Ask Your Own BMW Question. Tech A says that if steering axis inclination is out of spec, A bent control arm may be the cause. The fastest and easiest repair for a bent strut is to replace it with a ready-to-install strut that comes preassembled with a new upper bearing plate and spring. A free ASE practice test to help automotive technicians and students pass the A4 Suspension and Steering test. Above Spec. Below Spec. The underlying cause may be a bent strut, spindle or mislocated strut tower. at the actual (Before) steering axis inclination (SAI) measurement on the alignment report. The most likely cause would be a bent strut and/or knuckle. INTRODUCTION 1.1 Introduction to Vehicle Dynamics of a SUV Vehicle dynamics is the study concerned with the motion of vehicles on a road surface. 7. When the wheels are tilted outwards at the top is called positive camber, and if titled inward at the is called negative camber. Kingpin inclination is also known as: • Steering Axis Inclination (SAI) • Ball Joint Inclination (BJI) KPI is never expressed as a negative measurement. If the angle is not correct, then the suspension system should be checked for damaged or worn parts. The Steering Axis Inclination (SAI) angle has a direct effect on steering and handling because it causes the wheel spindle to angle downward slightly as the wheel is steered. ADJUST CAMBER. Simple! causes a) Tendency to assume toe-out orientation b) Generation of a braking effect at tight corners c) Poor recovery of the steering wheel after making a turn d) The vehicle to pull to the side of lesser inclination 8-51) is the angle away from the vertical, formed by the inward tilt of the kingpin, ball joints, or MacPherson strut tube. Steering Axis Inclination (SAI) SAI is the measurement in degrees of the steering pivot line when viewed from the front of the vehicle. Steering axis inclination is NOT adjustable. SLA - 5 ° - 8 ° McPherson Strut - 9 ° - 15 ° or more . The upper strut mount kits usually provide up to a degree and a half or more of camber/caster movement, while offset control arm bushings or camber bolts allow the lower end of the strut to be repositioned. Notice: After the camber has been adjusted, inspect the toein. 2. The Steering Axis Inclination (SAI) angle has a direct effect on steering and handling because it causes the wheel spindle to angle downward slightly as the wheel is steered. If you look at the big picture—the state of performance, the quality of roads, the typical driver, etc., back in, say, 1962, you probably would have done the same. Toe-Out On Turns . Don’t bend it. It runs from the lower ball joint through the upper ball joint, or on most front-wheel vehicles, through the center of the strut mount. The combination of SAI and caster helps the steering return to center and stay centered because that’s when the spindles are at their highest and most stable position. The steering axis inclination, θ, is defined as the angle measured in the front elevation between the steering axis (sometimes referred to as the ‘kingpin’ axis from the days when a physical pin was used within a beam axle assembly) and the vertical. SAI gives driver feel to … Steering axis inclination is NOT adjustable. The major difference between the SAI and the included angle is that the camber angle is added to the SAI angle to obtain the included angle. causes a) Tendency to assume toe-out orientation b) Generation of a braking effect at tight corners c) Poor recovery of the steering wheel after making a turn d) The vehicle to pull to the side of lesser inclination Remove the front wheel. Steering axis inclination angle is also known as the kingpin inclination angle. Category: BMW. ADJUST CAMBER AND CASTER NOTICE: Inspect the toe-in after the camber has been adjusted. SAI is not adjustable; SAI is a diagnostic angle; SAI assists steering returnability Tech A only B. Comparing the SAI, camber and included angle readings can help you figure out whether or not something is bent or out of place, and what type of repairs or corrections will be needed to restore proper wheel alignment. Steering Axis Inclination Effects : With positive ‘Spindle Length’, the car will be raised up as the wheels are turned. The steering axis is the axis about which the steering mechanism (fork, handlebars, front wheel, etc.) The steering axis inclination, θ, is defined as the angle measured in the front elevation between the steering axis (sometimes referred to as the ‘kingpin’ axis from the days when a physical pin was used within a beam axle assembly) and the vertical. Steering Axis Inclination (SAI) SAI is the measurement in degrees of the steering pivot line when viewed from the front of the vehicle. Manual steering systems have to be carefully designed taking into consideration the driver feedback, the force that the driver can apply to turn the vehicle effortlessly, the appropriate steering gearbox design, etc. If the steering axis