Transmission

Transmission
The OEM transmission is a GM 4L30-E. It is a computer-controlled overdrive transmission, using the 'optional' gear ratios:
 * 2.86:1 1st gear
 * 1.62:1 2nd gear
 * 1.00:1 3rd gear
 * 0.723:1 4th gear
 * 2.00:1 reverse

Transfer case ratios - (:1) High: 1.00 Low: 2.48

Axle gear ratios - (:1) Front: 4.30 Rear: 4.30

Hard Shifting
Often caused by a failing Mode Switch. This will also cause the PRNDL indicator to show the wrong gear, and may store a ???? code in the OBDII diagnostics, although the check-engine light does not light.

May also be caused by a clogged transmission filter.

May be caused by a lack of transmission fluid.