Super LOUD bang in 4wheel drive

[DHBPhoto]

Hi guys —

Before I start, no I do not have audio or video of this happening, but it's consistent enough that I took it into the dealership and they were able to replicate the noise, and have acknowledged its an issue. They've been chasing it to no avail.

Here's the deal:
- I have to put my truck in 4h to back my trailer across my lawn / gravel so I don't dig holes. The first time I heard the noise was when I was pulling back onto concrete, turning right, and bang, a loud pop.
- Since then I have heard it when doing technical 4wheeling when the wheels are turned one way or the other (and more consistently to the right). It never does it driving straight in 4wheel drive, whether on concrete or offroad.
- If I put the truck in 4hi and back up with the wheels turned to the right, especially on a slight grade, it was pop every few revolutions of the tires. And no, this is different from skipping because I'm in 4hi on pavement.

Tech's thoughts:
- Lower Control arm. They replaced it (or some parts). Still does it.

My thoughts:
- My skid plates. In the past, I've had noises from skid plates that were not torqued all the way. I tightened them and still have noise.

Any other thoughts?

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[XLT22]

Sounds like driveline windup more than anything. It can happen on surfaces other than pavement just not super common.

Are you shifting to 4WD while stopped? Yes I know technically you "can" it's easier on the transfer case if you're rolling even 1mph.

 

[ak49rzrs]

So if understand correctly, your were in 4hi when pulling back on to concrete (dry concrete?) and turning right? If so it's possible you messed up a CV and it's going to eventually leave the chat whichever on it is. A bad CV will do what you describe of no noises going straight, but makes noise when turning. And if it's dry pavement your driving on, you should never be in 4wd.

 

[Aonarch]

Definitely sounds driveline related. A lot of techs are hopeless without a code.

 

[Hans Moleman]

That noise is your drive line being tortured to a horrible death on by using 4WD on dry pavement

 

[Tall Tail]

Is the noise from the front, middle, or the rear? from the side or underneath?
Do you feel it or just hear it?
Do you have a front or rear locker or LSD?
Is it engaged, maybe inadvertently?
Do you have a lift, bigger tires, or any mods?
Do you have the max tow package? I am sure the dealer would have found your sheared axel bolts.
Has the dealer sent you pics of your diff gears?
Have you checked your front and read diff oil levels, xfer case oil level, and your trans oil level?
There was another post on the forum about a guy who backed up a trailer in 4 Hi and sheared his axel bolts on a max tow as i recall. you can search the forum and find the post.
I think there was another post about an issue with an axel sleeve (loose?) modifying fixed something?

 

[FaaWrenchBndr]

Using four-wheel-drive, on pavement, and turning, create a driveline bind. The CV joint is getting stuck and bound up because you’re on asphalt or concrete and the tires will not scrub because of the turn that is required by the CV joint.

The clicking you were talking about at the end is due to a damaged CV joint. You’re gonna need one or two CV shafts to fix the problem.

 

[Davexxxx]

This is why I don't buy used FWDs

 

[Gros Ventre]

The U-Joints in the front axle/driveline, are snapping when the wheels are put over in a turn. That's why it doesn't occur when steering straight. Reduce the angle of turn to half of what you're doing and it'll go away/ get much milder. U-Joints do that when put over in a hard turn.

 

[thiggins]

Could be the front axle hub engagement (splines) letting go, or not engaging correctly. I've had similar noises in the past. Bad seals , vacuum leak, bad vacuum, needing cleaning/grease,...They do pop .

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[tmark]

The U-Joints in the front axle/driveline, are snapping when the wheels are put over in a turn. That's why it doesn't occur when steering straight. Reduce the angle of turn to half of what you're doing and it'll go away/ get much milder. U-Joints do that when put over in a hard turn.

THANK YOU. My 4wd does that when turning tight. My buddy’s Silverado did the same thing so I assumed it was the nature of the beast. Will a damaged CV cause a “wop-wop-wop” sound going down the road, much like a tire out of round or the like? I’ve had that noise which sounds like it is left front for a long time, and I assumed it was the tires.

 

[FaaWrenchBndr]

THANK YOU. My 4wd does that when turning tight. My buddy’s Silverado did the same thing so I assumed it was the nature of the beast. Will a damaged CV cause a “wop-wop-wop” sound going down the road, much like a tire out of round or the like? I’ve had that noise which sounds like it is left front for a long time, and I assumed it was the tires.

A bad CV joint certainly can cause a out of balance sound that sounds like a tractor tire

 

[Gros Ventre]

Don't know about the wop-wop-wop... If you push the turn too hard you can damage the U-Joint. In my case when I sense that I ease off the steering wheel.

 

[tmark]

There is one spot I have to use 4wd and it involves a tight turn. Not too get into a lengthy explanation, but is is at the bottom of a hill with roots and pine straw. To turn around and get back up from the water is a PITA without 4wd. That is the only place I’ve heard the loud snap noise.

 

[Billflangjr]

So if understand correctly, your were in 4hi when pulling back on to concrete (dry concrete?) and turning right? If so it's possible you messed up a CV and it's going to eventually leave the chat whichever on it is. A bad CV will do what you describe of no noises going straight, but makes noise when turning. And if it's dry pavement your driving on, you should never be in 4wd.

So true !

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