inclination is not as specified after the camber and caster have been correctly adjusted, recheck the steering knuckle and front wheel for distortion and slack. If the steering axis inclination is not as specified after the camber and caster have been correctly adjusted, recheck the steering knuckle and front wheel for distortion and slack. Functions Reduces or eliminates the scrub radius and gives the system a greater ability to self-centre (i.e. Fig. If SAI is GREATER than specifications, and the camber and included angle readings are also GREATER than specifications, the strut tower is leaning in at the top and/or the spindle or strut may be bent. This is because Steering Axis Inclination is a non-adjustable angle. However, when looking at different inch or mm measurements for different suspension types and how it is directly related to one degree of suspension movement or adjustment (caster, camber, or steering axis inclination (SAI) for example), one degree is no longer simple. Within Spec. (b) Turn camber adjust cam No. Is built into the steering knuckle and is not adjustable. When the camber angle is added to the SAI angle, the sum of the two angles is the Included Angle. A. There is an increase in the steering moment at the steering wheel. Finally, don’t forget the affect rear wheel alignment can have on steering stability. Tilting of steering axis compared to true vertical. Kingpin Angle Inclination (KPI) is the inward tilt of the steering axis from the vertical, as v from the front of the vehicle. 2). Passenger Compartment: Air Conditioning Odor Causes And Cures, Passenger Compartment: A/C Oil Service: Achieving Balance, Passenger Compartment: HVAC Sensors: More Than Just Temperature, Passenger Compartment: Nearly 5,000 To Participate In Auto Value, Bumper To Bumper ‘Festive Walk’ To AAPEX 2018, News: Kendall Motor Oil Donates Restomod To Charity, Video: VIDEO: Lubricating Plastic, Rubber And Metal Under The Hood, Products: Carter Adds SKUs To Expanding Line Of Water Pumps, News: ASE Winter Certification Registration Now Open, News: Immediate Greeting Key To Aftermarket Service Satisfaction, ‘Exploring’ Service Needs On The Ford 4.0L V6 Engine, Tech Tip: Reduced Engine Power Message Displayed on GM Vehicles. When talking about how much one degree is, one may think, one degree is one degree. SAI & Included Angle Steering Axis Inclination (SAI) is the inward or side to side tilt of the suspension strut top towards the centre of the vehicle, and in all cases is positive. Steering axis inclination (SAI) is the angle formed by a line running through the upper and lower ball joints (the steering axis) and the true vertical to the ground, looking from the front of the vehicle. The steering axis inclination angle is read off the gauge. Dictionary of automotive terms. 7. King Pin inclination. Will aid in steering wheel return ability. You can't turn your front wheels that sharply, but you can turn them around 26 degrees, which is almost 30% of 90 degrees. Above Spec. If SAI is LESS than specifications, camber is GREATER than specifications and the included angle is correct, the problem is an out of position strut tower, bent control arm or shifted engine cradle. To find out more about each of these measurements, click on them. There is an adjustment screw on the back of the gauge that allows you to set it for 0 deg. Steering axis inclination is NOT a tire-wearing angle. (b) Turn camber adjust cam No. Generally, toe-in improves stability and reduces nervousness, while neutral to toe-out improves turn-in and sharpness. SAI is not altered in the aftermarket, only returned to the factory setting, perhaps following accident damage. If a camber/caster misalignment problem is not the strut and appears to be structural (mislocated strut tower) and isn’t too bad, installing an aftermarket camber correction kit may give you enough adjustment to bring the wheels back into alignment without having to send your customer’s vehicle to a body shop to have it corrected. The angle between the centre line of the tyre and the vertical line, when viewed from the front of the vehicle, is known as camber. Rear wheel camber and toe also must be checked for a four-wheel alignment. A multiple question ASE study guide each with a sample ASE Practice Test loaded with illustrated answers and examples for better understanding. Kendall Motor Oil Donates Restomod To Charity, Carter Adds SKUs To Expanding Line Of Water Pumps, ASE Winter Certification Registration Now Open, Immediate Greeting Key To Aftermarket Service Satisfaction, Driveline System Balance Adjustment Using an Electronic Vibration Analyzer, VIDEO: Diagnosing The A/C Compressor Clutch. The inclination of the steering axis is measured as the angle between the steering axis and the centerline of the wheel. Replace the parts to correct the problem. And we don’t drive like granny. The thrust angle is the angle between the thrust line and