GTO Clutch Pressure Plate Bolt Torque Spec and Slave Cylinder Change - kw 5.7 6SP cold crank fifth first fourth grind hard information inoperative manual M12 operation pedal performance power reverse
| Subject: | GTO Clutch Pressure Plate Bolt Torque Spec and Slave Cylinder Change |
| Models: | . |
The following diagnosis might be helpful if the vehicle exhibits the described symptoms in the PI.
Condition/Concern:
If a customer complaint on a manual transmission GTO with "hard to select gears" is received, please follow the process listed below to diagnose and correct: This condition may be caused by one of two concerns which have been noted prior.
| • | Customers may complain of a spongy clutch pedal feel and disengagement point close to the floor - vehicle on or off, hot and cold (most noticeable cold first thing in the morning). This may be caused by air in the system and bleeding should result in satisfactory disengagement/engagement feel and function. |
| • | Customers may state they have difficulty selecting all gears, reverse being the most noticeable. They may feel a spongy clutch pedal, only when vehicle is running. When vehicle is turned off, the clutch pedal feels normal. This is the main difference between air in the system and loose pressure plate bolt concern. The disengagement point will be close to the floor. |
Recommendation/Instructions:
- Check the disengagement and engagement point of the clutch. Pushing on the clutch pedal, the disengagement point should be located approximately 50 mm off the floor.
- If disengagement is very close to the floor (UNDER 30 mm), there is the potential that the pressure plate bolts have worked loose and/or there is air in the clutch slave cylinder system.
- Whether you have bled the slave cylinder or re-torqued the clutch assembly, it is important that the transmission be evaluated to confirm that no synchronizer damage has occurred as a result of the poor clutch disengagement. Replace or repair as required.
- The disengagement point must be evaluated following any service performed.
To establish whether the pressure plate bolts have worked loose, check the breakaway torque of the pressure plate to flywheel bolts (50 +/- 10 NM was the original assembly torque). If less torque than this is required to loosen the bolts, torque the clutch pressure plate bolts to 70 Nm/52 lb/ft. There is a high probability that the clutch will be fully functional following a re-torque. If torque is found to be well under 50 Nm, it is suggested the clutch disc be replaced for Customer Satisfaction. If the clutch feels spongy, like the system may have air in it, the system must be thoroughly bled with Dot 4 hydraulic fluid to eliminate this concern. Vehicles built prior to 10/8/03, VIN 4L181535 should have clutch slave cylinder part #92067460 installed and bled with Dot 4 fluid, if they have a spongy clutch pedal. The clutch slave cylinder bleed fitting is difficult to view without a mirror but it is accessible through a hole above the transmission in the bell housing. An alternative bleeding method is to use the vacuum bleed procedure from TSB 01-07-31-002.
Note: When servicing the flywheel and pressure plate you may note that they are dished. The outer surface of each makes initial contact with the clutch disc and subsequently the entire surface is engaged once the clutch pedal is fully released. This is normal for this assembly. Donot replace components for this concern. This is a torque management technique that is employed as a result of engine output potential.
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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.
Models:
(2004 Pontiac GTO)
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