Front End and 4WD

[Neal Gass]

Just when you think your done- another issue.

I have an situation where when in 4wd the truck functions fine (mostly to pull my boat out of the water at the lake) no issues.

The problem is that if I turn either left or right while in 4wd the front end shudders pretty violently. When I straighten back up its fine.

I got the truck off the ground and ran it in 2wd and 4wd with the wheel straight ahead. All worked fine until in 4wd if I turned the wheel either right or left the front end began to shake as if something was out of balance but in a big way. I straighten back out and all is well.

Seems like something is majorly wrong here. The front differential fluid is up tp the fill hole and nothing seems loose or broken. It goes in and out of 4wd easily with no issue.

If anyone has any ideas or has had this happen to them I would truly appreciate and help.

Thanks Neal

 

My truck details again:

2001 Dodge 3500 5.9 Diesel 4x4 Dually 
Automatic Transmission 
All Stock NO Mods 82,000mi

[Me78569]

how are your ujoints?

[Neal Gass]

They look fine and show no play or damage but I'm really not sure how to properly test them.

If they are bad is it obvious by looking at them?

[Threadzy]

If you see any movement in the joint where they  go into the cups they are toast. Everything should be tight. Check the front drive shaft as well. 

[Joe_Pool]

Also check that the CAD collar is fully engaging (if CAD equipped).  May be "floating" in a turn position if not fully engaged and jumping on the teeth.  The floor shifter may be moving easily, but the vacuum actuator may not be fully engaging the axle lock collar.

[dripley]

Are on concrete while turning the wheels? If so the drive line will bind since the wheels are not turning the same speed.

[Tractorman]

5 hours ago, Neal Gass said:

The problem is that if I turn either left or right while in 4wd the front end shudders pretty violently. When I straighten back up its fine.

 

If this is happening on asphalt or concrete, what you are talking about could be quite normal.  The front axle shafts do not have constant velocity u-joints (CV joints).  Consequently, when the steering is turned sharply in either direction, each tire will speed up and slow down twice in one revolution due to the steep angle of each u-joint per axle shaft.   With excellent traction on asphalt or concrete, the front tires develop severe wheel hop because something has to give.  And furthermore, since the transfer does not have a differential, there is also binding between front and rear axles, just not as severe. 

 

- John

[Neal Gass]

It does this even when the truck is on the hoist with the wheels off the ground.All 4 spin when I go into 4wd but It is really so noticeable and violent it seems it can't be right.

[Mopar1973Man]

5 hours ago, Neal Gass said:

They look fine and show no play or damage but I'm really not sure how to properly test them.

If they are bad is it obvious by looking at them?

 

Pull both shafts and inspect them closely. I just had my passenger side start ticking randomly. One day I tore it down to find out the u-joint appears fine but after a closer look I lost a clip on one cap and the cap was backing out. Then on top the bearings where gone on the bearing across from it. More obvious when the shaft is out and your able to move it around more in your hands and feel the slop.