GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

Hard shifting in reverse can be diagnosed easily. You should perform a static shift and dynamic shift test. Many other simple factors could occur such as insufficient fluid, excessive fluid or even the wrong transmission lubricant. A misaligned transmission can also cause hard shifting as well as a worn or defective clutch, binding of the shift control. Many internal components can also play a factor in hard shifting such as the front bearing retainer loose or cracked, synchronizer worn, damaged or improperly assembled. A failure to fully depress the clutch pedal when shifting will cause hard shifting in reverse.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks for air in the hydraulic lines, this will also cause the transmission to hard shift in reverse.

  2. This step checks for a faulty shift tower.

  3. This step checks for a faulty or worn clutch pressure plate or clutch driven plate.

Step

Action

Yes

No

DEFINITION: The transmission does not shift smoothly into reverse gear.

1

Did you review the manual transmission symptom operations and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Manual Transmission

2

Test the clutch pedal travel. Refer to Hydraulic Clutch Description .

Did you find or repair the condition?

Go to Step 13

Go to Step 3

3

Test for air in the clutch hydraulic system.

Is there air in the hydraulic system?

Go to Step 4

Go to Step 5

4

Pump the clutch pedal 25 times.

Does the transmission still shift hard?

Go to Step 5

System OK

5

Inspect the transmission shift tower for binding.

Did you find and repair the condition?

Go to Step 13

Go to Step 7

6

Replace the transmission shift tower. Refer to Shift Tower Replacement .

Did you find and repair the condition?

Go to Step 13

Go to Step 7

7

Inspect the transmission for the correct type transmission fluid. Refer to Lubrication Specifications .

Did you find and repair the condition?

Go to Step 9

Go to Step 8

8

Drain and refill the transmission with the correct type fluid. Refer to Lubrication Specifications .

Did you find and repair the condition?

Go to Step 13

Go to Step 9

9

Remove the transmission. Refer to Transmission Replacement .

Inspect the clutch pressure pate and/or clutch driven plate.

Is the clutch pressure plate and/or clutch driven plate worn or faulty?

Go to Step 10

Go to Step 11

10

Replace the clutch pressure plate and/or clutch driven plate. Refer to Clutch Assembly Replacement in Clutch.

Did you find and repair the condition?

System OK

Go to Step 11

11

Disassemble the transmission. Refer to Transmission Disassemble in all the Transmission sections.

Inspect the transmission for an internal binding, possibly caused by one of the following:

    • Shift forks
    • Selector plates
    • Synchronizers

Is there internal binding?

Go to Step 12

--

12

  1. Replace worn or damaged components as necessary.
  2. Install the transmission. Refer to Transmission Replacement .

Did you find and repair the condition?

Go to Step 13

Go to Diagnostic Aids

13

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1