Duetz-Allis 9170 parking brake

To inspect for the breakage, lift the cab - does not have to be removed as in cables, wiring, etc - remove the top plate and pray for the linkage to be broken. IF so it is not a picnic, but can be done from the top. IF it is the pivot bolt broke, you have to remove the bottom box, then remove the freeze plug and this allows partial access to the pivot bolt - we have been able - with one exception - to get a long welding rod carefully in and weld a nut on the reduced threads of the bolt broke off in the rear housing. It is a pain that requires patience. AGCO had a special tool they would rent or furnish to install an improved version, best of my memory that was decades ago. We caution all owners of the these units - a 1/2" bolt will not stop a 25,000 # tractor. Most damage is cause by applying the brake - which puts a pawl in a slotted disc - while the tractor is moving. i.e. with a load trying to get up a bank to the road you stop and the unit starts rolling backwards... don't use the parking pawl brake -  72160757 is the # to look for on Agco parts site. maybe the bolt came out of the linkage

I've been into a couple of tractors with failed park locks. They were both 9600 series tractors. They both used the White rear end assembly. I moved the wheels out and removed the cabs to get at the park lock. The internal linkage for the park lock is the weak link,in my opinion. The cog wheel, on the shaft, was fine on the ones that I repaired. No split required, at least on the ones I did.

Does anyone know if it’s typically the cog on the pinion shaft that brakes or could it just be the brake latch? Was wondering if it was the latch if you could just take the cab off to get to it without splitting the tractor?

No idea no help. I'm thinking cab removal and a split at a $100/hr shop is going get expensive. Hope you bought it right.