| LIMITED SLIP AXLE CHATTER, SHUDDER, BINDING SENSATION, OR VIBRATION DURING LOW SPEED TURNING MANEUVERS |
FORD : | 2002-2004 Mustang, Explorer 2003-2004 Expedition 2004 F-150 |
| LINCOLN: | 2003 Navigator |
| MERCURY: | 2002-2004 Mountaineer |
2003-2004 Expedition, 2003 Navigator, 2004 F-150 vehicles equipped with a 9.75″ or 8.8″ limited slip rear axle, and 2002-2004 Explorer 4dr, Mountaineer, and Mustang vehicles equipped with 8.8″ limited slip rear axle, may exhibit a chatter, shudder, a binding sensation, or a vibration during low speed turns.
On 4X4 vehicles, the sensation may appear to be originating from the front axle or the steering gear.
First verify the condition. On 4X4 trucks ensure that the vehicle is in 2WD, to isolate the rear axle.
On all vehicles, turn the wheel fully right (or fully left) and then accelerate the vehicle.
If the condition is verified to be in the rear axle, replace the limited slip clutch pack.
SERVICE PROCEDURE
CAUTION: INSTRUCT THE CUSTOMER NOT TO TOW WITH THE VEHICLE FOR 500 MILES (805 KM) AFTER THIS REPAIR, TO ALLOW THE AXLE TO BREAK-IN PROPERLY.
Order and install the appropriate clutch pack, follow the instructions detailed in the Workshop Manual.
- 6L1Z-4947-A (9.75″ limited slip)
- F5AZ-4947-BA (8.8″ limited slip)
NOTE: INSTALLING A CLUTCH PACK INTO AN INDEPENDENT REAR SUSPENSION (IRS) AXLE IS DIFFERENT FROM INSTALLING A CLUTCH PACK INTO A SOLID-BEAM AXLE. BE SURE TO FOLLOW THE APPROPRIATE WORKSHOP MANUAL PROCEDURE.
INSTALLATION TIPS
- Be sure to install NEW circlips and halfshaft/wheel end nuts on IRS rear axle (not included in the service kit)
- Soak the new clutch packs in Additive Friction Modifier (XL-3) for fifteen (15) minutes prior to installation
- For IRS axles, the half shaft seals need to be replaced. Expedition and Explorer/Mountaineer applications should use seal kit part number 5L1Z-4A109-A. Removal of the half shaft excluder seal 1L2Z-1N013 may be required, if equipped, to facilitate re-assembly
- Refill axles with 4 oz. Additive Friction Modifier (XL-3) and the necessary amount of Rear Axle Lubricant (XY-75W140-QL), regardless of the axle lubricant system originally used in the axle. Fill to capacity recommended in the Workshop Manual
NOTE: AXLE FLUID REQUIREMENTS HAVE BEEN CHANGED. ALL VEHICLES BEING REPAIRED BY THIS TSB MUST HAVE REAR AXLE LUBE XY-75W140-QL INSTALLED, IN PLACE OF XY-75W90-QFEHP. AS PART OF THIS REPAIR, CHECK AND REPLACE IF NECESSARY THE CURRENT XY-75W90-Q”FEHP” METAL TAG, WITH A NEW 75W140 TAG (F3TZ-4121-AA). ADDITIONALLY, REMOVE THE MULTI-COLORED LABEL WHICH IS LOCATED ON THE RIGHT SIDE AXLE TUBE, OR BLOCK OUT ANY/ALL “FEHP” OR “75W90” REFERENCES ON THE LABEL.
| PART NUMBER | PART NAME |
6L1Z-4947-A
Ford Diff Plate Kit
Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API | 9.75″ Axle Clutch Kit |
| F5AZ-4947-BA | 8.8″ Axle Clutch Kit |
| 5L1Z-4A109-A No products found. | Axle Seal |
| XY-75W140-QL
Last update on 2026-06-10 / Affiliate links / Images from Amazon Product Advertising API | Rear Axle Lubricant |
XL-3
Genuine Ford Fluid XL-3 Friction Modifier Additive - 4 oz.
Last update on 2026-06-18 / Affiliate links / Images from Amazon Product Advertising API | Additive Friction Modifier |
W710084-S439
New Genuine Ford Nut - Adjusting Screw W710084S439 / W710084-S439 OEM
Last update on 2026-06-18 / Affiliate links / Images from Amazon Product Advertising API | Nut (Wheel End) |
| 2L1Z-4B422-CA No products found. | Circlips (for 9.75″) |
| 1L2Z-4B422-BA
Last update on 2026-06-18 / Affiliate links / Images from Amazon Product Advertising API | Circlips (for 8.8″) |
| F3TZ-4121-AA | Metal Tag – 75W140 |
- For use on certain limited-slip differentials to reduce chatter and hypoid gear noise levels
- Use according to owner guide recommendations
- Formulated for automotive use
- Added to lubricants to reduce the surface friction of the lubricated parts
- Country of Origin : China
- Package Dimensions: 1.778 L x 10.668 H x 1.778 W (centimeters)
- Fit type: Vehicle Specific
- Package Weight: 0.091 kilograms
- The information below is per-pack only
- For use on certain limited-slip differentials to reduce chatter and hypoid gear noise levels
- Use according to owner guide recommendations
- Formulated for automotive use
- Added to lubricants to reduce the surface friction of the lubricated parts
- Positraction additive
- For use in any clutch-style limited slip
- Compatible with most mineral and synthetic oils
- Positraction Limited Slip Differential Additive
- For use on certain limited-slip differentials to reduce chatter and hypoid gear noise levels
- Use according to owner guide recommendations
- Formulated for automotive use
- Added to lubricants to reduce the surface friction of the lubricated parts
Last update on 2026-06-18 / Affiliate links / Images from Amazon Product Advertising API
This product presentation was made with AAWP plugin.