The only shipping method allowed for items 150 lbs or more is “Freight Shipping”. Any other shipping besides “Freight Shipping” will not be accepted by eBay. If any shipping errors get returned for items that are 150 lbs or more, you should check to see what shipping option is selected.

In addition, if “Freight Shipping” is the shipping method, you need to make sure the “Immediate Payment” toggle for your product is turned off: