Hello,

I have a 2007 F150 4x4 and have started to notice a slight vibration in the morning when I make a turn. I am thinking it could be the rear diff. After I make that initial turn in the morning the problem does not occur again. I had the diff fluid changed at 28,000 miles. I am now at 29,000. I am wondering if I should change the rear diff fluid again. I plan on driving this truck until it turns to dust so I want to be sure to take good care of it. Any suggestions?

I was just going to put in some friction modifier but I am afraid that they actually did put some in already and I would wind up with too much. Any help would be appreciated.

Thanks in advance,
Wayne

 

Spend the money and get a real LS, the factory units are junk. Try to get one like the detroit truetrac, they do not have clutches so they don't need friction modifier.

 

If you have the 5.4 engine, then you have the 9.75 axle.

http://www.drivetrainspecialists.com...duct-5441.html

If you have the 4.6, then your axle is an 8.8 with 31 splines.

http://www.drivetrainspecialists.com...duct-5411.html

 

im not fimiliar with that true trac whats the difference in the true trac and the locker? is the true trac a limited slip?

 

Just add another bottle of friction modifier. Buy it from Ford.

 

Thanks Roadie. I bought some and added it. I will find out tomorrow morning if it worked.

05RedFX4 - I will be going your route if the FM doesn't do the trick.

It pisses me off that I am even having a problem . I baby this truck.

Thanks again for the help Gentlemen.

Wayne

 

Warranty?

 

While it's under warranty, let Ford correct it on their dime, if you go & install anything to that rear end, you will be screwed in terms of your warranty!!!