2008 4x4 dodge ram big horn edition. front end rattle on driver's side when driving over bumps/cracks in the road, more apparent when driving slower speeds

check steering ball joints for wear. Check for loose wheel bearings. Check front end suspension

check your ball joints and sway bar links

you may just have bad u-joints they can cause vibration when driving you can or may hear a clunking sound when you put it in gear.

Its a big possibility that you have a set of bad struts on you front end.Also take a look at your lower ball joints to see if they are damaged any.

Interesting problem although aggravating. Take a bottle of Dawn washing up liquid,(or equivilent) and drive the vehicle to the nearest railroad crossing. Squirt the soap all over the mounting rubbers on the shocks and anti roll /sway bar. Drive across the railroad crossing and listen for the noise. if none then you have narrowed the search. next do a simple process of elimination regarding the soaped rubber mountings etc.
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However,a Dodge noise making rattle when crossing any uneven surface can be caused by the front grille securing fixtures coming loose and allowing the grille to rub and vibrate on the sheet metal. I have an older Dodge with stainless steel wiring fitted to resolve that same problem! It's not an obvious fault but it really is an aggravating one.

If your not hauling a load reduce you tire air pressure, will give a little more smoother ride, also under braking have your front brake rotor checked they might be wrap.

look at the front lower engine mount. I had similar noise which has been driving me nuts, thought may be thesway bar links, put it on friends hoist and saw that the front engine mount (mounted to bottom of lower radiator support) was cracked and the rubber bushing inside very worn with pieces missing. odd thing is that reving, or putting into gear never caused it to make a noise, just certain bumps. I ordered part from Autozone,hopefully it gets here before the holiday week end is over.
Good luck

check your break pads, and calipa. check your wheel balancing and alignment

You may have bad CV joints located just behind the brake rotors and at the end of the axles. Check for bad wheel bearings while you are there. Hope this helps!

That noise sounds to me like a Ball Joint problem. I would check to see if you have fittings to grease the front suspention.

Good luck, Allen