Posted: 05/11/10 06:43 PM
I recently purchased a new 2009 Shelby GT500. I love this car except for the clutch engagement chatter. During takeoff from a dead start, the clutch chatters and causes the driveshaft to shudder (creating noise) very similar to when a clutch has been overheated and damaged and (or) needs replacement. It has done this since it was new, I brought it back to the dealer the following day who explained that it was normal, but that I should bring it into the service department to be sure, which I did. They had one of their techs come out to talk to me and explained that it uses a dual disk clutch and that it was normal for a Shelby. He further printed a Ford service bulletin for me that confirmed what he said. I said all of this to say I don’t like it, and apparently others felt the same, because the new GT500’s use a different clutch that is much smoother as stated by several Mustang enthusiast magazines. I don’t race the car or dog it; it’s just my daily driver which I use in traffic everyday to get to work. Can anything be done about this? Shouldn’t Ford accept responsibility for this? Somebody help me because Ford won’t.
Posted: 05/12/10 12:39 PM
I think you might want to have this TSB service performed...
* SHELBY GT500 - CLUTCH DRAG
Publication Date: February 12, 2010
This article supersedes TSB 09-19-11 to remove the production fix date, update the Service Procedure and Part List.
Some 2007-2009 Mustang Shelby GT500 vehicles may exhibit the following clutch/transmission symptoms: hard to disengage or engage 1st and reverse, hard to shift all gears, vehicle creeps with transmission in gear and clutch pedal fully depressed without brake pedal application. These symptoms may be caused by the clutch not disengaging fully when the clutch pedal is fully depressed. This may be due to flywheel distortion caused by excessive heat build-up during unique traffic conditions (example: severe stop/go urban driving, excessive clutch slipping). The clutch system is designed for performance driving conditions.
Follow the Service Procedure steps to correct the condition.
Located at the end of the procedure are Figures 1, 2 and 3 which show the typical appearance of a flywheel and clutch that has been damaged due to overheating of the clutch. Figures 4, 5 and 6 show the typical appearance of a good flywheel and clutch.
This procedure does not apply to or correct the normal characteristics of the twin-disc cera-metallic clutch used in the Shelby GT500 vehicle or normal wear. The twin disc cera-metallic clutch incorporates racing technology to combine a low inertia assembly with a very durable friction material with high torque capability. Depending on your driving technique, the smoothness of how the clutch reacts to clutch engagements may be different from other vehicles that use a single disc clutch system. Also refer to pages 8 and 9 of the GT500 Owner Guide Supplement for additional information.
Normal Operating Characteristics Of The Twin Disc Cera-metallic Clutch
* Clutch chatter/shudder when engaging the clutch.
* Narrow or abrupt engagement point.
* Hiss upon clutch engagement or disengagement.
* Transmission gear rollover noise at idle.
* Gear rattle noise at very low speeds when in 1st or 2nd gear.
* Normal wear.
Diagnosis And Service Procedure Update
Based on engineering analysis of all of the returned transmission components replaced when performing the prior TSBs, it has been determined that the synchronizer assemblies and transmission input shafts do not exhibit any abnormal wear that would require transmission component replacements.
A diagnostic procedure has been developed to confirm that the transmission synchronizers are operating properly and prevent any unnecessary transmission repairs.
Transmission Synchronizer Diagnosis Procedure
The following procedure is to be used to determine if the synchronizer assemblies in the transmission may have been damaged by attempting to operate the vehicle with a dragging clutch.
* Set parking brake.
* Transmission in neutral.
* Start engine and allow it to idle.
* Clutch engaged - pedal fully released.
* Attempt to shift transmission into first gear by firmly pushing shift lever approximately 5-10 lb-ft (22-45 N-m) force for 2-3 seconds.
* If the synchronizers are okay, the transmission will not make any clash or grinding noise. You will not be able to move the gearshift lever into the selected gear (the synchronizer will block out gear engagement) and the engine RPM will decrease slightly.
* Repeat the synchronizer test (Step 5 and 6) on all of the other forward gears.
o If the transmission passes the synchronizer test, the transmission will not require additional service; proceed with clutch/flywheel replacement only. Refer to Clutch Replacement procedure.
o If clash/grinding noise is found when performing the synchronizer diagnostic, the transmission will need to be repaired along with the replacement of the clutch. Refer to Transmission Repair procedure.
* Remove the transmission per 2010 Workshop Manual (WSM), Section 308-03C.
* Remove and replace flywheel per 2010 WSM, Section 303-01C. Discard old bolts and use new bolts.
* Install new pilot bearing per 2010 WSM, Section 308-01.
* Install new clutch disc and plate assembly per 2010 WSM, Section 308-01. Using new bolts.
* Apply a small amount of Motorcraft® PTFE Lubricant to the clutch hub splines per 2010 WSM, Section 308-01.
* Install new clutch slave cylinder and hydraulic line per 2010 WSM, Section 308-02.
* Install the transmission per 2010 WSM, Section 308-03C.
* Refer to Powertrain Control Module (PCM) Reprogramming.
* Remove, drain, disassemble and clean the transmission per 2010 WSM, Section 308-03C.
* Remove and replace input shaft and all synchronizer assemblies per 2010 WSM, Section 308-03C.
* Assemble the transmission per 2010 WSM, Section 308-03C.
* Install the transmission per 2010 WSM, Section 308-03C.
* Refer to PCM Reprogramming.
The PCM must be reprogrammed after the clutch is replaced. Reprogram the PCM to the latest calibration using IDS release 65.07 and higher. This new calibration is not included in the VCM 2010.1 DVD. Calibration files may also be obtained at www.motorcraft.com.
PART NUMBERPART NAMEAR3Z-6375-AFlywheelAR3Z-7B546-AClutch7R3Z-7C391-BTransmission KitXG-8Motorcraft® PTFE LubricantXT-5-QMMotorcraft® MERCON® V Automatic Transmission FluidPM-1-CMotorcraft® High Performance DOT 3 Motor Vehicle Brake FluidXG-1-CMotorcraft® Premium Long-Life GreaseTA-30Motorcraft® Silicone Gasket and SealantTA-25Motorcraft® Threadlock and SealerF6ZZ-7600-APilot Bearing1R3Z-7052-AATransmission Input Shaft Oil SealAR3Z-7A508-AClutch Slave CylinderAR3Z-7A512-AClutch Slave TubeN808969-S100Clutch Bolt (6 required)F6ZZ-6379-AAFlywheel Bolt (8 required)
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.
OPERATIONDESCRIPTIONTIME100308A2007-2009 Mustang GT500: Replace The Clutch Disc And Plate Assembly; Pilot Bearing, Slave Cylinder And Flywheel. Includes Time To Remove And Install Transmission, Perform The Synchronizer Diagnosis, And Reprogram The PCM (Do Not Use With Any Other Labor Operations)4.2 Hrs.100308B2007-2009 Mustang GT500: Replace The Input Shaft; Synchronizer Assemblies, Clutch Disc And Plate Assembly; Pilot Bearing, Slave Cylinder And Flywheel. Includes Time To Remove And Install Transmission, Perform The Synchronizer Diagnosis, And Reprogram The PCM (Do Not Use With Any Other Labor Operations)
In 1999, I became the editor of 5.0 Mustang magazine, which later fused with Super Ford to become 5.0 Mustang & Super Fords magazine. These days I’m the editor-in-chief.
I currently own a 1988 Mustang LX and a 2008 Shelby GT500, as well as my daily driver, a 2013 Focus ST. Cars I have owned include the aforementioned 1982 Mustang GT, two 1989 5.0 Mustang LX coupes, and a 1998 Mustang Cobra.