Jack the rear axle up as described above. That will tell you for sure what you have. Also, if you take the cover off, it's pretty obvious if it's an open differential or limited slip. You can always search online for photos. I took one of mine when I changed the fluid because I didn't recognize the limited slip unit. I thought it might be aftermarket but it's factory.

You can either buy Motorcraft friction modifier or just buy oil with the additive already in it, like Royal Purple.

 

XL-3 Friction Modifier is the OEM goop.

 

The 5 oz tube would be plenty. When I'm done and have extra left I store it in the garage fridge to slow down the silicone from setting up. If it does, you can pull it out of the nozzle easily.

 

I like the lube locker gaskets better than silicone. Haven't had one leak yet and they are reusable. And no silicone to squish out and lodge places.

 

Where did you order your Lube Locker gaskets from??


Swmpbgy1

 

If only there was a web page on the internet where you could go to search for things.... Someone should make one of those. I bet they'd make millions.

For $25 each, I'll stick with RTV. Never had one of those leak either, and as long as you don't overuse the stuff, it's not going to leave pieces of dried RTV anywhere.

 

I'm very happy with my Lube locker reusable gaskets also, not a drop from them.

 

Not to hijack, but I have something similar to this chatter. I hope its something as simple as adding modifier and not bearing related.

 

Can you tell that from the VIN, or do you need the axle code there?

 

I can look it up by the vin but the best way is to jack it up and check. Could be a misbuild or someone before you may have added a limited slip.

 

OK. Do me. I've tried a couple websites, but haven't found one that will tell me something that I don't know.

1FMSU43P35EB13119

 

Ah ha! If you put the VIN in a post here it links you to a decoder. 3.73 LS. Figured it would be, and that's about the limit for a 35" tire.

 

I checked mine, both wheels turn the same way, I did not know it was an LS!!

Trying mine: 1FMNU42P85ED44693

 

Scroll down to the red font, it says "limited slip"

