2001 F250 Crew Cab, PowerStroke 56K miles

Should I be able to move the driveshaft within the center carrier bearing? In other words, I lay under the truck grab the driveshaft close to the center carrier and move the driveshaft up and down. I have considerable movement

Owned this truck since new, never had vibrations until I decided to get a leveling kit from Fabtech and get 305/70/16 Goodyear AT/S. Put on leveling kit and drove to get tires (no noticable vibrations on the way there)

After tires installed, noticed vibration started around 55mph and got worse to 70mph. But vibration was inconsistent. seemed like when I hit some grooved pavement, would clear up , then come back. Also seemed better on colder mornings. Got front tires re-balanced, this didn't help.

Next thing I did was lengthened my track bar because I didn't like how the Fabtech put the suspension in a bind. most other venders provide some sort of track bar relocation adjustment. I also alligned the front end. This improved things somewhat, but I still noticed vibration.

Next I added some blocks to the rear because Fabtech's leveling kit actually made the front sit 1.5 inches higher than the back. Now I feel the shudder at take off that is talked about on other discussion threads. I think shimming the carrier bearing down should help this.

I like the way the truck sits now, but wonder if I've made a big mistake by installing this lift and tires. PLease tell me if the driveshaft center carrier is suppose to be solid feeling.

Thanks, Roy

 

Welcome to FTE!

I think you do need to install a drop-down bracket on your carrier bearing. This could eliminate the problem - if you know for sure your tires are not out-of-round.

As I have stated before: You can balance a football, but it still wobbles when rolled.

The carrier bearing should have some play, but not much.

 

You need either a good shim kit or a one-piece driveshaft. The center carrier bearing sits or floats in a rubber insulator, but it should be fairly stiff to move around. Mine moves a little bit in all directions with a good amount of push. After my lift kit was installed, I bought the shim kit made by SuperLift or ProComp, I can't remember. I ended up droping the carrier bearing 1 3/4" to completely eliminate the vibration. There needs to be no more than 3 degrees of orientation difference between all 3 u-joints. Basically I lowered the carrier until the two driveshafts were almost in a straight line. Loctite and a good torque wrench is all you need for this, everything else is in the kit. The kit is about $35. If that doesn't work, then you can have a custom 1-piece driveshaft made. It's only about $150 and will fix your problem for sure.