I have a 04 F150 that has a serious howl between speeds of 30 and 80 mph, it goes away if you let up on the accelerator. I pulled the rear end pan off and replaced the fluid, all the gears looked good. Drive shaft seems tight, I pulled the drive shaft off and test drove a short distance with the front drive shaft and no howl. Anyone experience this?

 

Well, it sounds like you have a pinion gear backlash setting issue or irregular gear wear.

 

I agree, had the same issue in an 1999 suburban i had I brought it in they replaced everything parts labor out the door was $690.

 

Rear end gear shims are not lined up the right way and have worn out. The rear end is making the noise, but this is also because of a unbalanced drive shaft. They are all linked. If its under warranty go get a new drive shaft and have new rear end gears and shims.

 

Is that an indicator that it is the rear end when it is making noise only on when you are on gas and accelerating? Does it make noise when decelerating?

 

Sometimes, it will get so bad that you need ear plugs to drive at 60

 

My 97 did the same thing.The carrier bearings and pinion bearings were wore out!

 

pinion bearing would be my guess if the gears look right. Did you mark them to see where they were making contact to ensure proper aligment? If you did I'd say it's the pinion bearing and the seal will be next. I'd get a new bearing, seal and crush washer and replace them.

 

TSB 05-23-3

ISSUE:

Some vehicles may exhibit an axle whine or hum during acceleration, deceleration and/or cruise.
ACTION:

An axle repair kit has been developed which incorporates most parts required for a comprehensive axle repair. The kit should be used instead of installing a complete axle assembly to repair an axle whine/hum. Replace Ring and Pinion with Axle Kit and Components.
<table border="0"><tbody><tr><td width="80">NOTE:</td><td>REFER TO THE "DIFFERENTIAL RING AND PINION" IN-VEHICLE REPAIR PROCEDURE IN THE ONLINE WORKSHOP MANUAL SECTION 205-00, FOR THE LATEST AXLE DIAGNOSIS AND REPAIR PROCEDURES.</td></tr></tbody></table>

<table border="0"><tbody><tr><td width="80">NOTE:</td><td>FOR 1999 AND PRIOR MODEL YEAR VEHICLES, USE THE 2000 MODEL YEAR WORKSHOP MANUAL.</td></tr></tbody></table>

<table border="0"><tbody><tr><td width="80">NOTE:</td><td>WHEN SERVICING THE REAR AXLE ON ANY 2002-2004 F-150, EXPEDITION, NAVIGATOR, EXPLORER OR MOUNTAINEER BUILT BEFORE 3/30/2004, IF FLUID REPLACEMENT IS REQUIRED, REPLACE THE ORIGINAL FUEL EFFICIENT HIGH PERFORMANCE (FEHP) SAE 75W-90 REAR AXLE LUBRICANT WITH SAE 75W-140 HIGH PERFORMANCE SYNTHETIC REAR AXLE LUBRICANT. WHEN THE FLUID TYPE IS CHANGED, REPLACE THE CURRENT "FEHP" METAL TAG WITH A NEW "75W-140" TAG (F3TZ-4121-AA). IN ADDITION, REMOVE OR BLOCK-OUT THE FEHP REFERENCE ON THE MULTI-COLORED LABEL LOCATED ON THE RIGHT SIDE AXLE TUBE. IF THE AXLE IS A LIMITED-SLIP MODEL, USE XL3 ADDITIVE FRICTION MODIFIER IN THE QUANTITY RECOMMENDED BY THE WORKSHOP MANUAL.</td></tr></tbody></table>

KIT ORDERING: REFER TO THE VEHICLE AXLE TAG FOR AXLE RATIO IDENTIFICATION

• 5L3Z-4209-A = (8.8-Inch Ring Gear/3.31 ratio) (1997-2005 F-150)
• 5L3Z-4209-B = (8.8-Inch Ring Gear/3.55 ratio) (1997-2005 F-150, 2002-2005 Explorer/Mountaineer/Aviator)
• 5L3Z-4209-C = (8.8-Inch Ring Gear/3.73 ratio) (1997-2005 F-150, 2002-2005 Explorer/Mountaineer/Aviator, 2003-2004 Expedition/Navigator)
• 5L3Z-4209-D = (9.75-Inch Ring Gear/3.31 ratio) (1997-2005 F-150, 2005 Expedition/Navigator, 1997-2002 Expedition/Navigator)
• 5L3Z-4209-E = (9.75-Inch Ring Gear/3.55 ratio) (1997-2005 F-150, 1997-2002 Expedition/Navigator)
• 5L3Z-4209-F = (9.75-Inch Ring Gear/3.73 ratio) (1997-2005 F-150, 1997-2005 Expedition/Navigator)

