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It is the
responsibility of the installer to ensure the slide unit is securely
fastened to a base that will provide safe and reliable operation.
The many variations in usage and placements of a slide unit prevent
specific guidelines; and the following are only intended to be
general in nature to provide awareness to the installer.
Usage
All slide units are designed for use only in a static and level
conditions. If installed in a vehicle, they must be closed and
locked prior to and during any vehicle movement. The vehicle
must be parked in a level condition prior to unlocking and extending
a slide unit.
Position & Check
Clearances
The slide unit should be set into position. However,
before attaching, check to ensure that nothing interferes with the
locatin and operation of the slide. Check to ensure that with
all compartment doors closed, there is no interference to the door
itself, lock components, gas shocks, etc. Check to ensure that
the slide extending will clear the doorway edges. Allow a
little gap (perhaps 1/2") to accommodate any slide deflection due to
loads and slight misalignments due to the installation itself.
Shims
Many vehicle compartments have a lip on the bottom of the doorway
above the floor level. Slide units may have to be shimmed up
to miss the lip during extension. Shims can be many
alternatives including wood, metal tubing, etc. The
shims must be placed under all of the slide areas that normally
contact the floor to provide necessary support.
Forces
The slide unit must be securely fastened to a base floor or other
structure to resist movement. A tipping force is applied to
the unit when it is extended, which is countered by the attachments
at the rear and middle of the unit. Furthermore, vehicle
acceleration, cornering and braking will result in forces. Impacts
due to dropping a load will result in temporarily higher forces seen
by the fasteners.
Fasteners
Typical slide unit attachment is by use of a nut, washer and bolt.
Typical size is 3/8" diameter steel bolt. Small units may go
to 5/16" diameter and heavy duty units may go to 7/16". Even
small bolts can resist large forces, but the use of a larger bolt is
advised to provide margin for any occurrence of misalignment, wear,
corrosion, fatigue, or the like over the service life. The nut
and bolt should be tightened snuggly, but not excessively as this
may result in distortion of the slide unit. The nut and bolt
must use locking provisions such as lock washer, nylon collar nut,
double nutting, locking fluid, etc. Grade 5 bolts are
typically used and are identified by the three equally spaced radial
marks on the head. After installation, at least 5 threads
should extend beyond the nut. See Base Floor Considerations
comment also.
Attachment
points
Normally, a slide unit will have 4 to 6 points to attach to the
base. A single direction slide unit must have at least the 4
rear and center points fastened and a dual direction slide must have
at least the 6 points at both ends and the middle attached.
Base Floor
Considerations
The base floor or other supporting structure onto which the slide
unit is attached should have sufficient integrity to support the
weight of the fully loaded slide unit and the ability to anchor the
fasteners attaching the slide unit to it. Down the road travel
of a vehicle will encounter bumps that will temporarily input higher
loadings. Fasteners in a steel bar base will not normally
require anything other than a normal washer under the nut or bolt
head. Fasteners in sheet metal or plywood will require
additional back up such as large fender washers or even as much as a
bar stock spanning fastener to fastener. RV compartment floors of
plastic, whether flat or convoluted, may need full width bar stock
spanners under the floor to adequately distribute the load into a
relatively flexible floor structure.
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