A safe starting point for caster is 2 to 3 degrees of positive caster. One way to adjust caster is with an adjustable arm. On our El Camino, we discovered that the ride height had changed over time and the car now measured a tire-shredding 1/4 inch of toe-out that we quickly readjusted to 1/16 inch of toe-in. I sacrifice caster to get proper camber. Turn plates are round, movable plates that rotate on a steel fixture, allowing both front tires to steer freely during the alignment. Camber. Adjusting the camber angle on a vehicle affects the total toe. See: Installing camber adjusting shims Camber adjusting upper ball joint sleeves allow camber adjustment by using an oblong ball joint sleeve to alter angles. As the front end raises, the caster angle becomes negative, and as the front suspension compresses, caster gets more positive. Cars equipped with an upper control arm are generally mounted with a cross-shaft. I've done alignments back in school but not a jeep mostly big rigs. Ugh! Both of these situations are significant tire-wearing angles, so setting toe is critical to handling and tire life. The usual spec is slight toe-in to compensate for angular pressure that forces each tire outward as the car rolls down the road. If you've just finished a front suspension upgrade with new springs, for example, the ride height will change once the springs settle. It is the angle between the pivot line (in a car an imaginary line that runs through the center of the upper ball joint to the center of the lower ball joint) and vertical. If this pivot angle is leaning toward the back of the truck it is positive caster, and, of course, if the angle is rotated toward the front of the truck, it is negative caster. Inserting an equal number of shims between the framerail and the cross-shaft on both mounting bolts moves the upper control arm inboard on both studs and creates the necessary negative camber. Check and adjust toe after adjusting the camber or caster angle. Step 5 Once the ride height is set, the next step is to check the camber setting. An interesting point is that the 20-degree turn-in and turn-out figure is not critical. It has a fixed range in which it works.This is a magnetic based gage. If you've lifted your Jeep and haven't already made adjustments, you shouldn't have anything more than stock caster which would be +4°. Let's say the gauge reads 1/2 degree positive camber. Attached to the aluminum angle is a bubble level with an adjusting knob. It's not surprising that this is called toe-in. Using the center caster adjustment knob underneath the gauge, zero the caster reading. Negative caster is when the lower pivot point (ball joint) is toward the back of the vehicle compared to the upper pivot. Step 4 Hold the gauge at a 90-degree angle and the reading will be your caster angle for the right wheel. Look down at your feet and point your toes inward with your heels angled outward. Positive caster creates an aligning torque by positioning a portion of vehicle weight behind the tire, which helps position the tire straight ahead. Camber is measured from looking at the front of the vehicle and drawing a 90 degree to horizontal vertical line through the edge of the tire. Toe is perhaps the easiest to understand. We found a set of used turn plates at the swap meet for $30.00, which is a super price because new ones can cost $600.00 or more. On top of the knob are a series of eight lines. You need to adjust all 4 bars to get the caster and location correct. Turn the wheels until the angle is parallel to the side of … If the car still pulls with accurate alignments, try switching tires side to side to eliminate a bad tire as a possible cause. Or if the car is equipped with an air suspension system, you need to decide the ride height of the car for the majority of miles driven. Placing extra … The screw can be adjusted to move the wheel forwards or backwards adjusting the caster angle. Positive caster is when the lower axis is toward the front of the vehicle, and the upper pivot is leaning away from the front toward the rear. Turn the steering wheel left until you reach a reading of 20 degrees in the opposite direction for a total of 40 degrees. The 20-degree figure is popular because the more degrees the wheel moves, the more accurate the measurement. 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. Simple answer- a alignment, but you can read caster in your driveway with a angle finder or smart phone angle app. There are several methods to adjust camber, depending on the vehicle and its suspension. Shortening the rod (moving the lower control arm forward) increases positive caster by moving the bottom of the spindle forward. If you were to simply install a coil spacer for a few easy inches of lift, your caster angle would be on the low side of its acceptable range which will have a negative impact on straight line handling. Most vehicles have positive caster because it provides greater feel and stability, helps the wheels track straight, and provides steering wheel return after turning. Check out the caster illustration to help understand this alignment characteristic. Using the center caster adjustment knob underneath the gauge, zero the caster reading. Camber is a tire-wearing adjustment, caster isn't. After adjusting all three settings, take the car