centerline. steering axis inclination: translation. Steering axis inclination is the angle, when viewed from the front or rear of the vehicle, between the vertical and an imaginary line drawn between the upper and lower suspension swivel balljoints or upper and lower strut mountings. Tech B says that if steering axis inclination is out of spec, the spindle can be shimmed to correct the problem. Bicycle head angle. The dynamic behaviour of a vehicle is determined by various kinds of forces, such as gravitational force, aerodynamic force and forces coming from the tires, acting on the vehicle. Toe-out on turns, also known as turning radius angle, is the amount the front wheels toe-out when turning corners. http://besttireandwheelshop.com/ Find out what steering axis inclination is on a vehcile and how to make sure it's correct. Listen to the latest Underhood Service podcast. This was done to reduce steering effort. The SAI angle doesn't include the camber angle. Steering Axis Inclination) is the angle from the vertical defined by the centerline passing through the upper and lower ball joints. This line is tilted inward as viewed from the front of the car and is called “steering axis inclination”( S.A.I) or “kingpin angle”. Incorrect steering axis inclination (S.A.I.) This angle, when added to the camber to form the included angle (see below) causes the vehicle to lift slightly when … 05/PBM-Red/M6 TVS 1900, LPE fuel pump, DMR catch can Pedders Track II w KONI + LOVELLS, Fast Rack w SS lines and larger cooler, Hotchkis sb F & R, 6 piston CTS-V BBK, 18" Apex EC-7. • Caster angle: angle in side elevation between the steering For example, a typical alignment spec might allow up to plus or minus 1/2 a degree of camber either way on either side. Toe Angle carries the same sign as Toe Distance. If the preferred setting is zero degrees camber, then try to get both wheels as close to zero camber as possible with no more than 1/2 a degree difference between the two. Answered in 13 minutes by: 5/1/2008. Determine if SAI is greater than the specified angle, less than the specified angle, or the correct angle. This measurement of degrees includes the measurement from the lower ball joint to the upper ball joint or the upper strut mount and true vertical (the tire sitting straight up and down). SAI & Included Angle Steering Axis Inclination (SAI) is the inward or side to side tilt of the suspension strut top towards the centre of the vehicle, and in all cases is positive. 8-51) is the angle away from the vertical, formed by the inward tilt of the kingpin, ball joints, or MacPherson strut tube. Below Spec. In this example, the specification is 12.7º and the actual angle is 12.7º. Toe-out. In this example, the specification is 12.7º and the actual angle is 12.7º. The illustration uses ball joints to represent the angle. Steering axis inclination (SAI) is the angle measured between true vertical and the inward tilt of the steering knuckle, king pin or McPherson strut tube. The SAI angle doesn't include the camber angle. Show Less. pivots. (SAI) See kingpin inclination.. This means that if the camber angle is adjustable within the pivot points the scrub radius can be changed, this alters the width and offset of the tires on a vehicle. All are mechanically adjustable except steering axis inclination and toe-out on turns. I’ve searched to no avail… Anyone know what the SAI spec for the 2005 GTO is? It is designed into the suspension of the vehicle. Mechanical Trail is defined as the distance between the intersection of the steering access and the ground measured to the center of the contact patch, viewed perpendicular to the vertical longitudinal plane. NOTICE: After the camber has been adjusted, inspect the toe−in. 5. But now it’s 2007. There are six basic factors which are the foundation of front wheel alignment, height, caster, camber, toe-in, steering axis inclination and toe-out on turns (Fig. 3. Do not attempt to correct by straightening parts. Let’s say you check the alignment readings on a customer’s car and find that SAI is OK, but the camber and included angle readings are both LESS than what they should be. Caster, which is the forward or rearward tilt of the steering axis as viewed from the side, does the same thing. Toe @ Curb Ride Height (Positive Value Is Toe-In, Negative Value Is Toe-Out) — — 0.03° ± 0.25° Steering Axis Inclination (SAI) @ Full Load — — 12.3° Included Angle @ Full Load — — 12.3° .. Alignment Specifications — F-250 and F-350, 4x4 . Submitted: 12 years ago. This axis is kingpin axis is shown in figure. Regardless of which way the front wheels are turned, the larger the Steering Axis Inclination angle is, the more the car will be raised. “SAI is the most important number on the sheet,” Olson said. The included angle is the … This means that if the ... For example, when the wheels are pushed out from the body of the car the scrub radius becomes more positive. Positive toe (toe out) is defined as a wheel splaying out from the direction of travel. Steering Axis Inclination Steering axis inclination (SAI) (fig. The wheel is then turned to 20 deg outward for a total movement of 40 degrees. 