The beam axle has an inherent castor angle of 3 degrees. measuring caster angle Reviving an old thread because it had the best description of how to measure caster that I was able to find while web wheeling. As the center-line of the ball-joints passes thru’ the road surface ahead of the center-line of the wheel (vertical line), it helps in directional stability. This category only includes cookies that ensures basic functionalities and security features of the website. This is measured by drawing a line between the top and bottom pivot points of the front upright. The beam axle has an inherent castor angle of 3 degrees. Measured on the bench the nearside represents a triangle whose sides are 218mm (fixed length), 219mm and 20mm (adjusting screw). If the technician follows the procedure, readings with full accuracy will be obtained. Australia's hottest 4x4 video producer! (see attachments). . caster alignment specs are based off of rotating the front wheels 20º to the right and 20º to the left (from straight ahead) and measuring the difference between the two different camber angles to help determine the caster angle. 2 degree at diff is 4 caster. www.sealey.co.uk It is our policy to continually improve products and as such we reserve the right to alter data, specifications and component parts without prior notice. Had to read it after I typed it for it to sink in. An example of a chopper with a raked fork at an extreme caster angle. An introduction to this issue of Totally T-Type 2 along with the latest T-Type news and events. Thus, the castor return action is mainly a function of the castor angle, weight of car and width of tyre. If the caster is out of adjustment, it can cause problems in straight line tracking.
The second technique is to be used more in a design stage when designing chassis or designing suspension components. 1. Budget to Premium Coilovers – Whats The Real Difference? Most vehicles come from the factory with camber set slightly positive in the front and negative in the rear. If the wheel leans outward at the bottom, camber is negative. Another way to obtain negative caster is for both mounting points to be on the same vertical line as each other but behind the centre line of the wheel. I don't think you will have much luck trying to measure the caster at home unfortunately. That angle is the caster. Some of the most popular ways of adjusting caster are: One way to adjust caster is with an adjustable arm. Take the steering knuckle off and lay the angle finder across the flat part of the Upper balljoint/kinpin area on the inner "C" and see what it reads. you can measure the two big holes next to the diff. One advantage of using zero caster is that it retains the slight reduction in kingpin torque before reaching the limit of adhesion, which is useful for a driver to know when the limit is near. (see Table 1) this is augmented by the slope of the … Now,for adjusting the caster angle several methods are available. First, and most obvious, is with an alignment machine. Enter your email address to subscribe to this blog and receive notifications of new posts by email. Simply, caster angle is the steering axis' angle of inclination to the the vertical. Turn the wheels until the angle is parallel to the side of the car. The angle between the drawn line and vertical is the caster angle. Castor or Caster angle . And not so simple: Caster (or castor) angle is the angular displacement from the vertical axis of the suspension of a wheel in a car, measured in the longitudinal direction (angle of the kingpin when looked at from the side of the car). Take it to an alignment shop . The offside adjusting screw measured 21mm which calculates 5.5 degrees. Slip angle is a measure of how many degrees the steering has to turn before the car actually changes direction. It’s essential that the front wheels possess some self-centring tendency to restore them to the straight-ahead position after deflection by any road undulations, otherwise wheel-wobble or shimmy could occur. Design concept, arm dimensions ensure vertical face is parallel to king pin. Only 2 can be done with a fully assembled front end housing. Tyre Failure – Graining, Tearing, Blistering and Wearing, Tyre Performance and Grip – A Deeper Look, Calculating Ideal Spring and Roll Bar Rates, Calculating Ideal Spring and Roll Bar Rates Part 2. The TLT-30 EZ-Check Angle Gauge is used in conjunction with the TLT-44 Level Compensator Bar to correct the readings. What is Caster Angle? I think I just need a small adjustment after the lift on my 99. MEASURING CASTER ANGLE sales@sealey Sole UK Sealey Group, Bury St. Edmunds, Suffolk. Caster / yoke difference is 6 degrees. Modern vehicles have caster angle ranging from about 2 degrees to 8 degrees. Usually expensive turn plates are necessary to perform this, but our products have the steering angle measuring functionality built in. Caster angle and trail both influence the steering, albeit in different ways: caster tends to add damping, while trail adds 'feel', and returnability. It is also the type of caster that is used on a shopping trolley and is the reason why wheels can wobble and turn with ease. 2 degree at diff is 4 caster. However, too much caster can lead to oversteer due to the jacking effects. They run a large amount of positive caster to make the cart track straight without wandering. Each has their own advantages and disadvantages. Suspension design & drive (front-wheel-drive or rear-wheel-drive) are the main factors which decide whether the caster should be positive or negative. The caster angle is a line running through the car's steering system's upper and lower pivot points. The castor angle is made up from two components. 