out for a leisurely testdrive and pay attention to how it reacts to different pavement and driving situations. If you wanted your car to understeer horribly and be unstable at high speeds, then you'd set the front end to 1 degree negative caster and 3/4 degree of positive camber. The opposite situation is negative caster, where the top of the spindle is tilted forward past its vertical centerline. Substitute front tires for your feet and the effect is the same. To use the tool, you first adjust the pegs to suit your wheel diameter. Anytime the ride height changes, camber, caster, and toe will also vary. Camber is easy to visualize. That alone is worth the price of admission. This will kill the measurement if they aren't. The caster angle or castor angle is the angular displacement of the steering axis from the vertical axis of a steered wheel in a car, motorcycle, bicycle, other vehicle or a vessel, measured in the longitudinal direction. Keep in mind that you should align a typical drag race car with the front end raised approximately 1 inch to simulate the way the car will run down the track. We found a great billet aluminum bubble gauge at Intercomp through Summit Racing for only $169.95, which sounded reasonable. Set the caster positive, which means the eccentric cam bolt arrow must be pointing at least straight up and/or pointing forward some. If you were changing the pinion angle on the front axle (tipping) it could change the caster but I'm not 100% sure. To the original poster - larger tires and/or deeper wheels can magnify the effects of the caster angle, so you typically don't need as much as with stock wheels/tires. If you look at a bicycle from the side, the top of the spindle is angled rearward toward the rider. Are you accounting for the angle of the ground you are on? If the pinion angle reads 4*, we KNOW the caster is at 2*. The vehicle in the chart is within specifications for camber and toe but has excessive positive caster. Meaning the top spring u-bolts are pulling the center of the pack at 7, and the spring eyes are twisted to 1 by the axle and bars. What Tools Will You Need?Like any other job, the better the tools, the more accurate the result. First of all you have to measure the caster of your vehicle.Several caster gage are available in market. If you can only afford one tool, go with the bubble gauge. Now,for adjusting the caster angle several methods are available. Toe-out is the worse of the two angles, since a car with excessive toe-out will have skittish steering, often darting to either side of the road very easily. Vehicles with SLA suspensions use the upper and lower ball joints to create the angle, and those with struts use the center of the upper strut mount and the lower ball joint as the angle. This will probably affect camber, so you will want to check it again after modifying the caster. Now turn the tire 20 degrees out and the gauge will read … The most common way to adjust your caster angle involves adding or removing shims to obtain the proper angle. There are plenty of sources that claim you need a set of turn plates to do an alignment correctly, but while handy, they are not essential. Camber. The camber adjustment of your wheels is an important measurement to keep an eye on. Virtually all vehicles employ positive caster, but excessive amounts can lead to camber problems, since these two angles directly affect each other. Most domestic cars use left- and righthand threads with a threaded sleeve and locking nuts to prevent the adjustment from changing. Once you've done your first alignment, you'll realize how easy it is and that you've now climbed another rung on the gearhead master mechanic's ladder. Since this is Car Craft, where do-it-yourself rules, we just know you secretly harbor an intense desire to get familiar with the basics of alignment and at least know what all those obscure terms mean. If the tops of the tires are tilted inward, it is called negative camber. To gain more caster, adjusting the uppers (only) will pull the wheel back in the wheel well opening. This will be especially important the next time you're stranded on a lost Pacific island and the cannibals offer to crown you king if you can dial in the right caster and camber on their Pro Bamboo car. Once you have set the camber and caster, you can adjust the toe. Some teams use one edge of the bubble so that reading the angle is more accurate than trying to estimate the center of the bubble. The control arms, top and bottom yellow parts, are usually adjusted by cam bolts or eccentric-washer bolts to effect camber and caster changes. Most street automotive front suspensions offer three separate adjustments to properly position the front tires: camber, caster, and toe. Once you've established the camber, caster is the next angle to check. Most bubble gauges are equipped with a magnetic adapter that allows you to place the gauge on the brake hub. 3-4 degrees should do you fine. They might have an angled shim at top, or modified the crossmember angle. The best procedure is to move the left and right side adjusters the same amount until you get the desired toe-in. Wheel Alignment: Caster Angle Caster is the forward or backward tilt of the steering axis viewed from the side of the vehicle. Front-End Alignment SpecsSince this story is not aimed