg Torque Converter Installation/Preparation

Code Order Part Number   Application Price
  GM3   1964-UP; 3 rows of ribs (not trucks or Suburbans 87-up) Low Stall; GM3 and GM8 will interchange, USS thread


  GM8   1964-UP; 3 rows of ribs (not trucks or Suburbans 87-up) Low Stall; Metric thread


  GM6   1964-up; 2 rows of ribs (not trucks or Suburbans 87-up) High Stall; GM6 and GM7 will interchange, USS thread


  GM7   1964-up; 2 rows of ribs (not trucks or Suburbans 87-up) High Stall; GM6 and GM7 will interchange, Metric thread


  GM5   1964-UP; 3 rows of ribs (not trucks or Suburbans 87-up) Low Stall; GM5 and GM9 will interchange, USS thread


  GM9   1964-UP; 3 rows of ribs (not trucks or Suburbans 87-up) Low Stall; Metric thread


  GM4   Variable pitch stator; VP solenoid on front pump, do not interchange with fixed pitch stator converters.


Be sure to use our transmission cooling line flush in order to remove debris. Your cost is $11.88 order Kooler Kleen.
  J8   1977-up Jaguar May have spot welds instead of ribs, High stall stator (1750 stall); furnaced brazed


  TC275-3L   1987-up (retro to 64) Trucks, Suburbans, Motorhomes, Furnace brazed; Allison bearings


  TC275-6L   1987-up (retro to 64) Trucks, Suburbans, Motorhomes, Furnace brazed; Allison bearings


Modified TH 400 torque converters are avaliable*
Heavy Duty 1500-1700 HD   Designed for heavy duty applications with stock stall speeds. Fully brazed turbine & impeller to resist loads. Add $123.00 to above.
Low Stall 1300-1500 RV   Reprogrammed for towing applications and fuel economy. Fully brazed turbine & impeller to resist loads Add $123.00 to above.
High Stall HS   You may use TH350 Non-lockup torque converters to achieve a higher stall. This will require the dual bolt pattern 350/400 f;uwjee;/ Add $123.00 to above.  
We supply only high quality remanufactured torque converters, cost + $50.00 core deposit.
* Modified units are available for: all TH400 converters except the TC275-3L & -6. Note: The TC290 & TC290-3l may be used for extreme duty applications.

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!

Our LubeGard "automatic transmission protectant " is recommended as an additive to improve transmission life and maintenance.

atf_large.jpg Red Line high-Temp ATF your cost $11.95 qt.  
Master Rebuild Kit

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 $54.94 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:

  • Prevent overheating, reducing transmission temperatuare up to 40 degrees F.
  • Extend fluid life
  • Eliminates transmission fluid foaming and oxidation
  • Reduces wear throughout the transmission
  • Elimates clutch chatter and torque converter shudder
  • Softens and modifies harsh shifts
  • Provides for smoother shifting
  • Eliminates objectionable noises during shifts
  • Keeps valves and governors free and frees stuck valves in valve bodies
  • Raises the thermal and oxidative stability
  • Only product that increases the fluids ability to transfer heat
  • Contains no Ash

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

ult and follow owners manual for maintenance intervals and requirements.

Overhaul Tips

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 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 us 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.