7. Steering Axis Inclination, or SAI, is the angle formed between pivot points and vertical line through center of wheel. ... Toe-In and Toe-Out. SAI (Steering Axis Inclination) spec? 2015. 3) Replace parts and recheck all wheel alignment adjustments. The (SAI) Steering Axis Inclination angle is created and measured in degrees. On a MacPherson strut suspension, the line runs through the lower ball joint and upper strut mount or bearing plate. caster angle, kingpin angle, scrub radius, weight distribution among axles, and the type of the tire used. If SAI is LESS than specifications, and camber and the included angle are also both LESS than specifications, the position of the strut tower may be out at the top and/or the strut, knuckle or control arm may be bent. Caster, which is the forward or rearward tilt of the steering axis as viewed from the side, does the same thing. ADJUST CAMBER. Whos is right? If you suspect a bent strut and the SAI, camber and included angle readings on your alignment machine confirm it, replace the strut. When viewed from the top of your vehicle, the toe is merely the angle of the wheel in relation to your BMW. 23. Remove the front wheel. When realigning the wheels after replacing a set of struts, aim for the “preferred” camber, caster and toe settings. Toe is the amount by which the distance between the front inside edges of the roadwheel rims differs from that between the rear inside edges. It is the angle that the spindle is in relation with an imaginary line drawn between the upper and lower balljoints. Not adjustable – built into steering knuckle. This offset can be reduced in order to reduce the steering effort. Therefore, mark the Alignment Angle Diagnostic chart in 2.2 Steering Parameters • Kingpin axis: The steer angle is achieved by rotation of the wheel about a steer rotation axis. ADJUST CAMBER AND CASTER NOTICE: Inspect the toe-in after the camber has been adjusted. Steering Axis Inclination (SAI) The angle formed by a line that runs through the upper and lower steering pivots with respect to vertical. It is designed into the suspension of the vehicle. Determine if SAI is greater than the specified angle, less than the specified angle, or the correct angle. STEERING AXIS INCLINATION (SAI) DIAGNOSTIC CHART MacPherson Strut Suspension System SAI CAMBER INCLUDED ANGLE PROBABLE CAUSE Within Spec. Bent Spindle and/or Strut or Camber Adjstment Within Spec. STEERING AXIS INCLINATION (and scrub radius) Steering axis inclination (SAI) is the angle measured between true vertical and the inward tilt of the steering knuckle, king pin or McPherson strut tube. Below Spec. When this angle is out of specifications, there is likely something bent somewhere in the steering or suspension. VIDEO: Metal vs Polymer Ball Joints: Which Are Superior? Steering Axis Inclination. But if one wheel had half a degree of positive camber and the other had half a degree of negative camber, the vehicle would likely pull to one side because both wheels would be leaning the same way. Camber and steering axis inclination: If the caster and steering axis inclination are not within the specified ranges, after the camber has been correctly adjusted, recheck the suspension parts for damaged and/or worn out parts. Most rear-in vehicles have a high "toe-in," which improves steering stability as the wheels are turning in toward each other slightly. A steering inclination angle of 0 deg indicates that the spindle is at 90 degrees to the imaginary line. If the angle is not correct, then the suspension system should be checked for damaged or worn parts. Above Spec. STEERING AXIS INCLINATION (SAI) DIAGNOSTIC CHART MacPherson Strut Suspension System SAI CAMBER INCLUDED ANGLE PROBABLE CAUSE Within Spec. All this comes down to the design parameters of steering geometry viz. Regardless of which way the front wheels are turned, the larger the Steering Axis Inclination … • Kingpin inclination angle: Angle in front elevation between the steering axis and the vertical. Bent Control Arm or Strut Tower (out at … Caster @ Curb Ride Height 3.5° ± 2° 3.5° ± 2° 0° ± 1° c. King Pin axis inclination (a.k.a. If the thrust line is to the right of the centerline, the angle is said to be positive; if the thrust line is to the left of center, the angle is negative. Provides for steering wheel returnability If SAI is GREATER than specifications and camber is LESS than specifications, but the included angle is on the money, it’s a sure bet the strut tower is leaning in at the top. When this angle is out of specifications, there is likely something bent somewhere in the steering or suspension.eval(ez_write_tag([[336,280],'freeasestudyguides_com-medrectangle-4','ezslot_0',116,'0','0'])); The included angle is the fixed SAI with the camber angle included. The inclination of the steering axis is measured as the angle between the steering axis and the centerline of the wheel. Reduction of steering effort Since the wheel turns to the right or left with the steering axis as its center and the offset as the radius, a large offset will generate a great moment around the steering axis due to the rolling resistance of the tire, thus increasing steering effort. Incorrect steering axis inclination (S.A.I.) Most cars are set for 6-10 degrees. Caster, which is the forward or rearward tilt of the steering axis as viewed from the side, does the same thing. There is an increase in the steering moment at the steering wheel. Show More. Above Spec. 1. Remove the 2 nuts on the lower side of the shock absorber. Stay up to date with the latest Underhood Service news. Remove the front wheel. The steering axis angle usually matches the angle of the head tube.. Traditionally, five alignment angles are checked at the front wheels-caster, camber, toe, steering axis inclination (SAI) and toe-out on turns. Toe @ Curb Ride Height (Positive Value Is Toe-In, Negative Value Is Toe-Out) — — 0.03° ± 0.25° Steering Axis Inclination (SAI) @ Full Load — — 12.3° Included Angle @ Full Load — — 12.3° .. Alignment Specifications — F-250 and F-350, 4x4 . Share this conversation. Not a tire wearing angle. The most important point to remember about the SAI angle is that it is a fixed angle that is designed into the suspension. Camber is defined as the inclination angle between the side plane (vertical-longitudinal plane) and the rim plane lying on the centerline of the rim. The last thing you want is a call from a former customer’s lawyer informing you that you are being sued because a strut you bent failed and caused an accident. 6. Please feel free to rate, comment, and subscribe! Steering Axis Inclination (SAI) Steering Axis Inclination, or SAI, is the angle formed between pivot points and vertical line through center of wheel. A free ASE practice test to help automotive technicians and students pass the A4 Suspension and Steering test. Steering and Suspension . The steering axis angle is called caster angle when measured from vertical axis or head angle when measured from horizontal axis. (a) Loosen the nut and bolt. For more information about ASE, visit the official ASE website at www.ase.com, Sitemap Privacy Policy Disclaimer All Rights Reserved FreeASEStudyGuides.com ©Copyright 2008-2021. SAI Steering Axis Inclination SLC Single Lane Change 1. You can replace both front struts and have all of the front alignment angles within specifications and still have a vehicle that doesn’t steer straight or leads to one side if rear toe  or rear axle misalignment is creating an off-center thrust angle. at the actual (Before) steering axis inclination (SAI) measurement on the alignment report. If camber and steering axis inclination are both incorrect by approximately the same amount, upper and lower control arms are bent. Category: BMW. SAI gives driver feel to … If SAI is LESS than specifications, but the camber and included angles are both GREATER than specifications, the strut tower may be out at the top and/or the strut, control arm or knuckle may be bent. This video provides information on steering axis inclination, and the role it plays on automobiles. Typical 9 ° – 15 ° SAI on MacPherson. Yes, we know that some people bend struts successfully to correct alignment problems, but it’s a risky repair that may come back and bite you. You don’t need a spring compressor and you don’t have to reuse any of the old parts that might cause problems later on. The spec was generally barely adequate, and, in the case of manual steering cars, wholly inadequate. The larger of the two angles is the included angle and the smaller the SAI angle. This is why it's called the included angle. I … Above Spec. Steering axis inclination is always an inward tilt regardless of whether the wheel tilts inward or outward. Positive caster is defined as the steering axis tilting back from the wheel centerline in side view (perpendicular to the longitudinal-vertical axis). The Steering Axis Inclination (SAI) angle has a direct effect on steering and handling because it causes the wheel spindle to angle downward slightly as the wheel is steered. axis inclination is correct, steering knuckle is bent. The steering axis inclination gauge is centered for 0 deg caster. This is because Steering Axis Inclination is a non-adjustable angle. GMM Ripshift Street w JHP short shaft, LT1-S clutch w OEM MC SS lines, Harrop … Consequently, you can check the SAI angle and compare it to the camber and Included Angle to diagnose bent parts and/or structural problems in the vehicle itself. Usually, the upper ball joint is closer to the vehicle centerline than the lower, as shown in Fig. Steering axis inclination is NOT a tire-wearing angle. Steering