Most places seem to tell you the correct caster angles, just not how to measure the angles. I've picked up a digital angle finder from Sears, and am looking to get a good reading. How's this process: 1. Park on level ground. Attach the angle finder to the frame of the Jeep and 0 it out. Attach the angle finder to the bottom of the. See Adjusting Jeep CJ Toe. Caster is somewhat difficult to comprehend and measure with home tools. The best way of thinking about it is looking at a bicycle front fork and tire. The forks arrive at the center hub at an angle. The positive caster allows the tire to return to center (the reason you can ride a bike with no hands). RLW007 said: I just raised my 2018 JL Unlimited Rubicon to 3 1/2 to 4'. What is the recommended caster for a lifted jeep of this height.? Running EVO coilovers with 37' Coopers and long arms.
- How To Measure Caster In Jeep Jlo
- How To Measure Caster In Jeep Jl Parts
- How To Measure Caster In Jeep Jl Wheels
- How To Measure Caster In Jeep Jl 4x4
If you've just installed a brand new lift on your Jeep JL Wrangler and are wanting to get it aligned, there are a couple of things you should know before you take it to a shop and pay to have it done. First, unless you've installed new aftermarket components such as an adjustable track bar and/or adjustable control arms, there really isn't a whole lot a shop can to other than recenter your steering wheel and take your money. Due to the design of the JL steering system, your toe-in will not change at all and being that it comes with a solid front axle, its camber will not change either. Depending on how much lift you install, your caster may be off enough to feel it but again, nothing can be done unless you've installed aftermarket components that will allow you to make adjustments. Second, even if you have installed a 2″ lift or taller and added adjustable components, doing a basic front end alignment is easy, something you can do in your own driveway, with the use of some basic tools and this write-up will show you how.
Alignment Topics
Steering Wheel Re-centering
Front Axle Re-centering
Setting Caster
Setting Toe-In
What You Will Need
• 15,18,21,24mm Socket & Wrench
• Ratchet
• Large Crescent Wrench
• Angle Finder
• Tape Measure
• Carpenters Level
• Floor Jack
• Jack Stands
How To Measure Caster In Jeep Jlo
Alignment Definitions
The following are common wheel alignment definitions as defined by Jeep and that you will need to be familiar with:
CASTER is the forward or rearward tilt of the steering knuckle from vertical. Tilting the top of the knuckle rearward provides positive caster. Tilting the top of the knuckle forward provides negative caster. Caster is a directional stability angle. This angle enables the front wheels to return to a straight ahead position after turns.
CAMBER is the inward or outward tilt of the wheel relative to the center of the vehicle. Tilting the top of the wheel inward provides negative camber. Tilting the top of the wheel outward provides positive camber. Incorrect camber will cause wear on the inside or outside edge of the tire. The angle is not adjustable, damaged component(s) must be replaced to correct the camber angle.
WHEEL TOE POSITION is the difference between the leading inside edges and trailing inside edges of the front tires. Incorrect wheel toe position is the most common cause of unstable steering and uneven tire wear. The wheel toe position is the final front wheel alignment adjustment.
STEERING AXIS INCLINATION ANGLE is measured in degrees and is the angle that the steering knuckles are tilted. The inclination angle has a fixed relationship with the camber angle. It will not change except when a spindle or ball stud is damaged or bent. The angle is not adjustable, damaged component(s) must be replaced to correct the steering axis inclination angle.
THRUST ANGLE is the angle of the rear axle relative to the centerline of the vehicle. Incorrect thrust angle can cause off-center steering and excessive tire wear. This angle is not adjustable, damaged component(s) must be replaced to correct the thrust angle.
Alignment Diagrams
Diagram from Jeep JL Wrangler Factory Service Manual.
How To Measure Caster In Jeep Jl Parts
Disclaimer: Utmost care should be taken when modifying anything to your suspension. Injury to you, your Jeep, and/or others can result from improper suspension modifications or alterations. The author is not a certified mechanic and assumes no responsibility for damage or injury.
Jeep Steering Alignment 101 – What do these terms mean?
