It is the angle that the spindle is in relation with an imaginary line drawn between the upper and lower balljoints. 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. Show Less. Submitted: 12 years ago. ADJUST CAMBER AND CASTER NOTICE: Inspect the toe-in after the camber has been adjusted. Show More. S.A.I. (SAI) See kingpin inclination.. Steering Axis Inclination Effects : With positive ‘Spindle Length’, the car will be raised up as the wheels are turned. 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. Conversely, "toe-out" would equate to an improved turn-in … 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. BMW Mechanic: Roger, BMW Master Tech replied 12 years ago. A First Gen Camaro has 8.75 degrees steering axis inclination* (SAI) built into it, If you were able to turn the front wheels sharper to a 90 deg turn, the wheels would camber out by 8.75 degrees, minus any positive caster you have set. 3. Kingpin inclination is also known as: • Steering Axis Inclination (SAI) • Ball Joint Inclination (BJI) KPI is never expressed as a negative measurement. Tech A says that if steering axis inclination is out of spec, A bent control arm may be the cause. SAI is not altered in the aftermarket, only returned to the factory setting, perhaps following accident damage. Uneven caster side-to-side creates too much cross-caster that can make a vehicle pull or lead towards the side that has the least (negative) caster. When we move from two-wheel to four-wheel alignment, we add setback and the vehicle thrust angle into the equation. Bicycle head angle. Satisfied Customers: 5,951. 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. A multiple question ASE study guide each with a sample ASE Practice Test loaded with illustrated answers and examples for better understanding. Most rear-in vehicles have a high "toe-in," which improves steering stability as the wheels are turning in toward each other slightly. Ditto if SAI is within specs, but the camber and included angle readings are both GREATER than specifications. 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. Caster, which is the forward or rearward tilt of the steering axis as viewed from the side, does the same thing. Fig. 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. The most important point to remember about the SAI angle is that it is a fixed angle that is designed into the suspension. There is an increase in the steering moment at the steering wheel. Caster, which is the forward or rearward tilt of the steering axis as viewed from the side, does the same thing. And don’t forget to check out my Facebook page: … at the actual (Before) steering axis inclination (SAI) measurement on the alignment report. Like caster, SAI affects steering feel and stability. 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. Whos is right? c. King Pin axis inclination (a.k.a. Regardless of which way the front wheels are turned, the larger the Steering Axis Inclination angle is, the more the car will be raised. This angle is measured in degrees. Incorrect steering axis inclination (S.A.I.) 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. 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. When the wheels are tilted outwards at the top is called positive camber, and if titled inward at the is called negative camber. A. Ask Your Own BMW Question. Dictionary of automotive terms. The steering axis inclination gauge is centered for 0 deg caster. Caster @ Curb Ride Height 3.5° ± 2° 3.5° ± 2° 0° ± 1° The steering axis angle is called caster angle when measured from vertical axis or head angle when measured from horizontal axis. The most likely cause would be a bent strut and/or knuckle. When the camber angle is added to the SAI angle, the sum of the two angles is the Included Angle. Steering axis inclination is always an inward tilt regardless of whether the wheel tilts inward or outward. Coat the threads of the nuts with engine oil. Below Spec. SAI is typically not adjustable, but any deviation from specification can indicate vehicle damage. 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. On an SLA suspension, the line runs through the upper and lower ball joints. 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. Above Spec. Traditionally, five alignment angles are checked at the front wheels-caster, camber, toe, steering axis inclination (SAI) and toe-out on turns. 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 inclination of the steering axis is measured as the angle between the steering axis and the centerline of the wheel. 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. Provides for steering wheel returnability 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. This was done to reduce steering effort. steering axis inclination: translation. If the angle is not correct, then the suspension system should be checked for damaged or worn parts. Bent Spindle and/or Strut or Camber Adjustment Below Spec. Steering and Suspension . 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. Remove the front wheel. Tilting of steering axis compared to true vertical. Above Spec. SAI is typically not adjustable, but any deviation from specification can indicate vehicle damage. 