I have a 2000 Monaco Signature that we love. We were in the process of putting 3rd set or tires on the coach when we were told there was a problem with the wheel studs. We had replaced a few of these over the years but this time we need to do all 60 of them and the nuts on the back. After doing research and getting varied answers I contacted Meritor and got an experienced tech who sent us their PDf file on maintenance. In the file we found the following information.
Installing Double-Ended Metric Wheel Studs
with 3/4-16 and M22 x 1.5 Threads Onto Hub
and Rotor Assemblies on Axles Equipped
with Meritor Air Disc Brake Model ADB 1560
Important Note: The 390-450 lb-ft (529-610 Nm) torque
specification provides sufficient clamp load to install a hub-piloted
wheel on one end of the double-ended wheel stud and not exceed
the torque capacity of the 3/4-16 threads on the opposite end. The
wheel stud is a standard design and has been in production since
Use this specification rather than 450-550 lb-ft (610-746 Nm),
which is usually specified when installing hub-piloted wheels.
Tighten the inner 3/4-16 nuts to 100 lb-ft (136 N m) to seat
the wheel studs.
Every place we had used to work on tires/wheels thought they should use the regular torque spec for trucks and buses 450-550 and some more.
To make a long story shorter the techs at Meritor and the shop where it is getting fixed agree that over the years shops over torqued the studs and eventually stretched the stud and the threads to the point they got loose. Once that happened the stud needs to be replaced. At this point we inspected all the studs and found most had issues so do them all. These studs are $50 each plus nut and all the labor.
So if you have this setup be aware that tire shop staff do not know of this.