Detailed Vehicle Specification - 1FMSU43P35EB131199:48:48 PM
Description 2005 Excursion
Production Date 2004/10/14
Brand F FORD
Product Type T TRUCK
Vehicle Line VLL1 EXCURSION
Fuel Type D DIESEL
Body Cab Style CAWD 4 DOOR WAGON
Version/Series SEBD 250 SERIES
Plant of Manufacture AAGA1 KENTUCKY TRUCK PLANT BUILD
Engine ENYB 6.0L 325H/550# OHV DI TC V8 DS
Transmission TRBE 5 SPD AUTO 5R110W - HI/TORQUE (IND=A)
Drive Type DR0E 4 WHL L/H PART TIME DRIVE
Axle Ratio EGAJB 3.73 FINAL DRIVE RATIO
Emissions DGAAE 50 STATE EMISSION REQS
Air Conditioning AC0C ATC AIR CONDITIONER
Tire Size D3JYK LT265/75R-16E OWL A-T
Build Information
000BY MEDIUM PEBBLE
5RG00 L1 -D-L -IMOLA LEATHER
A7BAB TAILGATE APPLIQUE-RAISED LTRS
AA5G7 137"/3480MM WHEELBASE
AAAAW LIMITED VERSION
AAEAA LESS SPECIAL PURPOSE VEHICLE
AAFAA LESS FLEET RELATED ITEMS
AAGA1 KENTUCKY TRUCK PLANT BUILD
AAHAB U.S. SALES
AAMAB CONVENIENCE GROUP
AAZLT 9200 LB. GVW
ABEAA LESS SPECIAL VALUE PACKAGES
ABTAA LESS AMBIENT TEMP/SPEED PACK
ACYAB MEMORY PACKAGE
AD6CA 2005 JOB #1 PROGRAM CONTROL
AEAAE ENGLISH LANGUAGE LABEL
AEDAB OWNER HAND BOOK PACK
B2FAD RR QTR VEN WDO-PWR
B2GAE PRIVACY GLASS
B3NAB ELECTRIC REAR WINDOW DEFROSTER
B5VAK OVERHEAD CONSOLE-HIGH SERIES
B5WAG CONSOLE-FLR-FULL UNIQUE
BB7AC ADJUSTBLE ACCL/BRK FOOT PEDALS
BBHAB FRONT THROW IN CARPET FLR MATS
BBIAB REAR THROW IN CARPET FLR MATS
BBKAH FLR CVR-CARPET INS-COMPLETE
BBQAD I/P INSERT - LEVEL 1
BCAAW SNVSR-DUL/LT/ILUM/MIR/HMLK-DRV
BCBAV SUNVSR-DUAL/LT/ILLUM/MIRR
BCMAF DOOR TRIM PANEL-LEVEL 5
BDFAB CARGO COMPARTMENT NET
BDIAM LOAD FLOOR REVERSEABLE MAT
BLBAW RUNNING BOARDS-ILLUM LVL 2
BLDAD UNIQUE BODY COLORED GRILLE
BLYAB ROOF RACK INCLUDING CROSSBARS
BMLAT LOWER PAINTED CLADDING
BSBAF ELECTROCHROMIC INSIDE MIRROR
BSHDJ DU PWR HTD SIGNAL MIRR'S
BY1AB DRIVER HEATED SEAT
BY2AB HEATED PASSENGER SEAT
BYBAD SECOND ROW DUAL CAPTAIN CHAIRS
BYCAB THIRD ROW BENCH SEAT
BYPAC POWER 6-WAY DRIVER SEAT ADJUST
BYQAC POWER 6-WAY PASS SEAT ADJUST
C1CAE TRAILER TOW HEAVY DUTY
C1UAB FRONT TOWING HOOKS
CAAAF EXT DOOR HANDLE-COLOR KEYED
CBAAB POWER DOOR LOCKS
CBFAB DOOR ENTRY REMOTE CNTR UNIT
CFEAC INTERMITTENT RR WND WASH/WIPE
CFFAH SPEED SENSITIVE W'SHLD WIPERS
CJDAA LESS BODY TU-TONE PAINT
CJRAA LESS BODYSIDE ACCENT STRIPE
CLFAC FRONT BUMPER-STEEL-PAINTED-STD
CLMAS REAR BUMPER-STEEL PAINTED
CLVAB FRT LICENSE PLATE BRKT/HOLDER
CPGAB AIR BAG RESTRAINT-DRIVER
CPHAB AIR BAG RESTRAINT-PASS
D2XTU 7.0 X 16" FORGED PREM ALUM WHL
D3JYK LT265/75R-16E OWL A-T
D3MEN SP TIR-LT265/75R16 OWL A/T
D5AAA LESS WHEEL COVERS
DEBAA LESS IMMERSION HEATER
DGAAE 50 STATE EMISSION REQS
DYFBK 5200 LB. FRONT AXLE
DYKAB FRONT STABLIZER BAR
DZLAA LESS REAR STABLIZER BAR
EGAJB 3.73 FINAL DRIVE RATIO
EGJAC LIMITED SLIP REAR AXLE
EJALB 7000 LB(3182 KG) REAR AXLE ASY
FEAAB 4 WHL ANTI-LOCK BRAKES
FMLAC ELECTR TRANS CASE & AUTO HUBS
FMNAB SKID PLATES
FS00D SEAT-CAPTAIN CHAIR-DRV/PASS
GBVAJ DIESEL FUEL CAPABILITY
GRAAC TILT STEERING WHEEL
GTAAJ STEERING WHEEL-DELUXE
GTDAB SPEED CONTROL
GZAAA LESS AUXILIARY HEATER
HDHAB MPH/KPH SPEEDOMETER
HEBAB TRIPMINDER
HLHAB REVERSE PROXIMITY SENSOR*DSN A
HTAAC HEAVY DUTY BATTERY
HUAAD EXTRA HEAVY DUTY ALTERNATOR
IBAMJ AM/FM STRO/CD CHANGER/CLK
IBMAB NAAO RADIO FREQUENCY
IEMAC FAMILY ENTERTAINMENT SYS-VER 1
IGAAB REAR SEAT RADIO CONTROLS
J5XAB COMFORT PACK
JAEAB HOMELINK
JBBAJ JEWELED - HEADLAMPS
JBCAA LESS DAYTIME RUNNING LAMPS
JBKAB FRONT FOG LAMPS
JCGAC DUAL BEAM DOME MAP LIGHT
JEDAC AUTOMATIC HEADLAMP CONTROL OFF
MD00F NO DESCRIPTION AVAILABLE
PNUAA EBONY SOLID C/C
SATAB GENERIC COUNTRY GROUP 1
SBRVT VEHICLE REG CODE LABEL
TAALS YC35 5310 ADA L/F COIL
TACLS YC35 5310 ADA R/F COIL
TAPAA TAPAA
TAQAA LESS B&A CONTROL CODES (9270)
TASAA NO DESCRIPTION AVAILABLE
TATAY TR3 TUTONE LT. PRAIRIE TAN
TDAAW OVERSPEED WARNING DISABLED
WANAB USA
XAENX EXCEPT NORWAY
XAFAB EXC GVMT SERVICE ADMIN
XANAC EXCEPT CANADA
XATAB EXCEPT GUAM
XSAAA EXCEPT BAHRAIN
YC5AB MRKT CB-HTD SEATS/MEM/STG WHL
YCLAB MRKT COMB-HEATED SEAT-DRV/PASS
YCMAA LESS MRKT CB-FRONT SEAT/TRIM
YP3AA LESS TRAILER TOW GROUP PACK
YP4AB CARGO PACKAGE
YZCBH TPO/ORDER CODE 431A
YZTAA LESS MKTG TRIM

