Ideally, the scrub radius is as small as possible. Normally, the SAI angle and the centerline of the tire and the wheel intersect below the road surface, causing a positive scrub radius. With struts, the SAI angle is much larger than the long arm/short arm type of suspension. This allows the SAI angle to intersect the camber angle above the road surface, forming a negative scrub radius. The smaller the scrub radius, the better the directional stability. Installing aftermarket wheels that have additional offset will dramatically increase the scrub radius. The newly installed wheels may cause the centerline of the tires to move further away from the spindle. This will increase the scrub radius.
A large amount of scrub radius can cause severe shimmy after hitting a bump. Four-wheel drive vehicles with large tires use a steering damper to compensate for an increased scrub radius. Scrub radius is not directly measurable by the conventional methods. Scrub radius is projected geometrically by engineers during the design phase of the suspension.
Replacement Wheels Description
Spare Tire Kit InstallationDriver or Passenger Seat Back Cushion Frame Replacement
Driver or Passenger Seat Back Cushion Frame Replacement
Callout
Component Name
Preliminary Procedures
Remove the driver or passenger seat. Refer to Driver or Passenger
Seat Removal and Installation
Remove the front seat c ...
Special Tools
Illustration
Tool Number/Description
207649
Rod Hairpins
547324
Flange Screws
EN-232
KM-232
J-21867-L40
Oil Pressure Check Adapter
...
Oil Pan Replacement
Special Tools
EN-49980 Guidance Pins
For equivalent regional tools, refer to Special Tools.
Removal Procedure
Remove the right front wheelhouse liner extension. Refer to Front Wheelhouse
Liner Inner Front Extension Replacement.
Remove the oil filter and drain the engine oi ...