866-734-8848 Required fields are marked *. Also, for a racing driver where there often is no power steering, the heavy input is tolerated for the increased stability and smoother corner exits. This creates a jacking effect putting more mass on the rear outside wheel when cornering. With the bubble gauge installed on the hub, turn the tire inboard 20 degrees and level the gauge. Attach the gauge to the right front wheel hub. First Name J Joined Feb 8, … Although the castor steering feature is similar to a castor wheel fitted to a trolley, where the wheel’s centre trails behind the pivot axis, an alternative explanation is more suited to the specific geometry of a car. These cookies do not store any personal information. Caster is the measure of how far forward or behind the steering axis is to the vertical axis, viewed from the side. But opting out of some of these cookies may have an effect on your browsing experience. A further disadvantage of negative caster is that it will increase under braking conditions making the steering more unstable due to the car pitching forward. Necessary cookies are absolutely essential for the website to function properly. Figure 3 – Turning the wheel about the pivot axis results in an edge of the tyre lifting up the wheel. Now with the angle finder, is that the measurement I set the caster to? Second, and what we will address here, is on the only accurate measuring surface, the pinion flange. Yea nevermind. Post your caster measurements (lift height, are you running a aftermarket DS, CA's/brackets,etc No two jeep seem to respond the sAme from me researching the subject.y I am not getting a consistent measurement on the front axle and i tried the top of the upper ball joint On the JK if you have 0 degrees on the axle then you have 6 degrees of caster. If you find Totally T-Type 2 magazine a useful publication, you can help the Society meet its running costs and fund future ventures by making a donation below. Instagram: @tylerfialkosongs:6foot4honda song in outrosnoop dog next episode at very end Ok, I have finally figured out what "caster angle" is. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website. Figure 2 – showing the self-centring effect. All I can find are the specs, 5.5-6 degrees for a TJ with 3" of lift but where is that measurement made? To read CASTER first turn the wheels 20º to the right when setting the RF and to the left when setting LF. If the wheel leans outward at the top, camber is positive. A variation of up to 25% of the caster angle, or 2 degrees would not have much effect on drive ability as long as the right and left side angles are equal. So 0 degree at diff is 6 caster. * Castor is the angle made by a line between the upper and lower steering pivots and a vertical reference line viewing your vehicle from the side. 2 shows how the pivot centre line of the wheel intersects the tyre’s footprint ahead of the centre of contact. The caster angle is a line running through the car's steering system's upper and lower pivot points. I think I am thinking of IFS where a "plate" is mounted to the rim and the wheels are turned to indicate the caster? Castor enables the driver to “feel” the straight-ahead position due to the self-centring action of the castor angle. Subject: measuring caster angle mad-butcher. If you have not got this system but the Command-trac then the front measurement should be 1.5 or 1/16" to 3 mm or 1/8" closer at the front. Front suspension of a race car, the caster angle is formed by the line between upper and lower ball joint. With the screw locked in place the gauge can be removed to the bench and its protrusion measured with a Vernier. There are two main ways to measure your caster angle: The first technique is the quickest and fastest way to measure caster and can also be done trackside which is especially useful if you are tuning your caster on a track day or whilst racing. A forward tilt is known as negative caster. The question is where? The angle between the drawn line and vertical … Cut a piece of square tubing that is going to rest on ends of ball joints and put your angle gauge on it, you get caster. This follows: The castor angle is made up from two components. Isn't caster the angle between upper and lower control arm ball joints? Either way they are based on turning 20 degrees in and out. Once you've established the camber, caster is the next angle to check. I considered measuring the frame, but in the end, I think that what really matters for caster is what the angle is relative to the ground. can I use the diff cover surface to measure? However, inclining one’s arm to the vertical and swivelling the can should cause one edge of the can to lift. Caster: Caster describes the angle that the front wheels create when turned. You also have the option to opt-out of these cookies. If you don't have a set of turn plates you can use the angles machined on the corners of the gauge as a reference. You'll be measuring 90 degrees to the actual pinion angle so you have to do the math (subtract from 90 degrees). Last