GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2001 🢒 Firebird 🢒 Transmission/Transaxle 🢒 Manual Transmission - M49 🢒 Transmission Shifts Hard

Diagnostic Aids

Hard shifting can be diagnosed easily. You should perform a static shift and a dynamic shift test. Many other simple factors could occur such as insufficient fluid, excessive fluid or even the wrong transmission fluid. A misaligned transmission can also cause hard shifting as well as worn or defective clutch or binding of the shift control. Many internal components can also play a factor in hard shifting such as a 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.

Test Description

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

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

    2.

  2. This step inspects for a faulty shift control.

    3.

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

Step

Action

Yes

No

DEFINITION: The transmission does not shift smoothly or without difficulty into another 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.

Is there sufficient clutch pedal travel?

Go to Step 4

Go to Step 3

3

Remove any clutch pedal restrictions.

Did you find and repair the condition?

System OK

Go to Step 4

4

Test for air in the clutch hydraulic system.

Is there air in the hydraulic system?

Go to Step 5

Go to Step 6

5

Bleed the air from the clutch hydraulic system. Refer to Hydraulic Clutch Bleeding in Clutch.

Did you find and repair the condition?

System OK

Go to Step 6

6

Inspect the transmission shift control for binding.

Is the transmission shift control binding?

Go to Step 7

Go to Step 8

7

Replace the transmission shift control. Refer to Shift Control Assembly Replacement .

Did you find and repair the condition?

System OK

Go to Step 8

8

Inspect the transmission for the correct type transmission fluid.

Is the correct type fluid being used?

Go to Step 10

Go to Step 9

9

Drain and refill the transmission with the correct type fluid. Refer to Transmission Oil Drain and Fill .

Did you find and repair the condition?

System OK

Go to Step 10

10

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

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

Go to Step 11

Go to Step 12

11

Replace the clutch pressure plate and/or clutch driven plate. Refer to Clutch Pressure Plate and Clutch Driven Plate in Clutch.

Did you find and repair the condition?

System OK

Go to Step 12

12
  1. Remove the transmission. Refer to Transmission Replacement .
  2. Inspect the transmission for an internal bind possibly caused by one of the following:
    3. • Shift forks
    • Selector plates
    • Synchronizers

Is there an internal bind?

Go to Step 13

--

13
  1. Replace worn or damaged components as necessary. Refer to Transmission/Transaxle/Transfer Case Unit Repair Manual.
  2. Install the transmission. Refer to Transmission Replacement .

Did you find and repair the condition?

Go to Step 14

Go to Diagnostic Aids

14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 1