A: This is a universal trunk that is made to be used on a wide range of utility ATVs. It does not have a specific model fitment. You should have no problems fitting this Moose Rear Storage Trunk on your 2014 polaris 400. I would recommend comparing the measurements ( 37"W x 17"D x 14-1/2"H.) to your quad. This trunk easily mounts to tubular or composite racks with supplied hardware. Feel free to give us a call at 888-676-8853 and we would be happy to help you out with your order.
Q: Does this trunk fit inside rear rack or is rack removal required?
A: Yes, this trunk would come with the mounting hardware to mount the trunk to your ATV. The Yamaha storage trunk is very similar to this, both trunks have the same basic dimensions. Either Trunk would be a great choice for your Yamaha Grizzly.