<table border="0"><tbody><tr><td width="80">NOTE:</td><td>9.75 REAR AXLE HOUSINGS WERE REDESIGNED IN MID-1999, INCREASING FRONT PINION BEARING SIZE. REPLACING RING & PINIONS IN AN OLD-STYLE AXLE ASSEMBLY WILL REQUIRE INSTALLATION OF SPACER P/N YL3Z-4662-CA. SPACER IS TO BE INSTALLED BETWEEN INNER PINION BEARING AND COLLAPSIBLE SPACER. </td></tr></tbody></table>

THE AXLE SERVICE KITS INCLUDE THE FOLLOWING COMPONENTS:

• 4630 - Head Bearing
• 4628 - Head Bearing Cup
• 4676 - Pinion Seal
• 386989-S2 - Washer (Slinger)
• 4621 - Tail Bearing
• 4616 - Tail Bearing Cup
• 4222 - Differential Bearing Cups
• 4221 - Differential Bearings
• 4209 - Gear Set (includes pinion shims, pinion nut and crush spacer)
• 4209 - Instruction Sheet

<table border="0"><tbody><tr><td width="80">NOTE:</td><td>THE KIT DOES NOT INCLUDE THE FOLLOWING ITEMS. SOME OR ALL OF THESE ITEMS WILL BE REQUIRED TO COMPLETE THE AXLE SERVICE, DEPENDING ON AXLE APPLICATION/STYLE.</td></tr></tbody></table>

ORDER AS NEEDED:


<table border="0"><tbody><tr><td width="80">NOTE:</td><td>REUSE OF RING GEAR BOLTS, CARRIER BEARING CAP BOLTS AND DIFFERENTIAL SLAVE PIN RETAINING BOLT REQUIRES CLEANING OF THREADS AND INSTALLATION OF TA-27 STUD AND BEARING MOUNT RETAINING COMPOUND & SEALANT.</td></tr></tbody></table>

• YL3Z-4662-CA - Pinion Bearing Spacer for 1997-1998 9.75 axles
• XG-14 - Gear Marking Compound
• 4067 - Differential Shims 0.241" to 0.307"
• SAE XY-75W140-QL - High Performance Synthetic Rear Axle Lubricant
• XL-3 - Additive Friction Modifier (Limited Slip Axles Only)
• 205-506 - Seal Protectors (Rotunda Tool)
• W710084-S439 - Wheel End Nuts
• 390266-S100 - Differential Slave Pin Bolt (9.75" axles)
• 387426-S100 - Differential Slave Pin Bolt (8.8" axles)
• 4B422 - Axle Circlips
• ZC-21 - Metal Surface Cleaner
• TA-29 - Ultra Silicone Sealant
• TA-27 - Stud and Bearing Mount Retaining Compound and Sealer
• F3TZ-4121-AA - Fluid Tag (REQUIRED IF FLUID TYPE IS CHANGED FROM FEHP DURING REPAIR)

WARRANTY STATUS:

Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
<table border="1" cellpadding="3" cellspacing="0"> <tbody><tr> <th align="center">OPERATION</th> <th align="center">DESCRIPTION</th> <th align="center">TIME</th></tr> <tr> <td align="left">052303A</td><td align="left">1997-2002 Expedition, 1998-2002 Navigator, 1997-2004 F-150 Heritage, 2004-2005 F-150: Rear Axle Noise Repair (Includes Time For Road Test To Verify Concern (Beam Axle)) (Do Not Use With 4205A Or 4205A4)</td><td align="left">4.7 Hrs.</td> </tr><tr> <td align="left">052303A</td><td align="left">2003-2005 Expedition: Rear Axle Noise Repair (Includes Time For Road Test To Verify Concern (Irs Axle)) (Do Not Use With 4010D Or 4010D4)</td><td align="left">5.8 Hrs.</td> </tr><tr> <td align="left">052303A</td><td align="left">2003-2005 Expedition/Navigator With Air Suspension: Rear Axle Noise Repair (Includes Time For Road Test To Verify Concern (Irs Axle)) (Do Not Use With 4010D Or 4010D4)</td><td align="left">5.9 Hrs.</td> </tr><tr> <td align="left">052303A</td><td align="left">2002-2005 Explorer/Mountaineer, 2003-2005 Aviator: Rear Axle Noise Repair (Includes Time For Road Test To Verify Concern (Irs Axle)) (Do Not Use With 4010D Or 4010D4)</td><td align="left">6.6 Hrs.</td> </tr></tbody></table> DEALER CODING

<table border="1" cellpadding="3" cellspacing="0"><tbody><tr> <th align="center">BASIC PART NO.</th> <th align="center">CONDITION CODE</th></tr> <tr><td align="center">4209</td> <td align="center">14</td></tr></tbody></table>