redden711

I looked over a few of the 5,200 posts regarding 'vibration', but thought I would throw this out there--even though chances are it has been covered. I have a 2008 F150 Lariat that is my toy and it has 7,300 miles on it. About 2,500 miles ago, I had Tom's 4X4 install a 4" lift with Crank 18" wheels on 34" Nitto Terras. There is a slight vibration from the back end only when taking off. I did see a post about a 'modifier'-- but I dont know what that is. I have a Mag Hytec dif cover and the fluid levels are ok. I honestly thought it was normal b/c of the lift, but a buddy told me otherwise. Any ideas on how I can get started resolving this would sure be appreciated---it's driving me up the wall.

bobkyle2

Yep..... Need to change your rear diff fluid and add a bottle of friction modifier .. Its pretty common.. My 08 has done it since 20k miles. And they rebuild the rear end. And it started again withen 10k miles...

I can't make mine completly stop doing it. But i can keep it down to a minimum if i change the fluid like once a year lol... I just ignore it now.

flamehead16

sounds like rear clutch packs. my truck did it forever then stopped. my dads truck started doing it out the blue of late even thought i have had it serviced.

redden711

I'll try this again---
Thanks for yalls advice. I had a diff fluid change today which consisted of 3 quarts of Royal Purple and a bottle of friction modifier. Much better---only day one, but no problems. If it rears its ugly head again, I'll go to step two. Thanks again!

flamehead16

my heavy line tells me with the LSD diffs to drive in a circle each way to work in the fluid.