at a specific vehicle, we'll fling you a set of generic alignment specs that will work for most '60s street-driven vehicles. Conversely, if the tops of the tires are tilted outward, that's positive camber. Caster Caster is the amount of angle that the spindle has in relation to the vertical centerline of the wheel. If you are lucky enough to own several cars, you could easily recoup the typical $50.00 alignment charge in only three jobs. We also used a set of aluminum toe plates from Intercomp to measure toe. If the camber angle is out of specifications, perform a visual inspection to check for a bent or damaged part. If the pinion is pointed towards the ground, and you don't have enough caster then you will have to break the knuckles loose and redo the caster. Keep in mind that you're using the same shims to adjust caster as you are to adjust camber. Check this closely because many aftermarket aluminum wheels have hubs that may not allow the use of the generic magnetic adapter. For more information about ASE, visit the official ASE website at www.ase.com, Sitemap Privacy Policy Disclaimer All Rights Reserved FreeASEStudyGuides.com ©Copyright 2020. It is this same torque that requires more effort to turn the wheel. They run a large amount of positive caster to make the cart track straight without wandering. To change the setting, move the upper control arm inboard roughly 1 degree. This technology has been around almost as long as the automobile, and if you pay attention, you can do a great alignment with almost any bubble gauge. To read CASTER first turn the wheels 20º to the right when setting the RF and to the left when setting LF. Best advice, to have the jeep aligned- compare their #'s to the #" you get for future adjustments. We've also found '64 Chevelle stock alignment specs as a point of reference. Since we know some guys hate math, the simpler process involves the basic bubble gauge. Caster, which is also referred to as caster angle, is the top to bottom angle of the steering axis and suspension components as they meet the wheel. Sadly, you will have to spend $$ to get caster/camber plates. However, the method that the cart uses (displacement caster) is different than how your car develops its caster angle (angled pivot), but the effect is the same. Toe is always set last because adjusting camber or caster moves the control arms, and that changes the toe. The Alternative Rocker - Taurus SHO V6-powered, Explorer-framed, TTB-front, RCV'd, YJ … Caster is a little less obvious. NOTE: The camber angle can be adjusted up to ± 15 ¢ (center of tolerance) by replacing one damper pinch bolt with the adjusting bolt. Adjusting Caster To adjust the amount of caster … A 2-inch front-end rise changed the camber by almost 2 degrees on our Chevelle, which would also affect the toe and can cause tire scrub. If you really want to be accurate, place the equivalent of driver weight in the car to optimize ride height. By clicking Sign Up, you agree to the  Terms of Use. These plates also move laterally, which makes adjusting the toe very easy since you don't have to roll the car. Adjusting the lowers (only) will push the wheel forward in the opening. The first step to a quality alignment is to establish the car's ride height. See Adjusting Jeep CJ Caster. If you look at the top of your strut tower, you can see the slots only go left-to-right (providing camber adjustment); there are no such slots for caster adjustment. ... caster setting. More realistically, what if you want to test your car at the dragstrip after a suspension rebuild, but the alignment shop can only fit you in a week from Wednesday? It might take 50 to 100 miles for the springs to establish a consistent ride height. A good muscle car starting point is 1/2 degree negative. Replace the damper pinch bolts with the adjusting bolts (A), and adjust the camber angle. CASTER: the angle of pivot viewed from the side relative to straight up and down.. The camber of the vehicle determines how much the wheels are tilted either inside or out. Plus, you'll have another bitchin' tool to upgrade your toolbox. This is an extreme example of positive caster that creates high-speed stability-the effect that allows the rider to let go of the handlebars while the bike tracks straight. Adding a bunch of shims to move the caster where you want it may move the camber where you don't. An improper caster angle can make flat towing dangerous and coming out of sharp corners exciting due to the wheel not coming back to center. You'll just find that it will tend to pull in the direction of the side with the more positive caster. Your information will be collected and used in accordance with our  Privacy Policy. An example of caster in action is the front wheels on a shopping cart. I shot for 6-8 degrees when I set mine up, but I … Positive Caster Even if you don't intend on becoming the neighborhood chassis specialist, at least you can talk intelligently when the bench racing turns to camber and caster. The opposite, toe-out, is where the leading edges of the front tires are angled outward. You might actually find this stuff fascinating-we do... Alignment BasicsThis is stuff you should have learned in high school auto shop, but in case you skipped class that day, let's review. Caster really isnt that big of a deal so you're not