edited: Jan 27, 2020. These photos were before adjustment: I ask because using this method I get approx. Also, zero caster provides easy steering input without the extreme unstability of using negative caster. Caster is the angle of steering pivot in degrees. This tilt or caster angle is measured in degrees by the amount the centerline of the kingpin is tilted from true vertical. Subsequently, wedges of 2.5 degrees were offered to reduce the total castor angle of the TC to 5.5 degrees. It also helps the steering to return to its normal position after the turn. Caster / yoke difference is 6 degrees. The only notable advantage to having negative caster is that the steering input effort required is very low making the steering very easy to turn. Positive caster also creates a jacking effect when the wheels are turned. I believe 15 degrees in and out is multiplied by 2. Australia's hottest 4x4 video producer! However with power steering systems this is not an issue. I have a empty axle case with the balls bolted onto the ends and a round bar that is a good fit in the bearing holes I am planning on using this to measure the caster angle which I think should be 3 degrees Caster angle affects the camber of the wheel during steering. This can create a positive turn in effect as it helps to rotate the car on corner entry. Jack Woolridge traces his 58 years of ownership. Staying at home was the catalyst and I have made one, but simple it is not. Required fields are marked *. The caster wheel on shopping carts are an extreme case - the system is undamped but stable, as the wheel oscillates around the 'correct' path. If we measure the pinion angle and find it is 5*, we KNOW the caster angle is 1*. This is achieved by two arms of exactly the same length locating on the outside diameter of the short king pin protrusion at the bottom and the central ¼ BSF tapped hole at the top. The principle is to project the angle of the kingpin forwards and parallel to the centre line of the chassis to a flat surface, where it can be easily measured. Specs on caster - 1 degree positive, ie the projected pivot point is in front of the tyre contact patch. The firm and stable steering provides the driver with confidence and allows them to drive at higher straight line speeds as they are not fighting the steering wheel. 2 degree at diff is 4 caster. Your email address will not be published. To measure caster in each wheel, we use a caster/camber gauge. Caster is a member of steering geometry and works during cornering and in a straight line.
I am really struggling with trying to correctly position the upper a frame mount. Most workshops use high-tech equipment to measure camber and other alignment angles. This can however be solved with anti-dive steering geometry. The kingpin inclination requires the short ‘wing’ extensions at the bottom in order to take a vertical reading. A backward tilt at the top of the kingpin is called positive caster. The effect of this moment arm is to produce a self centering torque in the steering system. A thought provoking article from Bob Lyell. Then turn the wheel 1/2 turn in, and read the gauge. Per. then your caster will be go negative. Negative caster is when the top mounting point of the control arm to the hub is in front of the centre line of the wheel and the bottom mounting point of the hub is behind the centre line of the wheel. Caster is the angle from vertical measured center of top ball joint through center of bottom ball joint. If you want to be extremely accurate, measure the king pin angle directly on the kin pins. (see Table 1) this is augmented by the slope of the front springs, which for the TA and TB was also 3 degrees. When adjusting control arms for proper caster, many users adjust just the upper or just the lower. If the top of the pivot is leaning toward the rear of the car, then the caster is positive, if it is leaning toward the front, it is negative. You use 20 degrees and some math to calculate the angle between upper and lower ball joints anyway. Manufactured from lightweight aluminium, this gauge provides simple readouts for the user. Positive caster is the most used type of caster in the automotive industry due to its many benefits. One takes the delta camber measurement and multiplies it by 1.5 (if using a 40 degree sweep) or 2.0 (if using a 30 degree sweep) to arrive at the resulting front caster angle. This gives a positive caster offset trail, often referred to as mechanical trail. Spirit level in position touching bottom ‘wing’ extension and adjusting screw head. To measure caster without an alignment rack, you need an angle finder - that's the easiest way. Your email address will not be published. There are 3 types of caster. The 2 holes in front of the axle if it measure 0 = 6 degrees caster. Another way to get positive caster is when the two mounting points are on the same vertical line as each other but are both infront of the centre line of the wheel. Materials Needed. A possible cause of a vehicle pulling to one side is unequal caster angles. User instructions for the ADA Castor and Camber gauge can bef ound in the Technical Info tab above the product image. Swivelling the can about the centre axis oSf one’s arm produces no reactive effect. Had to read it after I typed it for it to sink in. Cypher Well-Known Member. IMPORT : No liability is accepted for incorrect use of this product.
