Preheat grill to 250° using hickory or oak for smoke flavor.
Make the glaze by whisking orange marmalade, orange juice, a spoonful of mustard and garlic together in a medium bowl. Set aside.
Pat ham dry with paper towels and place cut side down onto a baking sheet.
Score the ham by making 1 inch deep slices across the entire ham about 1 inch apart. Turn the ham and make slices in the other direction, creating a crosshatch pattern.
Stick cloves into the ham.
Use a foil pan or create a foil boat using heavy duty aluminum foil. Place the ham onto the foil pan, cut side down, scored side up.
Pour half of the glaze over the ham.
Cook the ham over indirect fire with the grill closed.
Baste ham, using a silicone brush with the glaze from the bottom of the pan in 30 minute intervals.
When ham reaches 150° using a digital thermometer, pour the remaining glaze over the ham and continue to cook until internal temperature of ham reaches 165°. Total cooking time will depend on the size of your ham.
Remove from grill and set aside to cool 20 minutes before slicing.
Move to a cutting board and carve the ham into thin slices using a sharp knife.