Meritor — RHP/MPA

Description

These trailer suspensions have a parallelogram design with parallel upper and lower control arms. Both upper and lower control arms are bolted to a central V-shaped frame bracket instead of having two separate trailing arms. The air springs mount directly over the axles for a smoother ride, elimination of roll torque and to prevent dock walk. The upper control arms are held together by a torque tube designed to control lateral roll. Approved applications include pup trailers, dry van and refrigerated van.

Tech Tips and Additional Resources

Identification:

RHP, manufactured through 2007, has solid face on frame bracket. MPA (Ride Sentry), produced 2007/2008 through current has open triangle on central frame bracket face.

ATRO’s long-life bushing replacements:

ATRO’s upper control arm bushings offer chemical resistance to environmental factors and easier installation compared to a bonded rubber bushing. ATRO’s 1- and 2-piece designs both allow controlled motion of the upper control arm without causing bushing windup because the poly bushings are not bonded to the inner sleeves. In the lower torque rods, this free-rotation design eliminates bushing windup along with shear and torsional stresses from the torque rods.

ATRO parts for upper control arm:

Swipe table right for columns.

SU99-39113	One-piece pivot bushing	8 per vehicle	no hardware	OE #A1225L1416, A1225G1437
SU99-39114	Upper control arm service kit	2 per vehicle	hardware and 4 SU99-39113 included	OE # KIT11300
SU99-39115	Two-piece pivot bushing	8 per vehicle	no hardware	OE # KIT11126
SU99-39116	Upper control arm service kit	2 per vehicle	hardware and 4 SU99-39115 included	OE # KIT11101

ATRO parts for lower torque rod (lower control arm):

Swipe table right for columns.

PL1118	Two-piece torque rod bushing	4 per vehicle	no hardware	OE# M3032502E
TH99-37102	Torque rod service kit	4 per vehicle	hardware and 1 PL1118 included	OE # KIT11102

Torque specs: (unless otherwise specified by OE for specific suspension model)

Upper and lower control arms torque to 540-560 ft-lbs
Exception: upper control arm, side plate end – roadside torque to 590-610 ft-lbs
Lower control arm clamp bolts torque to 160-170 ft-lbs after aligning axle