Originally Posted by SPGremlin

This is the right direction - but this is not enough to get a properly working freewheel hub! One more step is needed. Otherwise, the hub will freewheel but there will be a very late gear engagement (on all 3 gears - especially on the low gear), with a very noticeable pedal "slack" - nearly half a turn of a chainring will be required to engage the gear after even a small a period of freewheeling (or when starting movement).

After removing the brake pads, one needs to put something elastic around the 6 rollers to push them in and hold them together (like the original brake pad assembly did), such as:
A keyring of a proper size
or
A rubber plumbing o-ring like they sell in Home Depot
or
Perhaps a zip tie (if it is small enough that its head will fit in and won't touch the hub shell
I have an image of how it looks like (in my case, it was a keyring) - but being a new member I can't post it here (URLs and Images are prohibited). It is attached to my reply on similar question on the MTBR forum - you can find it by searching.

That piece (whatever you chose it to be) does not need to be very strong. Its function is to exert sufficient pressure on the rollers so that it was "easier" for the hub to ratchet (carrier unit against the hub shell) while freewheeling or backpedaling rather than to drag and attempt engage the brake roller clutch. Without this piece, any freewheeling will rotate the roller clutch inside the carrier unit as if the brakes were engaged (though there are no brake pads so no braking will actually occur). By default (without anything pushing on the rollers) it is "easier" for the hub internals then proper ratcheting. Then subsequent pedaling will need to undo all that rotation before the gear is engaged, and it results in a very noticeable pedals slack.