Newbie to the forum. I had searched everywhere on how to fix this but was unable to find any info online. So I dismantled it and figured it out, heres the fix.

My 03 Vinson park brake would not work when I moved the lever to the "Park" position. The lever moves a cable which is linked to the "front extension" of the rear differential. The cable was working fine and is actually pretty hefty, I wouldn't envision this failing.

The cable pulls a shaft which turns a cam inside the diff cover. This cam engages a "dog legged shaped" lever that locks against the drive shaft. This lever is what broke on mine. It broke at the pivot point on the bottom where the shaft goes through. It appears to be a very weak design to me. I wouldn't be afraid to pull the cover off to inspect yours, there are no parts to jump out at you. I would loosen the top bolt first that houses a locater pin & spring first though (it only goes back together one way).

If yours hasn't broke yet, I would recommend rocking / rolling your machine until it slips into Park easily. Also, I wouldn't Park on a steeper incline as this puts a lot of weight on this small lever.

Hope this helps someone else keep their 600 pound machine where is is supposed to stay.