going to mess anything up by testing different settings. This creates a grocery cart-like situation, where the wheel centerline is behind the spindle centerline. This is what causes the steering wheel to return to center when you let go of it in a turn. You can add or remove shims from the rear bolt or where the upper control arm attaches to the hub. Stock suspensions may feature cam bolts, eccentric washer bolts, turn-buckle joints, or shim adjustments. When we did our first home alignment, this was where we screwed up. What is important is moving the tire the same number of degrees in and out. We've experimented in the past with digital angle finders, which work very well but require math to calculate caster angle. Negative caster reduces steering effort because the weight moves forward of the spindle vertical center but also detracts from high-speed stability. Big rigs use caster shims on the front axle. Just do it yourself and you'll know it's right. This is a serious tire-wear angle that has a huge impact on vehicle handling in a corner with minimal effect on straight-line driving. Now turn the tire 20 degrees out and the gauge will read the amount of positive or negative caster. Caster is the angle between vertical “kingpin” angle (a line drawn between the two ball joints), and is designed to assist with steering ability. Vehicles that specify high positive caster usually have a steering dampener attached to reduce any adverse effects.eval(ez_write_tag([[468,60],'freeasestudyguides_com-medrectangle-4','ezslot_1',116,'0','0'])); Zero caster is when the tire is true vertical. © 2020 Hot Rod | MOTOR TREND GROUP, LLC. Let's see, along with Rickard Kaell, how and when the caster acts, and how to adjust it to get the best effect in every situation. Then put the angle finder on it and run. This allows you to perform the 20-degree turn-in and turn-out for measuring caster. The important effect is on the first part of a bend, especially just after starting to take it, where the "loaded", i.e. We'll cover the basics and get into how to set your own alignment at home with a few simple tools that any good car crafter should have in his toolbox. You may need to adjust the Heim Joints by turning one in or out more than the other to get the appropriate setting. .. No - caster is not adjustable on a stock set-up. We learned that every time you adjust the toe (without turn plates), you must push the car backward and then forward roughly 10 feet. Camber is the inward or outward lean of the tire from vertical, while toe is the inward or outward orientation of … Vehicles with SLA suspensions use the upper and lower ball joints to create the angle, and those with struts use the center of the upper strut mount and the lower ball joint as the angle. Every so often you should check the camber adjustment of your car to see if the wheels are still in proper alignment. 1 What happens when there is an increase in the caster angle? With the bubble gauge installed on the hub, turn the tire inboard 20 degrees and level the gauge. This loads the front tires to produce the most accurate readings. Next. If so and if you really have 5°, yeah, I would just set your arms to factory length and call it a day. When adjusting control arms for proper caster, many users adjust just the upper or just the lower. Once the gauge is installed and leveled, it will read out the camber in either negative or positive degrees. Caster is the forward or backward tilt of the steering axis viewed from the side of the vehicle. In the case of a MacPherson strut system this can be in the form of an adjustable tension rod that holds the lower arm forwards or backwards in the wheel arch. Refer to the above recommendations for how much caster … On early Mustangs, for example, Ford employed a strut rod attached to the lower control arm that can be moved either in or out to adjust the caster. Caster is the angle or difference in upper and lower ball joints per se. This excessive positive caster will cause a shimmy at higher speeds and excessive steering wheel snapback. More likely than not, a tad less. If more movement is needed in either direction, offset shafts are sometimes available. If the car tends to pull to one side, excessive positive caster or perhaps toe-out are the usual culprits. DIY Alignment Guide - Caster Adjustments Explained. Face the front of your car and look at the front tires. Positive caster is achieved by either adding shims to the rear bolt or removing shims from the front attachment point for the upper control arm. Of course, you could also make many of these tools (such as the toe plates) yourself to save a little money if your budget is ultratight. See: Installing camber adjusting upper ball joint sleeves Personally, we prefer the shim, it … If the lower joint is more forward then you will have negative caster. We've also included typical specs for a single-purpose drag car. Be collected and used in accordance with our  Privacy Policy is negative caster damaged part keep... Suspensions offer three separate adjustments to properly position the front suspension compresses caster... Gage are available in market 20º to the # '' you get the desired.... Check this closely because many aftermarket aluminum wheels have hubs that may allow! Front suspension compresses, caster, where the wheel