Hi - Some time ago ,I posted that I had shudder in the drivetrain when I first started and when I turned. I finally determined that the clutch packs in the limited slip rear axle were causing the problem. I tried the Ford friction modifier along with changing to 140W lubricant ,but it did not make a difference. Then I saw a post from a mechanic member who recommended RedLine lubricant 140w with the friction modifer and it worked!!! When I first changed ,the difference was minimal ,but within 30 days the shudder was gone!! Even Redline's website mentions that this type is used to correct rear axle problems in late model Ford trucks. Thanks to the member who posted that tip!!

 

Brandi

Thanks for the info - my 05 Supercab seems to have started with the shudder. Ford claimed it is caused by the "drive by wire" feature and it is normal. That may be but I will try your "fix"

Kenny

 

Good post, might change to Redline next service thats done.

 

[yawns] Old news. High quality gear oil with friction modifier is all it takes in 90% of the cases.

-Joe