GM 4T80-E MH1 Front Wheel Drive

Cadillac Seville
Cadillac De Ville
Oldsmobile Aurora


Description: Four speed front-wheel-drive, electronically controlled, automatic overdrive transaxle with viscous torque converter clutch.


Fluid Recommendations Maintenance Tips  Positraction for FWD    

Gear Ratio

1st: 2.960 2nd: 1.626 3rd: 1.000 4th :0.681 and Reverse: 2.130
  7-Position Quadrant:
P, R, N, OD, 3, 2, 1
Fluid Additives Overhaul Tips Torque Converter Installations Tips

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 4T80-E back in top running order. This is an abbreviated list and other parts are available. If you need something that is not listed just let us know.
Part Number    






TM4T80E     Technical Manual       $38.97
Rebuilder Box Kit            
MRK4300-S     Master Rebuilder Kit (w/o Steels, includes all filters and O/D Band)   1993-94   $659.60
MRK4300B-S     Master Rebuilder Kit (w/o Steels, includes all filters and O/D Band)   1995-On   $597.90
Steel Plate Sub-Kits            
K4300-9     Steel Plate Kit   1993-94   $65.90
K4300B-9     Steel Plate Kit   1995-On   $71.60
43720     Low & Reverse   1993-On   $98.70
TRSB94024A     Overdrive (Front, Flex)        $17.37
TRS94030A     Bushing Assortment Kit   1993-On  


Thrust Washers            
TRS94200     Washer Kit 8 washers includes 3 selectives   1993-On   $111.97
K43900-4     Piston Kit   1993-94   $319.60
K43900B-4     Piston Kit   1995-On   $319.60
TRSA94652A     Intermediate Clutch Sprag (16 Elements)   1993-On   $84.54
TRSA94658A     Input (Forward) Sprag (36 Elements)   1993-On   $65.30
TRSA94654A     Low Roller Clutch (18 Rollers)   1993-On   $92.60
43888     Drive Chain (7/8" Wide -42 Rocker Links)   1993-On   $103.90
TRSA94700B     Drive Chain (1" Wide - 42 Rocker Links)   1993-On   $147.80

The following electronic components may or may not be required. The best way to determine this is by check/consulting computer code(s) or electronic scanner results.
Electronic Components            
K43871   1   "A" & "B" Shift Solenoid Kit (Updated)   1993-96   $107.96
51873   1   TCC (PWM) Solenoid   1993-98   $35.30
51879   1   Force Motor (EPC) Solenoid   1993   $98.10
33879A   1   Force Motor (EPC) Solenoid   1994-On   $92.16
43877   1   Pressure Switch Manifold   1993-On   $51.10
Torque Converters For this series transmission there are MANY different possible torque converters (not all listed here). 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 possibilities are:
Part Number   Vehicle Identification       Price  
C60   Fits 1993-Up Oldsmobile Aurora   Code: 8683441, 8689991, "441" sticker   $141.00 plus core deposit c60torqconv_large.jpg
C61   Fits 1994-Up Cadillac   Code: 8683440, 8689990, "440" sticker, note: The C61 may have an alternate pad type. Either style will interchange.   $141.00 plus core deposit c61torqconv_large.jpg

Miscellaneous Information and Specifications
Engine Range:
4.0L - 4.6L
Maximum Engine Torque:
305 lb-ft
Converter Size:
265mm (reference)
(Diameter of torque converter turbine)
Maximum Shift Speeds:
1-2 6500 rpm
2-3 6500 rpm
3-4 6500 rpm
Maximum Gearbox Torque:
461 lb-ft
Fluid Capacity (Approximate):
Bottom Pan Removal: 6.6L (7.0 qt)
Dry: 13.2L (14.0 qt)

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.
redlineatf_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:

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 temperature 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.

Overhaul Tips

Before you tear into the transmission, we suggest you first study the troubleshooting/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 transmission, 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!

The difference between stator design, look inside the converter at the larges set of spline's (stator shaft spline's). If the spline's 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 occurred 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 surface. Grinding off on thread length from all lockup converter bolts is recommended to avert this type of failure.

In addition to GM Cadillac De Ville, Seville and Oldsmobile Aurora automatic transmission/transaxle overhaul kits and repair parts we offer free technical support to assist you in solving your automotive problems.