Getting right to the point, my stock 04 crewcab f150 has a slight chatter to it when I take off. It is especially noticable when I am turning from a stop. The feeling is like I have knobby tires and for a second or two I feel the tires trying to catch traction.

That is how it feels but i have the stock wheels/tires and the truck is a 2wd? Now when I had my 22's on the truck it really felt bad and the wheels actually made the tranny feel like it was slipping. I removed them and the trans part seems fine now, but I still cannot figure out what is up with the rear chattering a bit. Has this happened to anyone else? Any advice as to fixing it?

I was wondering if the GF lowering shackles/shims might help it, cuz maybe it is a pinion thing! Please HELP me.

Thanks
Brad

 

Coming from the front or the rear?

 

im gonna guess rear.

describe chattering. do the tires feel like they are slipping? had the limited slip looked at?

 

ahhh.

Change the diff fluid, and add BG differental additive. My truck did the same thing about 6 months ago. Changed the fluid and it went away (not immediatly, but it did.)

 

Yes the rear end is the problem. And yes it feels like it is slipping a wee bit but why it does it more when I am turning the front wheels is what gets me.
I had the rear and trans looked at a good while ago, but they said they could not see anything. Funny I can everytime I drive it and of course I have no warranty remaining... That is why I asked about the GF kit and shims, because maybe the pinion is off just enough to cause this feeling!

I am anxious to hear anymore thoughts.

 

thanks FX41, how much fluid did it take?

 

If you have the LS rear, then it is trying not to slip when you turn, and the wheels are wanting to go different speeds. It's normal.

 

Oh, it was like 6 months ago, I think it took about 2.5 quarts + the additive.

 

It's the clutch packs in the rear diff.. Very common problem, I did a ton of them. What you're describing is exactly how it reads in the TSB for it. There's updated clutch packs that are supposed to go in under the TSB but, you could maybe try changing out the fluid and adding a bit more friction modifier to it.

 

Yep the same thing happend to my 2001 Exploder.

It needed the friction moddifier./;

 

Great AZ, thanks for the input. What/how much friction modifier should I add? What is the TSB? I will see if I can take care of this. I really appreciate the info and how much would replacing the clutch packs cost me?

 

TSB
06-4-4 LIMITED SLIP AXLE CHATTER, SHUDDER, BINDING SENSATION, OR VIBRATION DURING LOW SPEED TURNING MANEUVERS

Publication Date: February 13, 2006

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.

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 9.75" Axle Clutch Kit
F5AZ-4947-BA 8.8" Axle Clutch Kit

Here's a tsb on the matter. It's been a while since I've been at the dealership so there might be an update, but that would be just some part #'s. If I remember correctly, it was like 3 hrs. labor. You could call the dealer and ask a service advisor. Don't let him tell you to just bring it in and they'll take a look, just specifically ask what it would cost to replace the clutch packs. If you're just gonna drain and refill the diff., it takes one whole bottle of friction modifier. You could maybe try adding a little more, say a quarter of a bottle. Don't get that stuff on your clothes, it reeeeeeeeks!

 

Just to update anyone interested or whoever else might run into this issue. I recently drained the rear differential and added LUCAS rear end fluid along with a friction modifier/additive and it seems to have done the job. So much cheaper than dealing with the dealer. Thanks for all the help and suggestions guys.

Brad

 

i have the same problem as you described what type of oil and additive did you use- thanks mike

 

Mine has just started doing this. Oh what joy.

So if I were to change diff fluid myself, what would I need to get?