Toe
Toe is the amount that the wheels are pointed in or out, often called 'total toe in or out'. On a Jeep CJ it is only adjustable on the front axle and is adjusted by rotating the long tie rod or in some cases rotating the threaded sleeve at the tie rod end. The short rod from the pitman arm is called the drag link. Adjusting the tie rod usually requires loosening the clamps that keep the tie rod secure and removing or un-attaching the steering stabilizer. Typically a Jeep's toe is adjusted 1/4″ less in the front of the tire to the rear of the tire.
See Adjusting Jeep CJ Toe
Caster
How To Measure Caster In Jeep Jlo
Alignment Definitions
The following are common wheel alignment definitions as defined by Jeep and that you will need to be familiar with:
CASTER is the forward or rearward tilt of the steering knuckle from vertical. Tilting the top of the knuckle rearward provides positive caster. Tilting the top of the knuckle forward provides negative caster. Caster is a directional stability angle. This angle enables the front wheels to return to a straight ahead position after turns.
CAMBER is the inward or outward tilt of the wheel relative to the center of the vehicle. Tilting the top of the wheel inward provides negative camber. Tilting the top of the wheel outward provides positive camber. Incorrect camber will cause wear on the inside or outside edge of the tire. The angle is not adjustable, damaged component(s) must be replaced to correct the camber angle.
WHEEL TOE POSITION is the difference between the leading inside edges and trailing inside edges of the front tires. Incorrect wheel toe position is the most common cause of unstable steering and uneven tire wear. The wheel toe position is the final front wheel alignment adjustment.
STEERING AXIS INCLINATION ANGLE is measured in degrees and is the angle that the steering knuckles are tilted. The inclination angle has a fixed relationship with the camber angle. It will not change except when a spindle or ball stud is damaged or bent. The angle is not adjustable, damaged component(s) must be replaced to correct the steering axis inclination angle.
THRUST ANGLE is the angle of the rear axle relative to the centerline of the vehicle. Incorrect thrust angle can cause off-center steering and excessive tire wear. This angle is not adjustable, damaged component(s) must be replaced to correct the thrust angle.
Alignment Diagrams
Diagram from Jeep JL Wrangler Factory Service Manual.
How To Measure Caster In Jeep Jl Parts
Disclaimer: Utmost care should be taken when modifying anything to your suspension. Injury to you, your Jeep, and/or others can result from improper suspension modifications or alterations. The author is not a certified mechanic and assumes no responsibility for damage or injury.
Jeep Steering Alignment 101 – What do these terms mean?
Toe
Toe is the amount that the wheels are pointed in or out, often called 'total toe in or out'. On a Jeep CJ it is only adjustable on the front axle and is adjusted by rotating the long tie rod or in some cases rotating the threaded sleeve at the tie rod end. The short rod from the pitman arm is called the drag link. Adjusting the tie rod usually requires loosening the clamps that keep the tie rod secure and removing or un-attaching the steering stabilizer. Typically a Jeep's toe is adjusted 1/4″ less in the front of the tire to the rear of the tire.
See Adjusting Jeep CJ Toe
Caster
Caster is somewhat difficult to comprehend and measure with home tools. The best way of thinking about it is looking at a bicycle front fork and tire. The forks arrive at the center hub at an angle. The positive caster allows the tire to return to center (the reason you can ride a bike with no hands). Another example of extreme negative caster is shopping cart front wheels, they will follow in any direction that it is being pushed. Most Jeeps were equipped with about 4 degrees positive caster with no adjustments. Adding lift kits can mess with the castor decreasing the angle sometimes to the point of becoming negative. This will cause the Jeep to wander about the road. An improper caster angle can make flat towing dangerous and coming out of sharp corners exciting due to the wheel not coming back to center.
See Adjusting Jeep CJ Caster
How To Measure Caster In Jeep Jl Wheels
Camber
Camber is measured from looking at the front of the vehicle and drawing a 90 degree to horizontal vertical line through the edge of the tire. If the top of the tire is in further than the bottom this is negative camber. If the top is out further than the bottom this is positive camber. Negative camber will help a vehicle during cornering due to tire roll over but will also increase tire wear on the inner section of the tire. A Jeep is best set at zero camber.
How To Measure Caster In Jeep Jl 4x4
See Adjusting Jeep CJ Camber
