Challenger was once owned by Caterpillar, but is now owned by AGCO. Challenger tractors are still CAT powered. The MT875C is rated at 585hp, and 425hp at the PTO. Challenger is celebrating 25 years of tracked tractors, and have a limited edition version of the MT800C series tractor, check it out here.
This model was based off the 865 and has PF features, two m motors for drive. One m motor each for PTO and 3pt hitch. Also there is a video of the functions at the bottom.
This is where I put the drive motors, This was to make more room under the tractor.