Needing some help. I'm stumped.

A little about my truck. E99 F-350 crew cab long bed dually 4x4 223K miles. 4.10 gears with LS in rear.

I bought the truck June 2016. I ended up wrecking the truck on the test drive. Thought it was a 4 way stop and pulled out in front of a lady and she ran into the passenger side tire. Only damage that was on the truck was a busted tire, and the fender smashed in. Some how missed the door and the bumper.

I replaced all the front end: u-joints, ball joints, steering linkage, brakes, rotors, calipers, and all the u-joints in both of the drive shafts, also changed the fluid in both axles.

I have started to notice a slight "vibration" "shimmy" while driving down the road. Mainly while in a curve or changing lanes; applying pressure to the steering wheel one or the other. Tires have been balanced, and rotated several different times now with no help at all.

While backing up, I can feel something "popping" "clunking" especially while turning. Like backing out of a parking space.

Insert troubleshooting:

Jack truck up and put on jack stands.

-Pull and shake all tires. --No movement

-Put in drive and watch all the rear end. --Nothing shaking or out of sync.

-Put truck in 4wd, hard to engage, watch front end. --Nothing shaking or out of sync.

-Turn tires to full lock. --Drive line starts clanking and shaking and rear tires acting funny.

-Turn tires straight. --Problem goes away.

-Put truck back in 2wd. --No problems when turning wheel lock to lock.

-Drive to empty parking lot. --Mainly feel problem while backing up, really have to feel for it. Most people call me insane.

-Lock the front axle. --No difference.

-Put in 4wd. Drive straight --No difference.

-In 4wd while turning. --Truck wants to act like it is fully locked in the rear and will bind up and slip a tire. You really have to give it some fuel to make it even try to move, and its almost like the truck wants to fold in half on itself. Cant keep the steering wheel in one spot as it keeps "jumping" on me.

-Put in 2wd. --Acts the same way until the truck fully comes out of 4wd then smooths back out to where you have to really feel for it. 4wd light stays on forever, before going off later in life.

-Put in 4low. --Gears grind and will not engage.


Would this indicate that the transfer case is messing up on me? Why would the rear axle feel like it is locked when in 4wd?

How does one upload a video on here? Maybe that would help some to understand the problem?

 

I would try to isolate the front end from the rear end by dropping the real drive shaft and see what changes....10 bolts total and 10 mins.

If nothing, replace it and then drop the front drive shaft and see what happens. Did you replace all of the u-joints in the double cardan?

Are you completely stopped when you shift to 4Lo

 

Yes I replaced 3 u-joints in front and 3 in rear. I guess I might add that I was having these problems before the u-joints in the drive lines. All the front end work was done before I could start driving the truck.

I had considered dropping the rear drive shaft, but it was already getting late that night and didn't have a chance too. I guess removing the front would elimate anything from the front end putting a bind on the transfer case when in 2wd, even though nothing should be turning with the hubs unlocked.

4low is nothing but grinding. Put in neutral, shift to 4low, shift to drive, loud grinding, quickly shift to neutral and listen to it grind until it stops spinning. try hard as you can to go back into 4hi.