GM 4L80E Transmissions
This transmission is similar to the TH400 except that it is electronically controlled and has an overdrive. This transmission does not use a reluctor ring like the 4L60E. The 4L80E transmission is normally equipped with an internal reluctor ring on both the transmission input shaft and output shaft. The computer takes both of these readings in for the proper shifting and operation of this transmission. We have always ignored the reluctor ring requirement for this transmission since it is internally regulated. We now know that the rear reluctor ring is not always installed into the transmission. The basic rule of thumb is 4WD transmissions up to 1996 should have a rear reluctor ring in the main transmission case. All 2WD transmissions should have the rear reluctor in the main transmission case. The 1997 & newer 4WD 4L80E transmissions have a sensor provision; however, the reluctor ring in the transmission is left out. The tailhousing bolt pattern is the same as the TH400, but indexed with a different diameter.
There are several lengths of the stock 2WD transmission output shaft, but only one length of the 4WD. The 1st gear ratio is 2.482; 2nd 1.482; 3rd 1.1, and a 4th gear ratio of .75. This transmission was designed by GM to replace the GM TH400 transmission. Like the TH400, the 4L80E has a 32 spline output shaft.
Forward Speeds .... 4
Dates Produced ....1991 - 2003
Manufacturer .... General Motors
Case Length .... 26.00
Bellhousing Length ... Integral
Over All Length .... 26.00
Case Material ... Aluminum
Output Shaft Spline .... 32
1st Gear Ratio .... 2.48
2nd Gear Ratio .... 1.48
3rd Gear Ratio .... 1.00
4th Gear Ratio .... .75
Reverse Gear Ratio ....2.08
Transmission Weight ....255
Max Engine Torque ....440
Fluid Type .... Dextron VI
Fluid Capacity .... 6.3 Qts
Gross Vehicle Weight Rated ....18,000