 

Scroll down to the red font, it says "non limited slip"

Detailed Vehicle Specification - 1FMNU42P85ED446939:51:58 PM
Description 2005 Excursion
Production Date 2005/07/27
Brand F FORD
Product Type T TRUCK
Vehicle Line VLL1 EXCURSION
Fuel Type D DIESEL
Body Cab Style CAWD 4 DOOR WAGON
Version/Series SEBD 250 SERIES
Plant of Manufacture AAGA1 KENTUCKY TRUCK PLANT BUILD
Engine ENYB 6.0L 325H/550# OHV DI TC V8 DS
Transmission TRBE 5 SPD AUTO 5R110W - HI/TORQUE (IND=A)
Drive Type DR0B 2 WHL L/H REAR DRIVE
Axle Ratio EGAJB 3.73 FINAL DRIVE RATIO
Emissions DGAAE 50 STATE EMISSION REQS
Air Conditioning AC0C ATC AIR CONDITIONER
Tire Size D3JYJ LT265/75R-16E OWL A-S
Build Information
000BY MEDIUM PEBBLE
5RG00 L1 -D-L -IMOLA LEATHER
A7BAB TAILGATE APPLIQUE-RAISED LTRS
AA5G7 137"/3480MM WHEELBASE
AAAAW LIMITED VERSION
AAEAA LESS SPECIAL PURPOSE VEHICLE
AAFAA LESS FLEET RELATED ITEMS
AAGA1 KENTUCKY TRUCK PLANT BUILD
AAHAB U.S. SALES
AAMAB CONVENIENCE GROUP
AAZKY 8900 LB. GVW
ABEAA LESS SPECIAL VALUE PACKAGES
ABTAA LESS AMBIENT TEMP/SPEED PACK
ACYAB MEMORY PACKAGE
AD6CB 2005 JOB #2 PROGRAM CONTROL
AEAAE ENGLISH LANGUAGE LABEL
AEDAB OWNER HAND BOOK PACK
B2FAD RR QTR VEN WDO-PWR
B2GAE PRIVACY GLASS
B3NAB ELECTRIC REAR WINDOW DEFROSTER
B5VAK OVERHEAD CONSOLE-HIGH SERIES
B5WAG CONSOLE-FLR-FULL UNIQUE
BB7AC ADJUSTBLE ACCL/BRK FOOT PEDALS
BBHAB FRONT THROW IN CARPET FLR MATS
BBIAB REAR THROW IN CARPET FLR MATS
BBKAH FLR CVR-CARPET INS-COMPLETE
BBQAD I/P INSERT - LEVEL 1
BCAAW SNVSR-DUL/LT/ILUM/MIR/HMLK-DRV
BCBAV SUNVSR-DUAL/LT/ILLUM/MIRR
BCMAF DOOR TRIM PANEL-LEVEL 5
BDFAB CARGO COMPARTMENT NET
BDIAM LOAD FLOOR REVERSEABLE MAT
BLBAC RUNNING BOARDS-LIGHTED
BLDAD UNIQUE BODY COLORED GRILLE
BLYAB ROOF RACK INCLUDING CROSSBARS
BMLAT LOWER PAINTED CLADDING
BSBAF ELECTROCHROMIC INSIDE MIRROR
BSHBK DU TLSCP TTW PWR HTD DS RLTS
BY1AB DRIVER HEATED SEAT
BY2AB HEATED PASSENGER SEAT
BYBAN SEC ROW 60/40 (3 P)-EASY ENTRY
BYCAB THIRD ROW BENCH SEAT
BYPAC POWER 6-WAY DRIVER SEAT ADJUST
BYQAC POWER 6-WAY PASS SEAT ADJUST
C1CAE TRAILER TOW HEAVY DUTY
C1UAB FRONT TOWING HOOKS
CAAAF EXT DOOR HANDLE-COLOR KEYED
