Even though this thread is about a year old, and no one ever responded; I thought I could answer this, in case anyone else came along with the same question. I hope the OP has already figured this out by this time.
Assuming everything was installed correctly, all bolts were correctly tightened, AND cables, hooks, and appliances are properly stowed, to prevent movement and banging when in motion; the following is often overlooked by owners when selecting an aftermarket bumper.
The weight difference between the weight saving factory bumper or plastic bumper covers, whatever the application, and an aftermarket winch bumper is significant. This extra weight is very taxing on a stock front suspension; this causes a lot of extra movement in suspension components when going over rough surfaces, like potholes, etc; this likely is causing bottoming of one or more suspension components.
When installing an aftermarket bumper, especially one with a winch, ensure that you also upgrade the suspension to compensate for the additional weight. From personal experience as an ASE Master tech and service manager, I have seen incorrectly optioned vehicles break springs, and other suspension parts due to the extra weight of heavy bumper / winch configurations; some bumper / winch combinations can add hundreds of pounds to the front or rear of a vehicle.
In addition to the extra weight, because the bumper is the furthest point forward, or back of the vehicle, a weighted fulcrum effect is in play, which actually increases the force of movement caused by the additional weight of the new bumper; remember, the factory engineers equipped your trucks suspension to handle the forces generated by the lighter weight factory setup.
When planning an addition to your vehicle, such as this, it does not hurt to ask reputable vehicle upfitters; such as those that build tow trucks, emergency service vehicles, and the like. Make a few phone calls, send an email to ask, ar read their detailed marketing information, to determine what suspension changes they make when adding the desired component; they do not usually keep that information secret, as they will use it as a selling point for their product.
