140mower
Don
Yes, the voids are for a little bit of cushioning, and just below them are little shock absorbers......I have been working on trucks for 43 years and I have never seen a bushing like that.
The voids in the rubber are probably there to make for a softer ride.
International uses a bushing with voids in the front cab mounts on the smaller trucks but its a lot bigger
and presses into a casting.