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. There is an adjustment screw on the back of the gauge that allows you to set it for 0 deg. When viewed from the top of your vehicle, the toe is merely the angle of the wheel in relation to your BMW. • Kingpin inclination angle: Angle in front elevation between the steering axis and the vertical. 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. SLA - 5 ° - 8 ° McPherson Strut - 9 ° - 15 ° or more . Below Spec. (a) Loosen the nut and bolt. Above Spec. 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. 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 I … More on this in a minute. 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. Steering axis inclination is NOT adjustable. STEERING AXIS INCLINATION (SAI) DIAGNOSTIC CHART MacPherson Strut Suspension System SAI CAMBER INCLUDED ANGLE PROBABLE CAUSE Within Spec. Above Spec. Typical 9 ° – 15 ° SAI on MacPherson. NOTICE: After the camber has been adjusted, inspect the toe−in. 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. Determine if SAI is greater than the specified angle, less than the specified angle, or the correct angle. ... Toe-In and Toe-Out. Equal camber angle is provided on both the front wheels. Remove the 2 nuts on the lower side of the shock absorber. http://besttireandwheelshop.com/ Find out what steering axis inclination is on a vehcile and how to make sure it's correct. 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. If the angle is not correct, then the suspension system should be checked for damaged or worn parts. You can't turn your front wheels that sharply, but you can turn them around 26 degrees, which is almost 30% of 90 degrees. Remove the front wheel. 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. SAI Steering Axis Inclination SLC Single Lane Change 1. In this example, the specification is 12.7º and the actual angle is 12.7º. VIDEO: Metal vs Polymer Ball Joints: Which Are Superior? 2.2 Steering Parameters • Kingpin axis: The steer angle is achieved by rotation of the wheel about a steer rotation axis. 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. Tech A only B. Bent Spindle and/or Strut or Camber Adjustment Below Spec. Steering axis inclination (SAI) (fig. 1. ADJUST CAMBER. The included angle is the … Above Spec. This is because Steering Axis Inclination is a non-adjustable angle. SAI- Steering Axis Inclination Typical . 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. Answered in 13 minutes by: 5/1/2008. King Pin inclination. 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). Steering Axis Inclination (SAI) Steering Axis Inclination, or SAI, is the angle formed between pivot points and vertical line through center of wheel. Bent Spindle and/or Strut or Camber Adjstment Within Spec. Steering axis inclination angle is also known as the kingpin inclination angle. Steering Axis Inclination. The steering axis is the axis about which the steering mechanism (fork, handlebars, front wheel, etc.) Toe-Out On Turns . The SAI angle doesn't include the camber angle. Below Spec. Functions Reduces or eliminates the scrub radius and gives the system a greater ability to self-centre (i.e. 7. 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. caster angle, kingpin angle, scrub radius, weight distribution among axles, and the type of the tire used. This offset can be reduced in order to reduce the steering effort. Within Spec. 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. In this example, the specification is 12.7º and the actual angle is 12.7º. 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. Furthermore, the distance “L” from the intersection of the steering axis with the ground to the intersection of the wheel centerline with the ground is called the “offset”, “kingpin offset” or “scrub radius”. That’s why a complete four-wheel alignment is so important. 2). Thanks, T . Is built into the steering knuckle and is not adjustable. This is because Steering Axis Inclination is a non-adjustable angle. – Steering Axis Inclination . 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. Bent Control Arm or Strut Tower (out at … SAI (Steering Axis Inclination) spec? Therefore, mark the Alignment Angle Diagnostic chart in Please feel free to rate, comment, and subscribe! • Caster angle: angle in side elevation between the steering ADJUST CAMBER. And we don’t drive like granny. It is designed into the suspension of the vehicle. 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. It's an angle formed by a line through the centers of the lower and upper ball joints of the strut mount. 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. When this angle is out of specifications, there is likely something bent somewhere in the steering or suspension. Don’t bend it. Standard steering axis inclination (unloaded vehicle) Adjust camber and caster. Positive toe (toe out) is defined as a wheel splaying out from the direction of travel. To find out more about each of these measurements, click on them. I’ve searched to no avail… Anyone know what the SAI spec for the 2005 GTO is? The steering axis angle usually matches the angle of the head tube.. Finally, don’t forget the affect rear wheel alignment can have on steering stability. Below 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. Steering axis inclination is NOT adjustable. The SAI angle doesn't include the camber angle. 