Mike and group answering post, add my two cents into the thoughts being passed along.
Be real careful in choosing your blocking ( hardwood is the best because it will not crush,
split etc ) Working on heavy equipment in the field for many years and supporting something
weighting 30 plus tons than working under the machine is sometimes a little unnerving.
It does not matter is it is a motorhome or a piece of heavy equipment, supporting weight
without hardwood blocking is a accident waiting to happen. A person can get 2 X 4 hardwood
blocks from old pallets that are discarded. The bad part of doing all our own repairs is
that we have a 30 year old mind with a 70 year old body and cannot move as fast like we
used to. Cannot again stress safety. Dave Atherton Retired Cat Mechanic