He's got 2 Minicon ports under the front of the vehicle quite close together. Looking at it side on I suppose the wheels could be some form of dual cannon.
TF: Pull the front of the truck apart along the middle. On each side fold the side of the front wheel into the side of the back wheel - the front wheel protrudes where there's a depression in the back. Fold the suspension out to the sides and swing out to form the arms. Swing the wheel sections round to the front and fold down to form the legs. Fold the head up - a step the Hasbro photographer forgot for the packet photo.
Resulting robot is a near perfect Minicon. Technically he's got sideways knees as part of his TF but the wheels that form the upper & lower legs are so tightly locked together in robot mode that you can't count it as articulation - unlike the hips which move up & down and swing to the sides or his ball jointed shoulders that can swing in front of the chest. He's rectangular, he's chunky, he balances well, and represents almost everything that's good about a Minicon. Probably Best Minicon Ever.
Grindor was found in the Dirt Digger team with Dirt Rocket & Oil Slick .