GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Sierra Denali 🢒 Transmission 🢒 Manual Transmission - Tremec 5-Speed (TZ0) 🢒 Transmission Shifts Hard into Reverse

Diagnostic Aids

Hard shifting in reverse can be diagnosed easily. You should perform a static shift and dynamic shift test also. Many simple factors could occur such as, excessive clutch pedal free travel, insufficient fluid, excessive fluid, or 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, the synchronizer worn, damaged, or improperly assembled. A failure to fully depress the clutch pedal when shifting causes hard shifting in reverse.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step inspects for air in the hydraulic lines, which also causes the transmission to shift hard in reverse.

    2.

  2. This step inspects for a faulty shift control.

    3.

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

Step

Action

Yes

No

DEFINITION: The transmission does not shift smoothly or without difficulty from one gear to another.

1

Did you review the Symptoms - Manual Transmission operations and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Manual Transmission

2

Inspect the clutch pedal travel.

Is there sufficient clutch pedal travel?

Go to Step 3

Go to Step 4

3

Remove any clutch pedal restrictions.

Does the transmission shift hard in reverse?

Go to Step 4

System OK

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 .

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 tower. Refer to Transmission Control Replacement .

Did you find and repair the condition?

System OK

Go to Step 8

8

Inspect the transmission for the correct type of transmission fluid.

Is the correct type of transmission fluid being used?

Go to Step 10

Go to Step 9

9

Drain the transmission fluid and fill the transmission with the correct type of fluid. Refer to Transmission Fluid Replacement .

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 Assembly Replacement .

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 components:
    3. • Shift forks
    • Selector plates
    • Synchronizers

Is there an internal bind?

Go to Step 13

System OK

13
  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 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