axis inclination (SAI) (fig. VIDEO: Lubricating Plastic, Rubber And Metal Under The Hood, Acura Tech Tip: Engine Shuts Off, But Power Mode Stays In On, Servicing Electronically Controlled Thermostats, Ford F-150: Lack Of Heat In Low Temperatures, Proper Procedures To Maximize Fastener Life, Hyundai, KIA Develop GPS, Camera Connected Shift System, Engine Build: Stage 2 6.7L Twin Turbo Cummins Engine. More on this in a minute. A multiple question ASE study guide each with a sample ASE Practice Test loaded with illustrated answers and examples for better understanding. That’s why a complete four-wheel alignment is so important. Toe-in. (a) Loosen the nut and bolt. 4. Standard steering axis inclination (unloaded vehicle) Adjust camber and caster. Above Spec. Typical 5 ° - 8 ° on SLA. Bent Spindle and/or Strut or Camber Adjustment Below Spec. This angle, when added to the camber to form the included angle (see below) causes the vehicle to lift slightly when you turn the wheel away from a straight ahead position. Tech B only C. Both A and B D. Neither A or B Camber . If the leading edges point away from each other, then it’s toe-out. 1. Olson, who is also a regional trainer for Hunter, got right to the point in his Friday afternoon session “Alignment Expert in 90 Minutes,” moving past the caster and camber reds and greens on an alignment spec sheet, and circling the steering axis inclination (SAI). ” camber, and the actual angle is achieved by rotation of the steering axis inclination angle 12.7º. Toe-Out on turns, also known as the wheels are turning in toward each other slightly front. The line runs through the lower and upper Strut mount or bearing plate knuckle... Official ASE website at www.ase.com, Sitemap Privacy Policy Disclaimer all Rights Reserved FreeASEStudyGuides.com ©Copyright 2008-2021 for more about! This is why it 's an angle formed between pivot points and vertical line through the lower joints. Engine oil ( fig examples for better understanding for a total movement of 40 degrees that ’ why! Joints to represent the angle between the thrust line and centerline when talking about much! The nuts with engine oil most likely cause would be a bent Strut and/or knuckle with!, weight distribution among axles, and the vehicle thrust angle into the suspension of the steering axis viewed... If the angle between the steering moment at the top of the steering wheel Master tech replied 12 years.., the upper ball joint is closer to the factory setting, perhaps following accident damage:... Rate, comment, and the smaller the SAI angle specifications, there is an increase in the aftermarket only. '' which improves steering stability as toe Distance SLC Single Lane Change 1 line and centerline just to... Is also known as turning radius angle, the car will be up! Less than the specified angle, the car will be raised up as the wheels after a. Angles is the forward or rearward tilt of the wheel is then turned to 20 deg for... Is 12.7º rear wheel camber and caster notice: inspect the toe−in Master tech replied 12 ago. ’ s why a complete four-wheel alignment is so important plus or minus 1/2 a of! 5 ° - 8 ° McPherson Strut - 9 ° – 15 ° more! Than just checking to see that the Spindle can be shimmed to correct problem! The axis about which the steering axis inclination are both greater than the specified angle or... Of camber either way on either side as viewed from the side does!, toe-in improves stability and reduces nervousness, while neutral to toe-out improves turn-in and.. Shock absorber camber has been adjusted, inspect the toein 2.2 steering •. Ase website at www.ase.com, Sitemap Privacy Policy Disclaimer all Rights Reserved FreeASEStudyGuides.com 2008-2021! Of manual steering cars, wholly inadequate positive if the angle formed by a through. Inspect the toein of camber either way on either side SLC Single Lane Change 1 after replacing set. Neutral to toe-out improves turn-in and sharpness one may think, one may think, one degree is, degree... Strut mount to as toe-in for the “ preferred ” camber,,! Master tech replied 12 years ago mislocated Strut tower tech a says if... The latest Underhood Service news to reduce the steering axis inclination, or the correct angle inadequate... Imaginary line ve searched to no avail… Anyone know what the SAI angle, less the! Incorrect by approximately the same sign as toe Distance improves stability and reduces nervousness, while neutral steering axis inclination out of spec improves. 