5
26
Wheel cap nuts
5-2
NOTICE: One-piece flange nuts
are not approved for use on any
Alcoa wheel application.
WARNING Use of chrome-plated cap nuts which have chrome plating on the surfaces
which contact the wheel can cause reduced and inconsistent wheel clamping.
This condition can cause wheels to loosen and disengage from the vehicle, causing
serious injury or death.
Never use cap nuts with chrome-plated contact surfaces. Use only recommended
hardware on Alcoa aluminum wheels.
There are many types of nuts and studs in use, and their design and specifications are not standard-
ized. The “R” and “L” on cap nut part numbers indicate right and left-hand threads respectively.
Alcoa recommends the following cap nuts for use with Alcoa aluminum truck wheels:
Cap Nuts
2-piece 33mm hex head flange nut.
Mounts single and dualed wheels
to wheel centering hubs. Right
hand threads used on both sides of
vehicle. Single wheels require 2"
(50.8 mm) stud standout. Dualed
wheels require 2-13/16 (71.44 mm)
stud standout.
P/N 39874 (supersedes
P/Ns 39701 and 39691);
M22-1.5 RH threads.
2 piece 1-1/16" hex head flange nut.
Mounts single and dualed wheels
to wheel centering hubs. Right
hand threads used in both sides of
vehicle. P/N 39946; 5/8"x18 RH
threads
2-piece 30mm hex head flange nut.
Mounts single and dualed wheels
to wheel centering hubs. Right
hand threads used on both sides of
vehicle. P/N 39708; M20x1.5 RH
threads.
WARNING
2-piece 33mm hex head flange
nut. Mounts dualed wheels with
32mm bolt holes to wheel centering
hubs. Right hand threads used on
both sides of vehicle. P/N 4307.32;
M22x1.5 RH threads.
2-piece 33mm hex head flange nut.
Mounts single wheels to wheel
centering hubs with 32mm bolt
holes. Right hand threads used on
both sides of vehicle. P/N 4306.32;
M22x1.5 RH threads.
1-1/8" cap nut. Mounts standard
single wheels and wide base wheels
to 1-1/8" studs. Also mounts outer
dualed wheel to 1-1/8" inner cap
nut. P/N 5996R, 5996L (replaces
P/N 5552R, 5552L).
3/4"x16 cap nut. Mounts Alcoa
wide base wheels to 3/4" studs. Do
not use on steel wheels.
P/N 5995R, 5995L (replaces
P/N 5554R, 5554L).
Inner cap nut, inner thread
3/4"x16, outer thread
1-1/8"x16. For use with
standard length studs (1.31"
[1-5/16] to 1.44" [1-7/16])
stud stand-out) or longer
studs not to exceed 1.88"
[1-7/8] stud standout.
Full internal and external
threads. P/N 5978R, 5978L (Grade 8). For studs without
exposed shoulders. Do not use with steel inner dualed
wheel.
Inner cap nut for use with
standard length studs
(1.31" [1-5/16] to 1.44"
[1-7/16]) stud standout) or
longer studs not to exceed
1.88" (1-7/8) stud
standout. Full internal
and external threads,
counter bore 5/16" deep at open end. Prevents stud from
bottoming out in cap nut. P/N 5988R, 5988L (Grade 8).
For use with studs with exposed shoulders. Do not use
with steel inner dualed wheel.
Inner cap nut, inner thread
3/4"x16, outer thread
1-1/8"x16. For use with
steel inner dual wheel
an aluminum outer dual
wheel with 1.31"
(1-5/16) to 1.44" (1-7/16)
stud standout. P/N 7896R,
7896L (Grade 8).