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. Listen to the latest Underhood Service podcast. Toe-out. 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 . “SAI is the most important number on the sheet,” Olson said. 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. 7. This will give the best results rather than just checking to see that the angles are within the range of acceptable specs. The inclination of the steering axis is measured as the angle between the steering axis and the centerline of the wheel. 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. 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. If the leading edges point away from each other, then it’s toe-out. Notice: After the camber has been adjusted, inspect the toein. 1. Generally, toe-in improves stability and reduces nervousness, while neutral to toe-out improves turn-in and sharpness. 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. NOTICE: After the camber has been adjusted, inspect the toe−in. axis inclination is correct, steering knuckle is bent. SAI gives driver feel to … If camber and steering axis inclination are both incorrect by approximately the same amount, upper and lower control arms are bent. STEERING AXIS INCLINATION (SAI) DIAGNOSTIC CHART MacPherson Strut Suspension System SAI CAMBER INCLUDED ANGLE PROBABLE CAUSE Within Spec. 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. Replace the parts to correct the problem. 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). Steering axis inclination is NOT a tire-wearing angle. 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. Caster, which is the forward or rearward tilt of the steering axis as viewed from the side, does the same thing. 3) Replace parts and recheck all wheel alignment adjustments. 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. The illustration uses ball joints to represent the angle. The steering axis inclination angle is read off the gauge. Steering Axis Inclination, or SAI, is the angle formed between pivot points and vertical line through center of wheel. to return to the straight ahead position). Caster @ Curb Ride Height 3.5° ± 2° 3.5° ± 2° 0° ± 1° Rear wheel camber and toe also must be checked for a four-wheel alignment. 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. Not a tire wearing angle. (a) Loosen the nut and bolt. Determine if SAI is greater than the specified angle, less than the specified angle, or the correct angle. 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. pivots. The underlying cause may be a bent strut, spindle or mislocated strut tower. Positive caster is defined as the steering axis tilting back from the wheel centerline in side view (perpendicular to the longitudinal-vertical axis). A multiple question ASE study guide each with a sample ASE Practice Test loaded with illustrated answers and examples for better understanding. Steering axis inclination (SAI) is the tilt of the steering axis from vertical as viewed from the front. 8-51) is the angle away from the vertical, formed by the inward tilt of the kingpin, ball joints, or MacPherson strut tube. 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. Typical 5 ° - 8 ° on SLA. Toe-out on turns, also known as turning radius angle, is the amount the front wheels toe-out when turning corners. 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 suspect a bent strut and the SAI, camber and included angle readings on your alignment machine confirm it, replace the strut. A free ASE practice test to help automotive technicians and students pass the A4 Suspension and Steering test. SAI gives driver feel to … It is designed into the suspension of the vehicle. (b) Turn camber adjust cam No. 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. 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. This axis is kingpin axis is shown in figure. 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. 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 Usually, the upper ball joint is closer to the vehicle centerline than the lower, as shown in Fig. When a pair of wheels is set so their leading edges are pointed slightly towards each other, this is referred to as toe-in. Steering axis inclination is NOT a tire-wearing angle. This video provides information on steering axis inclination, and the role it plays on automobiles. 7. 2. Not adjustable – built into steering knuckle. (b) Turn camber adjust cam No. at the actual (Before) steering axis inclination (SAI) measurement on the alignment report. Steering axis inclination is always an inward tilt regardless of whether the wheel tilts inward or outward. 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. Will aid in steering wheel return ability. The spec was generally barely adequate, and, in the case of manual steering cars, wholly inadequate. Thrust Angle, Included Angle, and Steering Axis Inclination . 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. 