wheel will collect dirt and foreign matter. This
material may work into the fifth wheel lock-
ing mechanism, causing wear and difficulty
uncoupling. This material can also cause gall-
ing of the fifth wheel and/or kingpin plate.
If the trailer kingpin plate is not fully rein-
forced, distortion can result causing:
• Non-uniform loading
• Variation in kingpin length
• Cutting and galling of the fifth wheel
or kingpin plate
If the trailer kingpin plate is distorted enough
to cause any of the conditions listed above, it is
recommended that a new plate be installed.
The trailer kingpin plate must be properly
greased.
Fontaine Fifth Wheels are designed and
manufactured for use with all trailer kingpins
that conform to SAE specifications, SAE J700,
February 1993, and subject to the wear limits
of SAE J2228, June 1993. These specifications
cover SAE 2" (50.8mm) kingpins only.
The SAE standard kingpin can be checked using
the dimensions given in Figure H.
Fontaine
®
Fifth Wheel Handbook
13
SAe STANDArD KINg-PIN
(SAE J700, FEB 93)
All dimensions in inches
2.875 ± .005
1.328
1.250
2.782
2.704 3.354
3.256
2.812 ± .015
2.000 ± .005
Figure H
