On the workhorse chassis I believe they use a drive shaft parking brake.. Look at the transmission end of the drive shaft.. If there is a brake drum on the transmission end then you should see a lever on that brake drum possibly with a cable or some such going to it.
That's device that connects the cable (or rod) to the arm is the clevis
If you got it, you got it,, Very easy to see.. I might be able to snap a photo tomorrow if you need (Will check back in about noon) since it's easy to spot and I've been there and done that.
Home is where I park it!