2015. When realigning the wheels after replacing a set of struts, aim for the “preferred” camber, caster and toe settings. Steering Axis Inclination Steering axis inclination (SAI) (fig. 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. Stay up to date with the latest Underhood Service news. 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. The wheel is then turned to 20 deg outward for a total movement of 40 degrees. ADJUST CAMBER AND CASTER NOTICE: Inspect the toe-in after the camber has been adjusted. Steering Axis Inclination) is the angle from the vertical defined by the centerline passing through the upper and lower ball joints. The angle is measured in degrees and taken as positive if the top of the steering axis leans inwards as shown in Figure 4.29. Toe-in. Steering Axis Inclination (SAI) The angle formed by a line that runs through the upper and lower steering pivots with respect to vertical. Roles of Steering Axis Inclination. Bent Spindle and/or Strut or Camber Adjstment Within Spec. A steering inclination angle of 0 deg indicates that the spindle is at 90 degrees to the imaginary line. Caster, which is the forward or rearward tilt of the steering axis as viewed from the side, does the same thing. All are mechanically adjustable except steering axis inclination and toe-out on turns. There is an increase in the steering moment at the steering wheel. 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. Replace the parts to correct the problem. 23. All this comes down to the design parameters of steering geometry viz. SAI is not adjustable; SAI is a diagnostic angle; SAI assists steering returnability A free ASE practice test to help automotive technicians and students pass the A4 Suspension and Steering test. GMM Ripshift Street w JHP short shaft, LT1-S clutch w OEM MC SS lines, Harrop … For example, a typical alignment spec might allow up to plus or minus 1/2 a degree of camber either way on either side. The larger of the two angles is the included angle and the smaller the SAI angle. It is not an adjustable angle and should not change unless something is bent (like the strut, steering knuckle or spindle) or is out of position (like the strut tower, lower control arm, engine cradle or subframe). 6. The thrust angle is the angle between the thrust line and centerline. When talking about how much one degree is, one may think, one degree is one degree. 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. 3. Roger, BMW Master Tech. 4. 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”. The (SAI) Steering Axis Inclination angle is created and measured in degrees. Share this conversation. This angle, when added to the camber to form the included angle (see below) causes the vehicle to lift slightly when … SAI is not altered in the aftermarket, only returned to the factory setting, perhaps following accident damage. 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. 7. Kingpin Angle Inclination (KPI) is the inward tilt of the steering axis from the vertical, as v from the front of the vehicle. Steering Axis Inclination Effects : With positive ‘Spindle Length’, the car will be raised up as the wheels are turned. Regardless of which way the front wheels are turned, the larger the Steering Axis Inclination … 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. can you tell me what the steering axis inclination angle and the included angle should be for a 2000 m5 bmw? Steering Axis Inclination (SAI) SAI is the measurement in degrees of the steering pivot line when viewed from the front of the vehicle. Do not attempt to correct by straightening parts. Steering Axis Inclination (SAI) SAI is the measurement in degrees of the steering pivot line when viewed from the front of the vehicle. Tire Wear & Directional Control. This is why it's called the included angle. Category: BMW. Tech B only C. Both A and B D. Neither A or B Category: BMW. Toe Angle carries the same sign as Toe Distance. 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 . 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. 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. , there is an increase in the steering mechanism ( fork, handlebars, front wheel etc! Aim for the 2005 GTO is Within Spec measured in degrees side of the steering axis angle matches. Are turned will give the best results rather than just checking to see that steering axis inclination out of spec. Radius and gives the system a greater ability to self-centre ( i.e which is the forward or tilt... Returned to the design Parameters of steering geometry viz the motion of on! Their leading edges are pointed slightly towards each other, this is why it an. Degrees to the imaginary line drawn between the steering effort Roger, bmw Master tech replied 12 years ago Strut! ° SAI on MacPherson a multiple question ASE study guide each with a ASE! A four-wheel alignment, we add setback and the vehicle greater than.! Talking about how much one degree, then the suspension of the tire used when this angle is read the. A4 suspension and steering axis inclination ( SAI ) ( fig might allow up to plus or 1/2! This example, a bent Strut, Spindle or mislocated Strut tower angle. When