That was just for the rear. My truck is 2wd.

 

ahh ok thanks

 

problem solved see first post

 

Only the rear diff needs modifier - and are they going to change the fluid while they are at it?

 

yes they did. the vibration is all but gone already.

 

Yea, it only takes about 75 miles,- if that.

 

You guys are funny, the rear was chattering because the clutch packs are worn out. Adding the friction modifier to dying clutch packs just makes them wear out faster. The reason they're not making noise anymore is because they're not working. Sounds like a waste of $ doing a diff service. Not sure if it was stated but the LSD rears take 75w140 ---professional ford tech opinion

 

No worries dennis03fx4, you did just as directed by the manufacturers TSB/ customer interest.

___________________

Drexelsteve - Friction modifier is Ford spec in that pig = 4 oz's.

Yes, pay attention, lube was mentioned - SAE 75W-140 High Performance Rear Axle Lubricant.

Or-

Motorcraft Synthetic Rear Axle Lubricant part number F1TZ-19580-B.
Meeting Ford specification WSL-M2C192-A.

Modifier -

Ford Friction Modifier part number C8AZ-19B546-A.
Meeting Ford specification EST-M2C118-A.

Capacity -

Rear Axle 5.5 Pints.

Friction Modifier 4 oz.

Rear axle fill no higher than 1/4 - 9/16 inch below bottom of fill hole.

_______________________________________

A "chattering" noise from the rear axle may be heard when turning or cornering. This is due to either the differentials containing clutch packs have been gauged too tightly or may be due to modifier/fluid breakdown in higher mileage vehicles.

_____________________


Now get your *** back to class and leave this guy alone

 

Tsb number? Saw no record of this bandaid pertaining to 03's... And is this before or after they redesigned the friction discs in the clutch packs so that they wouldn't wear out so easily? If you'd like part numbers I could dig them up at work lol.