CBAAB POWER DOOR LOCKS
CBFAB DOOR ENTRY REMOTE CNTR UNIT
CFEAC INTERMITTENT RR WND WASH/WIPE
CFFAH SPEED SENSITIVE W'SHLD WIPERS
CJDAA LESS BODY TU-TONE PAINT
CJRAA LESS BODYSIDE ACCENT STRIPE
CLFAC FRONT BUMPER-STEEL-PAINTED-STD
CLMAS REAR BUMPER-STEEL PAINTED
CLVAB FRT LICENSE PLATE BRKT/HOLDER
CPGAB AIR BAG RESTRAINT-DRIVER
CPHAB AIR BAG RESTRAINT-PASS
D2XTU 7.0 X 16" FORGED PREM ALUM WHL
D3JYJ LT265/75R-16E OWL A-S
D3MEM SP TIR-LT265/75R16 OWL A/S
D5AAA LESS WHEEL COVERS
DEBAA LESS IMMERSION HEATER
DGAAE 50 STATE EMISSION REQS
DYFBE 4700 LB. FRONT AXLE
DYKAB FRONT STABLIZER BAR
DZLAA LESS REAR STABLIZER BAR
EGAJB 3.73 FINAL DRIVE RATIO
EGJAB NON-LIMITED SLIP REAR AXLE
EJALB 7000 LB(3182 KG) REAR AXLE ASY
FEAAB 4 WHL ANTI-LOCK BRAKES
FF1AB NORMAL FUEL FILL
FMLAA LESS TRANSFER CASE
FMNAA LESS SKID PLATES
FS00D SEAT-CAPTAIN CHAIR-DRV/PASS
GBVAJ DIESEL FUEL CAPABILITY
GRAAC TILT STEERING WHEEL
GTAAJ STEERING WHEEL-DELUXE
GTDAB SPEED CONTROL
GZAAA LESS AUXILIARY HEATER
HDHAB MPH/KPH SPEEDOMETER
HEBAB TRIPMINDER
HLHAB REVERSE PROXIMITY SENSOR*DSN A
HTAAC HEAVY DUTY BATTERY
HUAAD EXTRA HEAVY DUTY ALTERNATOR
IBAMJ AM/FM STRO/CD CHANGER/CLK
IBMAB NAAO RADIO FREQUENCY
IEMAC FAMILY ENTERTAINMENT SYS-VER 1
IGAAB REAR SEAT RADIO CONTROLS
J5XAB COMFORT PACK
JAEAB HOMELINK
JBBAJ JEWELED - HEADLAMPS
JBCAA LESS DAYTIME RUNNING LAMPS
JBKAB FRONT FOG LAMPS
JCGAC DUAL BEAM DOME MAP LIGHT
JEDAC AUTOMATIC HEADLAMP CONTROL OFF
MD00F NO DESCRIPTION AVAILABLE
PN3B1 PUEBLO GOLD
SATAB GENERIC COUNTRY GROUP 1
SBRVT VEHICLE REG CODE LABEL
TAALK YC35-5310 -SA L/F COIL (TCP)
TACLK YC35-5310 -SA R/F COIL (AS )
TAPAA TAPAA
TAQAA LESS B&A CONTROL CODES (9270)
TASAA NO DESCRIPTION AVAILABLE
TDAAW OVERSPEED WARNING DISABLED
WANAB USA
XAENX EXCEPT NORWAY
XAFAB EXC GVMT SERVICE ADMIN
XANAC EXCEPT CANADA
XATAB EXCEPT GUAM
XSAAA EXCEPT BAHRAIN
YBCAD MRKTG BODY CODE-U42
YC5AB MRKT CB-HTD SEATS/MEM/STG WHL
YCLAB MRKT COMB-HEATED SEAT-DRV/PASS
YCMA5 SPORT BUCKET/LEATHER
YP3AA LESS TRAILER TOW GROUP PACK
YP4AB CARGO PACKAGE
YP8AA LESS TRAVEL PACKAGE
YZCAT TPO/ORDER CODE 351A
YZTAA LESS MKTG TRIM