
XL-FW501 Rev C 3
INSTALLATION INSTRUCTIONS
continued
Installation
General Recommendations
1. Every user and installer using SAF-HOLLAND products either recommended or not
recommended by SAF-HOLLAND, must thoroughly satisfy himself that the installation
procedure used is appropriate for the vehicle, product and application.
2. Consult the SAF-HOLLAND literature for fifth wheel capacities and applications.
3. Consult the tractor manufacturer’s body builder’s book and the latest SAE and D.O.T.
standards for additional installation methods. SAF-HOLLAND recommends the T.M.C.
Recommended Maintenance Practice 603B for installation procedures.
4. Determine the proper fifth wheel position, or, in the case of a sliding fifth wheel, the range of
proper positions. Proper positioning of the fifth wheel is important for weight distribution,
swing clearance and handling characteristics. See SAE J701a for proper placement, as well as
the tractor manufacturer’s body builder’s book.
5. Use only new Grade 8, 5/8˝ minimum diameter bolts and new Grade “C” locknuts in all
mounting holes.
6. Bolt holes can be 1/32˝ larger in diameter than the bolt fastener. Bolts must be adequately
tightened using charted torque ranges in foot-pounds for the recommended Grade 8, 5/8˝
diameter bolts. Larger diameter Grade 8 bolts and coated fasteners may be used.
7. The bolts attaching the fifth wheel mounting angles to the truck frame require hardened
steel washers under both the bolt and under the locknut, unless flanged head bolts or
flanged head locknuts are employed.
8. A minimum of 5 bolts are required to attach each stationary mounting angle and a
minimum of 6 bolts are required to attach a sliding fifth wheel frame rail, and the distance
between bolts must not exceed 8˝, except when cutouts are required in the mounting angles.
When attaching an outboardangle to the fifth wheel slide plate, all mounting holes are to
be used on each side.
9. Whenever a cutout is made on the mounting angle, such as required to bypass spring
hangers, a 1˝ minimum radius should be used and bolts should be placed within 1-1⁄2˝, but
not closer than 1˝ of the cut, fore and aft.
10. The mounting angle should have a minimum thickness as shown in TABLE 1 and should be
steel specification ASTM A 36.
11. When initially positioning the fifth
wheel for frame holes, the full length
of the fifth wheel or slider mounting
angles should seat flush on the top
and side surface of the truck-tractor
frame rails wherechannel-type rails
are employed. There should not be a
gap over the top of the truck frame
rails. The base of the fifth wheel
assembly and of the mounting angle
members should seat flush on the top
of the frame rail to prevent flexing
and to give uniform weight distribution. It is also recommended to chamfer or smooth sharp
edges and corners of mounting materials wherever contact is made with the tractor frame.
12. If the fifth wheel is to be mounted using a mounting plate (bracket with mounting base),
refer to TABLE 1 for minimum plate thickness recommendations.
Do not use U-bolts in fifth wheel installations. Use only new Grade 8,
5/8˝minimum diameter bolts and new Grade C lock nuts in all mounting
holes. Failure to do so may result in structural failure of the installation with a potential loss of
the fifth wheel assembly, mounting structure, and/or trailer and could result in death or
serious injury.
13. Trailer pick-up ramps are recommended at the rear of the truck-tractor frame.
14. When mounting to aluminum frames, follow the tractor manufacturer’s recommendations.
SAF-HOLLAND has available a stationarymounting angle intended for use with aluminum
frames. Contact SAF-HOLLAND or distributors of Holland brand products for availability.
15. Review, in addition, the specific information on the following pages for each type of fifth
wheel mounting, as well as “Inspection and Lubrication Prior to Use”on page 8 of this
publication.
TABLE 1
Minimum Minimum
Fifth Wheel Mounting Angle Mounting Plate
Vertical Capacity Thickness Thickness
12,000 lbs. 1/4˝ 1/4˝
20,000 lbs. 5/16˝ 1/4˝
40,000/45,000 lbs. 5/16˝ 5/16˝
50,000/55,000 lbs. 3/8˝ 3/8˝
62,500/70,000 lbs. 1/2˝ 1/2˝
100,000 lbs. 3/4˝ 3/4˝
165,000 lbs. 3/4˝ 1˝