Yep, I'm a newby. I took apart my Bafang fat tire motor (800 miles since new) to grease the gears it because it was starting to make some noise during acceleration (kind of a gear whine). The gears look great and gear alignment is good. I am 72 and drive the bike easy on relatively flat trails. after dis-assembly I noticed that when trying to turn the gear/clutch, the gear/clutch is quite hard to turn and when I turn the gear/clutch it has a harder bind (more difficult to turn every few degrees of rotation)(turning in either direction)(this feels like the nylon gears are too tight on the main motor gear. There are no clicks or notch-feeling) so I don't think it's a bearing). I'm wondering if this is normal? The gears are quite greasy, so I'm suspecting this might not be a lack of grease issue??
Also before taking apart, I noticed that the bike rolls forward easily1, freely, but when rolling backward, the rolling is "stiff" (doesn't roll backward as freely as rolling forward). Wife's identical e bike rolls easily, freely backwards. It's not making any noise yet.
Also, where can I buy a gear/clutch assembly for my Bafang fat tire motor (maybe a 500W motor??)

Many bafang fat tire motors are G060 models. Should be a label on yours. Gear clusters are sold by a lot of people. Here's one from walmart's consortium of vendors. Count your teeth and verify the dimensions,

You'll also find sellers on Amazon, ebay, aliexpress.
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I own several bafang hub motors, including a G060, but haven't seen any problems that warranted opening it up.

I selected the question and clicked "Search Google for" and saw plenty of places to order the assembly.

I pulled my gear/clutch and measured. Gear/clutch sets being sold on various websites have dimensions that don't exactly match my gear measurements. Example - every website measuring the span across two gears states 3.46" (mine are 4.22"). Every Website states OD of one gear 1.87" (mine measure 1.925"). All measured with precision calipers.
My gear set is VERY hard when I try to rotate the assembly while mounted on the motor shaft (like they're in a bind or just too tightly pressing on the motor shaft gear). I'm wanting to switch out my gear/clutch because on gear's bearing is bad.
I'm very interested in your thoughts

Before you opened the motor, it is normal for the wheel to roll forward with low resistance. The clutch in the planetary plate engages when you spin the wheel in reverse. Is it possible that the gears were reassembled with a piece of debris hidden in the new grease that prevents one of the gears from spinning. My tub of bearing grease has been around for 30 years.. I'm lucky it's not full of dirt.

I bought this planetary 9 years ago for a Bafang SWXH motor, half expecting that I would melt the existing gears. Sanity ruled. I never melted them. The gears spin freely, but the keyway section only rotates in one direction. You might recheck that.

Rad Power Bikes has verified that it's a 750W Bafang hub motor. My gears on the clutch are larger than what I find for a 500W-750W gear/clutch set. I think I've found a gear clutch set that is closer in size (but not quite) to my set, and it's for a 750W-1000W motor.

This task of finding a gear clutch set has consumed hours and hours of my time. Since my gears are OK, I've since discovered that the gear bearings can be changed (I found one bad bearing on my gear clutch set).

So I am changing all 3 bearings to high quality bearings which I believe will correct the noise. I will continue to casually search for a gear set that matches my size (gear OD 1.93" (49mm). Gear spacing (across two gears 4.26" (108mm). Gear spindle/axle spacing 3.0" (76mm).

If anyone stumbles upon my sizes, please let me know. THANKS!