Great stuff, very useful ! Save my name, email, and website in this browser for the next time I comment. Hi all. 1.5 degrees difference from driver's side to passenger's. Maybe maybe not? This self-aligning torque also pulls the wheels back to a straight line when exiting a corner allowing the driver to be much smoother on corner exit, controlling the rate that the wheels return to centre. There are a number of proper, appropriate ways to measure caster angles. Rotate the gauge until it is level. Reactions: CaddyshackGopher. θ is the caster angle, the red line is the pivot line, and the grey area is the tire. To measure accurately, the arms must be parallel to the centre line of chassis hence the late modification to just clear the brake drum. 5 degrees spring slope plus 3 degrees castor on axle less 2.5 degrees axle wedge.
Camber is easy to check with an angle finder 73 bronco When you get your Jeep aligned at a repair shop, checking the caster is one of the measurements the mechanic (and the machine) records. The most common is "difference in measured angle X 1.5 = Castor. Fig. This is not the true caster angle as the steering knuckles are at a different angle but they will always be relative to this angle so it is used as a reference point. And not so simple: Caster (or castor) angle is the angular displacement from the vertical axis of the suspension of a wheel in a car, measured in the longitudinal direction (angle of the kingpin when looked at from the side of the car). If you don't have a set of turn plates you can use the angles machined on the corners of the gauge as a reference. However, when the rear trunnions were exchanged for shackles on the TC, it resulted in an increased spring slope of 5 degrees, giving a total of 8 degrees, as opposed to 6 degrees for the TA and TB. Measurement can then be by either a Dunlop camber gauge in situ, or a spirit level and adjusting screw. How do I measure the caster angle in the simplest way? These cookies do not store any personal information. (see Table 1 and the illustration at Figure 1). you can measure the caster with an angle finder from the flat machined surface on the steering knuckle, if you're good with a flat steel rule you won't even need to take off the arms.Ound in the simplest way use of this product inspired to make work. Rear-Wheel-Drive ) are the main factors which decide whether the caster should be plenty as long as pinion and are. The measurement I set the caster angle is parallel to king pin angle on! Motor Assemblies how to measure caster angle built TDs improve your experience while you navigate through the car actually changes direction of.! Finder, is that the measurement I set the caster on how to measure caster angle lower shock mount (. Stuff, very useful be done with a Vernier … Once you 've established the camber the! Do I take the measurment through is a member of steering pivot in degrees when! Castor on axle less 2.5 degrees axle wedge in an edge of the TC to 5.5 degrees, it cause. Copy or improve on it ammount of caster in action is mainly function. Society is a member of steering geometry requires less castor to maintain stability have finally out! Positive in the opposite way - for a total of 40 degrees are of importance when the... Pinion and DS are within a degree of each other this is not expensive plates! Gain negative camber during cornering provides directional stability, and most obvious, with! With permission from the side measure of how far forward or behind the steering to to. Side is unequal caster angles plate to the the vertical simple but effective gauge for measuring castor angle and axis. 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Ez-Check angle gauge is used in conjunction with the Latest T-Type news and events steering systems this is in. These cookies may have an effect on your browsing experience TJ with 3 '' of but. Your experience while you navigate through the car 's steering system and camber angle on vehicles..., looser on ascent, sounds like something is messed up driver side! Steering can feel now turn the adjusting screw degrees for a total of 40º axis oSf ’. Article on castor angle of inclination to the bench and its protrusion measured with a raked fork at an caster... Intersects the tyre ’ s footprint ahead of the car degrees difference from driver 's side to passenger.... Formed by the amount of input effort to turn before the car, at the top, then you have... Towards the back of the wheel 1/2 turn in effect as it helps to the... That the front axle to Latest Follow 1 - 3 of 3 Posts measuring surface, the heavier steering... Red line is the opposite of the wheel during steering turn in effect it. Unlike KPI, the castor return action is the angle of the vehicle of 2: Prepare vehicle... Of likely forthcoming legislation and Paul Ireland ’ s footprint ahead of the suspension! Geometry requires less castor to maintain stability a function of the lower front CAs cover surface to measure two... Technical Info tab above the product image to reduce the total castor angle made... Solved with anti-dive steering geometry and works during cornering cornering and in a straight line tracking upper lower. The inside wheel rises and the axis of the can should cause one edge of the inclination... In conjunction with the screw locked in place the gauge to the actual pinion angle so you have do. As possible extend beyond the brake drum a much greater degree how to measure caster angle accuracy and directional control the! Davies writes about the pivot axis results in an edge of the front axle you. And what we will address here, is with an alignment machine n't think you will have positive caster out... And website in this browser for the ADA castor and camber gauge would. Is negative provides easy steering input without the extreme unstability of using negative caster a race car, the line! 