For vehicles operating in harsh environments with potential to expose the coupler to corrosive or caustic materials, the following
inspection shall be performed at least once per year.

1.

Remove the cotter pin, slotted nut, and washer from
the pintle (Figure 1). Clean all rust and debris from the
slotted nut and coupler threads.

2.

With a caliper or micrometer measure crest diameter
at multiple points around the circumference within
the original nut engagement zone (load-bearing
thread area) (Figure 1). If any position on the thread
under the nut is less than 2.215” (56.26mm) the nut
and coupler body should not be reused. Replace worn
components using parts kit RK-T-551.

3.

Inspect the thread profiles of both the coupler shaft
and the nut prior to reuse (Figure 2). Closely examine
the threads beneath the nut bearing surface for signs
of wear or corrosion.
Note: Rust can remove material from the threads that
carry load. As material is lost, fewer threads are
available to support the applied load. This may result
in wave-like or distorted thread crests, uneven wear
on one side of the threads, or thread crests that
appear shorter than surrounding threads (Figure 2).
Components showing these conditions should not be
reused.

Figure 1

Measure outer thread
diameter under nut

Bad threads

Good threads

Figure 2

Thread tips look
wave-like or distorted

Thread has excessive
wear on one side

Do not operate the vehicle if
excessive corrosion-related damage is present on the
coupler threaded shaft or retaining hardware.
4.

Reinstall the nut in its original position, without the
washer, and check for fit on the threads (Figure 3).
Apply hand pressure to the nut to check for
movement. Slight movement due to normal thread fit
is acceptable. Reject the components if movement is
clearly excessive, including visible rocking, looseness,
or separation between the mating thread surfaces.
If the nut or coupler exhibits any of
the conditions described above, both components
must be replaced. Failure to do so could result in
tractor-trailer separation, causing death or serious
injury. Replace worn components using parts kit
RK-T-551.

Thread tips visibly
shorter than other
threads

Confirm nut does
not have excessive
movement

Figure 3

Note: If parts pass inspection, the coupler can be
reassembled using the following procedures.

1

XL-PH20103SB-en-US Rev-

Remove slotted nut and apply a thin coat of paint to
the contact surfaces of all parts before reinstallation.
(Be sure coating is thoroughly dry before reinstalling
to avoid coating peal and binding).

2.

Ensure that the coupler body is fully seated in the
housing with no gap between the rear bushing and
coupler flange (Figure 4).

3.

Re install Washer, and slotted nut until they contact
the steel bushing removing any gaps, do not over
tighten (Figure 5).

4.

Advance nut clockwise, until the next slot in the nut
lines up with the hole in the coupler body (Figure 5).

5.

Secure the nut to the coupler body by using a new
5/16” x 3 ½” cotter pin. Fully bend over both legs of
the cotter pin as shown (Figure 6).
Failure to properly install the
cotter pin could result in the nut and washer coming
loose resulting in tractor-trailer separation, causing
death or serious injury.

No gap between
steel bushing &
coupler flange

No gaps between nut,
washer and steel bushing

Figure 4

Figure 5

Figure 6

safholland.com

SAF-HOLLAND, Inc.
Tel 800.876.3929
SAF-HOLLAND Mexico
+(52) 55.5362.8743

2

SAF-HOLLAND Canada Limited
Woodstock 519.537.3494
Cambridge 519.621.3924
Surrey 604.574.7491

XL-PH20103SB-en-US Rev-

XL-PH20103SB-en-US Rev – 2026.05.26 • Amendments and errors reserved ©SAF-HOLLAND Inc., SAF-HOLLAND, HOLLAND, and SAF-HOLLAND Original Parts
logos, are trademarks of SAF-HOLLAND S.A., SAF-HOLLAND GmbH, and SAF-HOLLAND Inc.

1.