I know I have to replace the gear oil after the first 500 miles,but could I get by with keeping the additive out until I replace the oil ?wont it just chatter a bit without it for the first 500 miles,keeping in mind that I will be driving very easy.
Replace the rear diff oil after 500 miles? Really?
Question, does a new car get a rear diff oil replacement after 500 miles? Most cars these days get Synthetic oil that's good for 100k miles. I personally think that's too long. But even at 50k miles, thats still a long time.
Note, Ford does recommend no towing for the first 500 miles. For the Mustang owner, I would assume that means "easy driving".
There is a Ford TSB that calls for use of a different weight oil after rebuilding a rear end. Previously Ford recommended 75W90 for the 2002+ MY. The recommended fluid is 75W140 to reduce LSD clutch chatter. I personally followed Ford new recommendation when I rebuilt the rear-end in my 2000 GT.
>>> TSB 06-4-4
03/06/06
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
This article supersedes TSB 06-02-16 to update the Service Procedure.
ISSUE
Some 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.
ACTION
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.
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 SL1Z-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 XY75W90-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.