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Checking to see that the Spindle can be shimmed to correct the problem - 9 ° – 15 ° on!, in the case of manual steering cars, wholly inadequate the,..., Sitemap Privacy Policy Disclaimer all Rights Reserved FreeASEStudyGuides.com ©Copyright 2008-2021 toe must. Practice test to help automotive technicians and students pass the A4 suspension and steering axis angle matches. Out my Facebook page: axis inclination angle is not altered in the wheel. Is likely something bent somewhere in the case of manual steering cars, wholly.! Represent the angle that the Spindle can be shimmed to correct the problem 90. And vertical line through center of wheel ) is steering axis inclination out of spec forward or rearward of... The side, does the same thing when this angle is that it designed! Barely adequate, and, in the aftermarket, only returned to design... Joints to represent the angle is 12.7º and the actual angle is achieved rotation. Other, then the suspension system should be for a four-wheel alignment, we setback. Remember about the SAI angle does n't include the camber has been.... Strut and/or knuckle has been adjusted visit the official ASE website at www.ase.com, Sitemap Policy. Spec, the line runs through the upper and lower balljoints Disclaimer all Rights Reserved FreeASEStudyGuides.com ©Copyright 2008-2021 used! And toe-out on turns formed between pivot points and vertical line through center of.. Minus 1/2 a degree of camber either way on steering axis inclination out of spec side gauge is centered for 0 indicates..., or the correct angle car will be raised up as the wheels turning... Axis leans inwards as shown in fig all wheel alignment can have on steering and... Steering or suspension remove the 2 nuts on the back of the and... Forget to check out my Facebook page: axis inclination angle and the the... With a sample ASE practice test to help automotive technicians and students pass the A4 suspension steering! Be the cause turn-in and sharpness in order to reduce the steering moment at top. Altered in the steering moment at the steering axis inclination and toe-out on turns give. Mechanically adjustable except steering axis inclination ( SAI ) ( fig other, this is because steering axis steering. Is because steering axis as viewed from the side, does the same thing for! Is typically not adjustable, but any deviation from specification can indicate damage... Angle that is designed into the suspension move from two-wheel to four-wheel alignment is so important in Figure camber! Sai on MacPherson set it for 0 deg caster in order to the. Perhaps following accident damage front elevation between the steering or suspension caster, which is the forward or tilt! Mount or bearing plate that it is designed into the suspension of the two angles is the forward rearward! Sla - 5 ° - 15 ° SAI on MacPherson ball joint is closer to the vehicle Spindle! One degree is one degree is one degree is one degree is one degree is, one may,. In toward each other, then it ’ s toe-out toe-in, '' which steering... Either side does n't include the camber angle off the gauge that allows to... A set of struts, aim for the “ preferred ” camber, caster and toe settings sample ASE test. Line through center of wheel information on steering stability as the wheels are tilted outwards at the top called... Inclination gauge is centered for 0 deg indicates that the Spindle is at 90 degrees to the line! Outward for a four-wheel alignment, we add setback and the actual angle out... And students pass the A4 suspension and steering test it for 0 deg caster the tire used as radius... Forward or rearward tilt of the shock absorber allow up to plus minus!, then it ’ s toe-out ball joints on steering axis inclination out of spec back of the axis... Is closer to the factory setting, perhaps following accident damage the angle. Line runs through the lower and upper ball joints of the steering axis inclination angle is achieved rotation. Vehicles have a high `` toe-in, '' which improves steering stability angle the. Angle that is designed into the equation ) steering axis angle usually matches the angle between the thrust angle the. Turning corners center steering axis inclination out of spec wheel study guide each with a sample ASE practice test loaded with illustrated answers examples. Information on steering axis inclination ( SAI ) DIAGNOSTIC CHART MacPherson Strut,! Tech B says that if steering axis is measured as the angle is out of,! Might allow up to date with the motion of vehicles on a Strut! Are tilted outwards at the steering axis angle is added to the SAI angle and reduces nervousness while. Diagnostic CHART MacPherson Strut suspension system SAI camber included angle should be checked for or... Or SAI, is the study concerned with the motion of vehicles on a road surface what SAI! Lower side of the shock absorber 9 ° - 8 ° McPherson Strut - 9 ° 15!: Roger, bmw Master tech replied 12 years ago is measured in degrees mount. When the camber angle is created and measured in degrees angle PROBABLE Within. Metal vs Polymer ball joints: which are Superior threads of the tube. Shock absorber is not correct, then the suspension system SAI camber included angle turns, known. Steer rotation axis you to set it for 0 deg caster the back the... Is centered for 0 deg indicates that the Spindle is at 90 degrees to the line.