My 2019 uforce 500 has not given me any trouble at all. until now.  while plowing snow here in Mich I put the unit in reverse and it started loud clicking or thumping from under the bed.  loaded the unit up and to the garage we went. on checking the ujoints I found that the bolt that holds the bevel gear assy in the rear drive decided to break. this holds it all the bearings and to the coupler with out it every thing inside starts moving around and makes a heck of racket.  I believe I can fix it if I can get it out of the diff with out too much trouble.  Question is has anyone else had this issue?  If you did what did you do to fix it?  replace the whole gear or just drill and tap the bolt out?   attachment is a diagram of the issue.  bolt #2 is the one that broke. 14 is the bevel gear.
UPDATE: After disassembly and diagnoses I found that the inter bearing had disintegrated.  I assume that after the bearing went it cause excessive movement of the pinion which in turn stressed the bolt causing the break. Strange thing is by the looks of the bearing and the internal housing its been gone for some time.  I never heard or noticed any issue until it broke the bolt. makes me wonder it hasn't been bad since just after first break in as there was no change in noise or drive. haven't replaced or even checked the gear oil since break this last summer but no shaving in the oil then. The pinon and bearing retainer along with coupler are all attached together via the bolt so it stands to reason the bolt was the only thing holding this thing together since the bearing went. that alone is a testament to these little machines. Bearing goes out and the thing will continue on until it breaks another part.  was able to drill and tap the rest  of the bolt with out much issue. came right out.  Now on to the replacement parts and repair.

[2015 Z Force 800 53/Trail EPS]

Now that's a first...but..I'm not surprised. Might just find you can back it out by hand. If not I'm sure an ease-out will get it.

Try with a small (say 1/8") left hand drill about 1/4" deep, then with a bigger left hand drill and you should be able to get it out when the bigger drill 'bites' into the bolt. Replace with a high tensile bolt from an engineering shop.

Try with a small (say 1/8") left hand drill about 1/4" deep, then with a bigger left hand drill and you should be able to get it out when the bigger drill 'bites' into the bolt. Replace with a high tensile bolt from an engineering shop.

Drilled and tapped it out with no real issue (got lucky). Going to use a grade A hardened 10m bolt with a 1.25 pitch at 20mm long.  that should do it as there shouldn't be any real torque on the bolt itself.

[2015 Z Force 800 53/Trail EPS]

Try with a small (say 1/8") left hand drill about 1/4" deep, then with a bigger left hand drill and you should be able to get it out when the bigger drill 'bites' into the bolt. Replace with a high tensile bolt from an engineering shop.

Drilled and tapped it out with no real issue (got lucky). Going to use a grade A hardened 10m bolt with a 1.25 pitch at 20mm long.  that should do it as there shouldn't be any real torque on the bolt itself.

Metric bolts have a different hardness rating then SAE. You will want one stamped on the top with a number 8.8 - 12.9 although a little less wouldn't be a deal-killer.. and I think you will want to torque it to around 52-55ftlbs (I might be tempted to go closer to 60) and use a thread locker.