4wd Engages W/ A Bang

[HD Man 16]

My truck is a 2005 2500HD, 6.0L. Has 57000 miles on it. Just recently when you engage 4wd H by pressing the dash switch, there is a loud bang if you are engaging it while moving (25-60mph). It never did this before and does not do it if the vehicle is not moving. Any suggestions?

[Mckenzie]

i dont think your suppose to engage 4wd while moving that fast

[kbswear]

i dont think your suppose to engage 4wd while moving that fast

 

I cant help you with your problem but engaging 4hi at 25 mph shouldnt be a problem. I dont normally do it over 35 mph or so.

[HD Man 16]

The owners manual states that it can be shifted "at any speed, and the front axle will lock automatically with some delay." The transfer case is the electronic one. I know you cannot do this from 4H - 4L but my problem is 2H-4H. If I shift it w/ out the vehicle moving, I do not have the problem.

[56kz2slow]

Do you have different size tires between the front and rear? Even if they are the same size, if they don't have the same amount of wear, it causes them to have a different diameter/circumference, which means that the smaller are turning the axle faster than the larger.

 

Difference in sizes can cause the system to not work properly or even worst, damage.

 

My Nissan would not shift out of 4x4 with new rear tires and 50% thread left front tires, just to give an example of weird things that can happen with different sizes.

[HD Man 16]

The tires are the same size, Michelin's 245's and are relatively new. I have had them rotated and still have the problem.