You might be in luck by asking that question. I own a Huskee 42" cut, 18 HP garden tractor too.
Now, tell us which "bearings" you are referring to, because there are too many on the tractor for anybody to "guess" which bearings you are talking about.

I guess that would help. Not sure if they are called deck bearings or blade bearings, when I engage my blades that is when I hear the noise.

The bearings in that place are the "blade spindle" bearings.
These bearings can be replaced, but there are a few "stumbling blocks" to get past in order for YOUR spindles to be repairable.
First, the bolts which hold the spindles to the deck are often corroded and seized in the spindle itself, and will break off when you try to remove them, leaving the threaded portion of the bolt in the spindle.
Another problem that is encountered about as often as the bolts issue is whether the spindle housing, or the spindle shaft, or both.................have worn too badly for new bearings to actually affect an improvement in the situation.
To check for wear to the spindle housing and/or the spindle shaft, remove the deck from the tractor, remove the belt (it would be wise to take a picture of the belt routing or sketch it on a piece of paper) and stand it up so that it leans on something stable in order for you to wiggle the blades to check for looseness in the spindle and to spin the blade to listen for "bearing roar".
After you get the deck securely leaned on something, give each blade a spin. If you hear a growling noise or bumpety sound, bad bearing.
Now, put you hand on the tip of a blade and push the blade tip toward toward the top of the deck (top, as if it were in place on the tractor) and then away from the top of the deck. If your blde tip moves in and out as much as 1/2" or more, it might mean your spindle is not worth rebuilding, but don't quit just based on that.
Next, put your hand on the blade right where the nut holds the blade to the spindle shaft and push straight in and then pull out on the blade. If you detect as much as 1/8" in and out movement, it might indicate too much wear in the spindle housing for a rebuild.
Now, first, remove the pulleys (if you have an impact wrench it is the easiest way).
On most applications, the blade and its spindle shaft can now be withdrawn from the spindle with blade still attached.
Beware that the spindle lower bearing and a spacer sleeve will probably come out with the shaft.
Once the spindle shaft is out, slip the lower bearing and spacer off the shaft.
Inspection time: Roll the bearing and feel any roughness or see any movement or play between the inner and outer races of the bearing?
Inspect the spindle shaft where the bearing inner race rides, is their a deep groove worn in it from the bearing?
Take the bearing and slip it back into the spindle housing:
Does the bearing fit the spindle bore fairly tight or does it kind of wallow around?
If you detect either a groove deeper than about 1/32" on the spindle shaft, you probably will not want to spend your money on new bearings.
If your bearing does not fit pretty snug in the spindle housing, the same remark about bearing money applies as well.
Inspect the upper bearing (still in the spindle housing) for for the same wear in the same places as the lower bearing. Apply the same criteria for rejection or reuse of parts as the lower bearing.
Repeat this for each spindle on the deck.
If you feel you can reuse/rebuild any of the spindles, clean up a bearing in solvent until you can read the numbers of the bearing. The numbers you find are "Standard bearing numbers" and you can use the number to search by phone or web for replacement bearings.
If you can't read the number on any of the bearings you have, take a bearing to a bearing distributor type store and let the staff measure the bearing for a replacement.
But, if any/all of your spindles are not salvable......... you will need new spindle assemblies.
If you are able to salvage your spindles, just clean up the spindle housing while its still in place on the deck, and the spindle shaft with blade still attached.
Leaving the spindle housing in place on the deck circumvents the chance of having a mtg bolt break off.
If you must replace a spindle assy, use an impact wrench to remove the blade nut from the spindle.