04 40th gt

Hey everyone. I have heard some talk from the guys at the dealership that the 03 or 04 model rear ends chatter some. Something to do with the breakdown in the fluid? Just wondering, I noticed I have a lot of chatter in my rear end from time to time when making turns.. Any input would be cool

Raymond

GodAmGT00

Hey Raymond,

It's not just the 03/04 Model, it's just about every single Ford (or subsidiary) w/ the 8.8" rear diff. What causes this, is the Clutch-plates inside the Rear-Diff's center section, are either sticky, or are not slipping enough, causing the clutches to pop and slip erratically..


-Best thing to do is: Remove the rear diff. cover.
-Make sure all of the fluid is drained
-Clean all of the machined surfaces, and the cover, to make sure none of the old RTV is there.
-Reapply a clean, neat bead of RTV around the edges of the cover
-Replace cover
-Empty (1) tube of Friction Modifier (any parts store is sure to have it, or know what you're talking about) into the diff
-Fill Diff w/ 75w90 Gear Oil or better (synth, or not doesn't matter)
-Plug-and-Play

That should solve some of the chattering.

While you've got the rear cover off, inspect the shiny silver gears in the middle (aka. Spider gears) for chipping, or fracturing. Also, make sure there isn't any substantial wear on the Ring gear, or the pinion gear...



JT

FDNYBullitt

There was a bulletin about this a few years back and just adding some friction modifier cured it. If its under warranty just go back to the dealer and complain, good luck.

04 40th gt

Thank you guys for your input. Unfortunately, I can take it to the dealer for warranty work; I bought it used. I will try checking things out in the rear for now and adding new gear oil with the friction modifier. Since it is not that big of a deal right now, I might just wait in til I can get my hands on some better gears. Take care of all the issues at one time.