SO I am starting a new thread and hopefully the last for this problem I am having..

Seems when I put my truck in 4x4 High I get a slight vibration throughout the truck...And sometimes out of nowhere while driving down the road in 2wd a vibration will slowly start and increase in intensity until I slow down. Then it goes away like it never happened.

Am I going F&%in crazy here or whats the deal? The truck is an 04 FX4 with a 6" lift and 35's. All the rest of the time it drives completely normal..Somebody help me out here!

 

the front driveshaft will do that when lifted if not corrected

 

yep, look for a longer front driveshaft.

rancho and skyjacker should make one. search their sites.

 

I have the same problem after installing a Procomp 6" lift and 35"s on my 05 screw. What exactly is causing this? Is a longer front driveshaft the only solution? And RI04F150 what kind of lift and tires you put on?

 

after the lift is put on, the manufacturers recommend that you have the front drive shaft balanced. this is because you have to grind out the set key in order to re-clock the yokes. although, it isnt always needed.... i did mine without balancing it, and i dont get any vibrations with it. now, this "could" explain some of your problems, but it would have nothing to do with a vibration in 2wd, since the shaft does not spin in 2wd.

the other day i had to fix a 4wd vibration i was having. mine turned out to be that i had 2 loose bolts and 2 missing bolts where the front drive shaft mounts to the transfer case. ive had my lift for a little over a year, so i guess its time to re torque everything. you could have a similiar issue going on, but not necessarily with the front drive shaft.

 

so where can you get your drive shaft re-balanced?

The vibration I get in 2wd has only happened twice and it felt like it was coming from the rear end. both times I pulled over, looked under the truck and then got back on the road with no vibration after stopping and taking a look. Is it possible I could have hit a bump that threw something off causing the vibration? The only reason I ask is because after I stopped both times it went away..???

 

I am running a fabtech 6" performance lift and 325/65/18 nitto terra grapplers..

 

Also check your emergency brakes when this happens. If you are getting a hot smell from them, that is the cause. My 04 did the same thing until the dealer backed off a little on the e-brakes. For whatever reason, it would rub, heat up the disks causing the vibration.

 

Ditto on the emergency brake

 

that sounds like it would make sense..I spoke to someone at Fabtech and they said that it is very common to get vibration in 4x4 high with the performance lift on an 04...usually at higher speeds but not uncommon at low speeds..The answer is the aftermarket driveshaft ($900.00)..for that price I think I can deal with a little vibration! I will look into the E-brake issue and see what happens. Thanks for the help.