down to the “MOTOR HOME” row to get the degree setting. This is the initial point for
the CASTER setting. This chart is from the 1995 “Chevrolet Motor Home Chassis Service
Guide” for the P Chassis but applies to all manufactured.
Note the various vehicles in the first column that use the P Chassis. Also note that there is a
separate line for the MOTOR HOME version. It is different from the “P-20, 30” line. There
is a distinct possibility that an alignment shop will use the incorrect numbers if you tell them
to align “my P30 chassis”. But of course, we intend to TELL them the CASTER angle we
want – once we go through this entire process.
INCHES 1 1/2 1 3/4 2 2 1/4 2 1/2 2 3/4 3 3 1/4 3 1/2 3 3/4 4 4 1/4 4 1/2 4 3/4 5
G-10, 20
3 1/2° 3 1/4° 3° 3° 2 3/4° 2 1/2° 2 1/4° 2° 2° 1 3/4° 1 1/2°
G-30
2 3/4° 2 1/2° 2 1/4° 2° 1 1/2° 1° 3/4° 1/2° 1/4° 0° -1/4°
P-20, 30
3° 2 1/2° 2 1/4° 2° 1 3/4° 1 1/2° 1 1/4° 1° 1/2° 1/2° 1/4° 0°
CLASS A
MOTOR
HOME
(32 – 52)
5 1/2° 5 1/4° 5° 4 3/4° 4 1/2° 4° 3 3/4° 3 1/2° 3 1/4° 3° 3°
3” ride height and 5 degrees setting is the standard.
But wait! This may not be the final version of the degree setting you will use for the
CASTER. The “frame angle” measurement will affect the caster setting.
Frame Angle
OK. Here is how the frame angle is measured:
1. Park the motor home on a level surface.
2. Place a protractor with a level gage against the bottom of a straight section of the frame
rail near the chassis midpoint. (See illustration below)
3. Determine the angle the frame rail slopes from level.
4. Use the previously-determined caster setting from the table above as the starting point.
5. Compute the actual caster setting from the frame angle and caster measurement taken as
follows:
Main Body Page 15 of 38 Total Pages
