If I need a alternator will the car ride rough

Is there a chance that you got a lot of moisture in the alternator too? I would check that out but also look to see if the unit is still tight in the bracket and the belt is snug - all with the engine off. Whatever is loose needs to be tightened.

Often this is a A/C clutch bearing, but do not overlook the stationary idler pulley bearings which your serpentine belt rides on,

The water pump and Alternator both have bearings as well as the Power steering pump.

These bearings can be checked by slipping the serpentine belt off and manually turning the pulleys, checking for roughness in the bearing.

ride control has gone out and is in default mode.any time a problem is found it goes to this setting untill repaired. ride control module,ride sensors all need cked.

If those wheels are low-profile, they would ride rough by design, having less flexibility to insulate the bumps of the road.

I would check your tire pressure, if your running 60 psi it's going to be a bumpy ride, lower the air pressure to 35 psi and see if it makes a differance, does the truck move up and down when you jump on the bumpers or is it stiff ?

All car manufactures have illegally conspired to manufacture non-luxury cars to ride rough in order to force people into buying their high profit margin so-called luxury cars.
BELIEVE IT OR NOT!

I would suggest having the Alternator checked for the proper amp output. Although it may be making enough power to keep the battery charged, it may not be making enough to power the vehicle and still be the reason the engine performs rough at low RPM's under accessory load.

battery is getting drain and it not the alternator, fuel pump, or fuel filter

usually the shock absorb make the ride rough or soft if they bad need to be replace also make sure your tire pressure is no more than 35psi

mcdevito75 here, If you have 1 continuous belt on the engine (serpentine) then the belt could be worn or the tension pully holding the belt tight could be going bad. No noise in Neautral or Park as increased engine speed in these gears over rides the worn part and thus no noise. On a cold engine examine the belt, look for frays / wear from where the belt rides the pullys. If the belt is 2 years old, Change it.