I've got a friend with a Guzzi Convert and Ural sidecar that has a documented 1 million miles on it. Yes he finally had the engine rebuilt but the Trans had no problem pulling a Ural sidecar all those miles. I wouldn't worry about it.
'78 BMW R100/Ural sidecar, '99 Ural Patrol
'03 BMW R1200CLC Solo & Ural sidecar Rig
'06 Honda Big Ruckus Solo & Sidecar Rig,
'08 Ural Retro, '10 Ural ST Solo