SHUDDER ON ACCEL - POSSIBLE WRONG TRANS CROSSMEMBER ASSEMBLY INSTALLED (EXCLUDES GT 500)
Publication Date: October 31, 2008
2005-2009 Mustang, Mustang
Some 2005-2009 Mustangs vehicles (Excludes GT 500), equipped with either a 4.0L or 4.6L engine, may exhibit a heavy driveline shudder on acceleration from a stop or between 3-15 MPH (5-24 Km/h). On 4.0L engines there may also be an above average engine presence. The wrong transmission crossmember assembly may have been installed from the factory. Similar complaints may also occur if the transmission crossmember and transmission support insulator were improperly reassembled after transmission removal.
Follow the Service Procedure steps to correct the condition.
Inspect the transmission crossmember assembly orientation. (Figure 1)
Figure 1 - Article 08-23-4
4.6L V8 vehicles - Transmission crossmember hump should extend upward. Transmission support insulator (trans mount) should have a white or yellow paint dot.
4.0L V6 vehicles - Transmission crossmember hump should extend downward. Transmission support insulator (trans mount) should have a blue paint dot.
EXHAUST MOUNTS AND ISOLATORS, SHOWN IN FIGURE 1, WERE PRODUCTION ASSEMBLY AIDS AND ARE NOT REQUIRED. THEY WERE DELETED ON VEHICLES BUILT AFTER 12/03/2007 AND MAY HAVE ALREADY BEEN REMOVED PER TSB 08-3-4.
If the vehicle is found to have the wrong transmission crossmember, then remove the transmission crossmember per Workshop Manual (WSM), Section 502-00.
Remove the transmission support insulator (transmission mount) from the transmission crossmember.
If present, remove and discard exhaust mounts and isolators from the transmission crossmember. The transmission crossmember exhaust mounts and isolators are a production assembly aid and are not required. Do not cut off the hanger rod from the exhaust system.
Orient the original transmission crossmember to match engine. (Figure 1)
Install new engine-specific transmission support insulator (transmission mount) onto transmission crossmember. (Figure 1)
Torque transmission support insulator (trans mount) nuts to 52 lb-ft (70 N-m).
Install the transmission crossmember per WSM, Section 502-00.
DO NOT REINSTALL TRANSMISSION CROSSMEMBER EXHAUST MOUNTS AND INSULATORS.
Bend exhaust hanger rods to a horizontal position to create approximately 2" (50 mm) clearance to the transmission crossmember. (Figures 2-3)
Figure 2 - Article 08-23-4
Figure 3 - Article 08-23-4
Verify the exhaust system is properly aligned by measuring the distance between the exhaust pipe and floor pan (behind the catalytic converter). The distance should be 2" ± 0.5" (50 mm ± 13 mm). If not, then re-align exhaust system using procedure in online WSM Section 309-00.
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.
2005-2009 Mustang 4.0L: Replace The Transmission Crossmember, Includes Time To Align Exhaust If Necessary (Do Not Use With 5025A, 5200A)
2005-2009 Mustang 4.6L: Replace The Transmission Crossmember, Includes Time To Align Exhaust If Necessary (Do Not Use With 5025A, 5200A)