Problem with the 4wd in 2007 Ford Ranger

lakken7

My 2007 Ford Ranger is having problems with its 4x4. I can turn the know on 4h and 4l and they both seem to engage. The dash will display that they are on. However, when I have either the 4h or 4l on, the truck kicks like we're going over a bump that isn't there. This happens at any speed. When the truck kicks, it will jerk back a bit. It almost seems like it's coming from the right rear wheel but I'm not too sure. Any help would be appreciated. Thank you.

Mr_Shiftright

I would check the u-joints on the axles...if they are frozen or worn the two axles opposing each other won't spin at the same rate. You might feel this when there's a road surface with no slippage.