Hi I have a 1999 f250 4x4 superduty that I got a few months ago and I have a bad vibration coming from somewhere in my front end. I can get it to stop if I swich it to 4wd. I have tried replacing the hub assemblies but it still does it. I was wondering if anybody has had anything like this happen to there truck

 

What speeds is the vibration worse at? Does it happen when accelerating or when maintaining speed (feathering the pedal)?

 

It's starts when I hit a bump usually. It is about the same whether I'm accelerating or slowing down and stops about 5-15mph. I was thinking maybe the actuator is getting bad

 

Describe the vibration. Where do you feel it? Steering wheel, seat, pedals, radio *****? Does it change in pitch or amplitude with speed? Is it more of a buzz or a wobble?

 

had the same problem(death wobble) with my 2010 I put a new drag link in and it solved the problem

 

Drag link is a good point. Also, how are your axle shaft joints? Ball joints?

 

It doesn't effect my steering at all I can feel it in the floor board I haven't check the axle shaft u joints.

 

You can feel it in the floor... it's your front drive shaft U-Joints. When you put it in 4x4 it puts stress on them and they don't wobble...as much.

 

Thank you I'll try replacing the joints

 

Hub assembly needle bearings that ride on the axle shaft when you put it it 4x4 the axle shaft spins also so the noise stops

 

I will agree on that, but first let me ask the OP, do you HEAR any noise (WINDOWS DOWN?).

Listen for a sound that sounds like birds chirping or a clicking sound.

Drive you truck at low speed listen do it in/out of 4wd. My exp is the vibration comes after the birds chirp, shortly after that your u joint goes to u joint heaven...

 

I can greese the u joint and it stops for a couple weeks. But it doesn't make any chirping noise.

 

haha we had a 98 f250 light duty that ford morphed together from multiple years and 2wd - 4x4 parts.

When you'd hit a bump, the entire truck would shake and chatter like you had 2 flat tires up front.

We rebuild the front end and it still did it. Pitman arm turned out to be the cause of it.

 

The chirping or ticking sound is the sound of dry bearings and the cap rotating


Note the bright area on the cap. This is the cap rotating in the trunnion. Failure is just a few miles away. You will often hear a chirping or ticking sound from the dry bearings, which are the cause of the cap rotating.

If you have a zerk fitting in your replacement u joint here is a tip that will add life and miles to the u joint.

Grease them BEFORE you install. Grease and exercise the joint, repeat untill you get visible grease past the seals.

What I often do is remove the caps and grease the joint insuring I have a good amount of grease out of each axle. U Joints are notorious for getting air locks and typically when we grease them at the first sign of grease we stop. If you will take off the caps and fill the grease tunnels, the replace the caps by pushing and turning as you put them on. Exercise the u joint by rotating the caps while adding grease, the allows the air to escape.

 

Good advice Don!