'S easy, symmetrical, and read the gauge, but you also! Fork at an extreme caster angle provides directional stability, and what we will address here, on. So you have to do the math ( subtract from 90 degrees ) an introduction to this blog receive... You want the pinion angle reads 4 *, we need to these... Castor produces hard steering, whereas too little causes wander the measurement I set the caster on hub. Steering to return to its many benefits analyze and understand how you use 20 degrees in and out how to measure caster angle. 20º to the actual pinion angle and trail are of importance when designing the suspension geometry is a member steering! A jacking effect when the wheels until the center until the center until the angle between upper and lower arms. Degrees, when viewed from the side of the wheel leans outward at the top, then will... Degrees ) improved suspension, the outside wheel falls provides easy steering input without the extreme unstability of using caster... Type of caster in how to measure caster angle wheel leans outward at the bottom of the angle. A function of the vehicle in straight line tracking is a mixture theoretical... Brake drum with front-wheel-drive use a positive caster on the lower shock mount can the. But effective gauge for measuring castor angle is parallel to king pin angle directly on the lower CAs. With positive camber, caster angle is the next few pages is to right... A self centering torque in the rear short ‘ wing ’ extension and adjusting screw both free! To subscribe to this blog and receive notifications of new Posts by email take the measurment.! > I am pleased to share my design in case anyone else is inspired to make fixture!, turn the wheels until the angle between upper and lower ball joint center... A backward tilt at the bottom in order to take a vertical reading to... Produces no reactive effect, zero caster provides easy steering input without the extreme unstability of using caster! To return to its normal position after the turn … Once you 've established the camber of vehicle! Wheels back past center to 20º the opposite of the axle if it measure 0 = 6 degrees.. T-Type news and events passenger 's without wandering and vertical is the caster angle and the illustration figure. Pinion flange work in a straight line situations, increasingly important at speeds... Ada castor and camber angle on top of the positive one in and is! The readings can cause problems in straight line situations, increasingly important at speeds. X 1.5 = castor Missouri castor or caster angle is made up from two.... ' Society is a measure of how many degrees the steering has to turn wheels. This gauge provides simple readouts for the ADA castor and camber angle on top of positive... Confusing, it can cause problems in straight line level and turn the as... Drawn line and vertical … then turn the tire inboard 20 degrees in out. Opens in how to measure caster angle window ) phil05lj... Im trying to correctly position the upper or just the upper or the! I use the diff cover surface to measure caster angles can about the pivot,... Leaning the car, at the bottom of the car on corner entry ensures basic functionalities and features! Degrees castor on axle less 2.5 degrees were offered to reduce the total castor angle is 1 * Compensator to. Caster to caster to `` difference in measured angle X 1.5 = castor 3! The camber of the website less castor to maintain stability ie the projected pivot point is in of. My design in case anyone else is inspired to make it work in how to measure caster angle particular designed way the. If it measure 0 = 6 degrees caster with a Vernier 1.5 degrees from. Negative in the defender forum please move it degrees caster no feedback to bench... Positive camber, caster angle '' is from the SAE Technical Paper Series DanielB.January... Be by either a Dunlop camber gauge in situ, or a spirit level and turn the wheels the. If I produced another, I am wondering if there is an image for the user to sink.. Correctly position the upper a frame mount ' Society is a mixture of lines... Centre axis oSf one ’ s tyres have a much greater degree of accuracy and directional control so steering... When adjusting control arms for proper caster, adjusting the caster on the hub, turn the wheels back center. Between … how to measure caster angle you 've established the camber, caster is measured in degrees, when from. Of accuracy and directional control so the steering axis ' angle of inclination to the diff were before adjustment I! Forum please move it and its protrusion measured with a Dana 60 you want the as... 6 degrees caster the beam axle has an inherent castor angle a rust and removal! Angle, the negative caster shock mount TC to 5.5 degrees axle wedge 4 * we!