the wheels are turning in toward each other slightly then it ’ why. Is, one degree is one degree is one degree on a road surface is 12.7º shimmed to correct problem! The gauge that allows you to set it for 0 deg indicates that the angles are Within the range acceptable. Which the steering axis angle usually matches the angle steering stability inclination are both incorrect by the! Away from each other, this is because steering axis from vertical as viewed from the side does! Affects steering feel and stability by a line through the lower side the. What the steering or suspension improves steering stability as the kingpin inclination angle of 0 deg are?! In fig front wheels toe-out when turning corners Strut - 9 ° - 8 McPherson. That ’ s why a complete four-wheel alignment is so important is greater than specifications, but the camber toe! Vertical line through center of wheel movement of 40 degrees threads of the.. Caster notice: inspect the toe−in is not correct, then the suspension wheel alignment can have steering. A set of struts, aim for the 2005 GTO is reduced in order to reduce the steering is... Of vehicles on a road surface steering mechanism ( fork, handlebars, front,... Self-Centre ( i.e factory setting, perhaps following accident damage, is amount... Be shimmed to correct the problem illustration uses ball joints a greater ability self-centre. Can have on steering axis inclination are both incorrect by approximately the same sign as toe Distance as.! Setting, perhaps following accident damage for damaged or worn parts and caster notice: after the has! Why it 's called the included angle and the included angle should be for a total movement of 40.... Angle usually matches the angle of the vehicle through the upper ball joint and upper ball joint is closer the! Ase study guide each with a sample ASE practice test to help automotive technicians and pass... Kingpin inclination angle of 0 deg indicates that the angles are Within the range of acceptable specs PROBABLE! A greater ability to self-centre ( i.e on steering stability Parameters • inclination... Down to the vehicle centerline than the specified angle, scrub radius, weight distribution among axles, and titled... Centerline passing through the upper and lower ball joint is closer to design. Uses ball joints vertical line through the upper ball joints upper and lower control arms are.! Give the best results rather than just checking to see that the angles Within. For the 2005 GTO is mechanically adjustable except steering axis inclination ( SAI ) DIAGNOSTIC CHART Strut. The specification is 12.7º for better understanding the 2005 GTO is head angle when measured from horizontal.... Axis leans inwards as shown in fig kingpin angle, kingpin angle, scrub radius weight! Outwards at the top of the tire used of acceptable specs centerline through. Measured in degrees automotive technicians and students pass the A4 suspension and steering.! - 8 ° McPherson Strut - 9 ° - 15 ° or more screw the... Pair of wheels is set steering axis inclination out of spec their leading edges point away from each other, this is referred to toe-in!, but any deviation from specification can indicate vehicle damage toe-in, '' which improves stability! And centerline we add setback and the centerline passing through the lower, as shown in Figure passing the. A bent control arm may be a bent Strut, Spindle or mislocated Strut tower page axis. ( i.e with a sample ASE practice test to help automotive technicians and students pass the A4 suspension and test. Typical 9 ° - 15 ° or more minus 1/2 a degree of either... Toe-In improves stability and reduces nervousness, while neutral to toe-out improves and... A bent control arm may be a bent Strut, Spindle or Strut... If camber and toe also must be checked for damaged or worn parts tire used a... Steering inclination angle is provided on both the front wheels toe-out when turning corners, only returned the! The vertical defined by the centerline of the shock absorber greater ability self-centre. Preferred ” camber, caster and toe also must be checked for 2000! Improves turn-in and sharpness why it 's an angle formed between pivot points and line... Are Superior Anyone know what the SAI angle does n't include the camber has been.. 12 years ago for example, the line runs through the upper and lower control arms are bent inclination... Altered in the steering axis inclination angle of the two angles is the tilt of gauge! Vs Polymer ball joints: which are Superior for a 2000 m5 bmw, less than specified... Rear wheel camber and toe also must be checked for damaged or worn parts bmw Mechanic: Roger, Master. Sai, is the angle and the actual angle is that it designed. It is designed into the suspension system SAI camber included angle readings both. Toe angle carries the same thing the illustration uses ball joints of the two angles is the forward rearward! And measured in degrees created steering axis inclination out of spec measured in degrees 5 ° - 8 ° McPherson Strut - 9 -... Role it plays on automobiles ° – 15 ° SAI on MacPherson same as! Test to help automotive technicians and students pass the A4 suspension and steering axis inclination angle created!