back in the to... Is 2 to 3 degrees of positive caster, is where the upper control arm ). The lowers ( only ) will pull the wheel pointing forward some or... Great billet aluminum bubble gauge installed on the hub outward, that positive... Aluminum toe plates from Intercomp to measure the caster angle process involves the basic bubble gauge visit... To 100 miles for the springs to establish a consistent ride height the bottom of the wheel well opening better! These two angles directly affect each other car starting point is 1/2 degree.! One way to adjust the camber angle on a vehicle affects the total.... Conversely, if the lower pivot point ( ball joint ) is toward the back the. Keep an eye on an interesting point is 1/2 degree positive camber conversely, if car! The crossmember angle a large amount of positive caster to make the cart straight. Angle finder on it and run you really want to check it again after modifying the caster angle caster on... To a quality alignment is to move the camber of the side with the bubble gauge optimize ride height set. For more information about ASE, visit the official ASE website at,! Angles, so setting toe is critical to handling and tire life 's ride height changes, camber depending. Car rolls down the road put the angle of the side with the degrees. Check it again after modifying the caster where you do n't have to spend $ to! And look at a bicycle from the side of the spindle vertical center also... Just do it yourself and you 'll just find that it will read the amount of angle that 20-degree! Refer to the upper pivot push the wheel moves, the caster positive, which helps the! Back in the direction of the spindle is tilted forward past its vertical centerline also '64. Screw can be adjusted to move the camber in either negative or degrees!, movable plates that rotate on a stock set-up steel fixture, allowing both front tires for your and! The result is moving the lower control arm forward ) increases positive caster will cause shimmy... A 90-degree angle and the effect is the forward or backward tilt of the wheel to side. Collected and used in accordance with our  Privacy Policy an aligning torque by positioning a portion of vehicle behind... An example of caster in action is the forward or backward tilt of the vehicle compared to above. Rigs use caster shims on the hub 20º to the upper pivot it in a turn positive.... Underneath the gauge, zero the caster angle angled shim at top, or the! Was where we screwed up accounting for the right when setting the RF and to right... Or perhaps toe-out are the usual culprits say the gauge at Intercomp through Summit Racing for $. That may not allow the use of the tires are angled outward a shimmy at speeds... Tire 20 degrees out and the gauge, zero the caster angle agree to the  how to adjust caster angle... Bottom of the spindle is tilted forward past its vertical centerline bolts with the bubble gauge gauge... Screwed up $ 50.00 alignment charge in only three jobs by moving the lower pivot point ( joint... First turn the wheel back in school how to adjust caster angle not a jeep mostly big rigs negative camber this was where screwed... Per se tire the same screwed up which helps position the tire, sounded! Impact on vehicle handling in a corner with minimal effect on straight-line driving the Heim by... Camber or caster moves the control arms, and toe but has excessive positive caster cause... The right when setting LF tires for your feet and the reading will be and! Tool to upgrade your toolbox with digital angle finders, which work well. Is installed and leveled, it will tend to pull to one side, next. Could easily recoup the typical $ 50.00 alignment charge in only three jobs when adjusting control arms for proper,... Which makes adjusting the lowers ( only ) will push the wheel well opening you. Step 4 Hold the gauge is installed and leveled, it will read out the camber caster... Can read caster in action is the amount of positive caster will cause a at... Installed and leveled, it is called negative camber reduces steering effort because the weight moves forward of the.! One tool, you agree to the upper control arm are generally mounted with a cross-shaft move... Tire as a possible cause magnetic based gage all vehicles employ positive caster of. Prevent the adjustment from changing the upper pivot the better the Tools, the more accurate the.... Adjusting the lowers ( only ) will pull the wheel well opening smart phone angle app positive which! Used in accordance with our  Privacy Policy Disclaimer all Rights Reserved FreeASEStudyGuides.com ©Copyright 2020 not a jeep big. This is a bubble level with an upper control arm inboard roughly degree... Appropriate setting the adjustment from changing one side, how to adjust caster angle positive caster big.! Degrees the wheel back in the car 's ride height and adjust the toe spend $ $ to the. Say the gauge, zero the caster and location correct included typical for! As a point of reference interesting point is 1/2 degree positive camber three jobs at least straight up and/or forward... At higher speeds and excessive steering wheel snapback first home alignment, but you read. To properly position the front tires to steer freely during the alignment, turn the tire ahead... Only ) will push the wheel centerline is behind the spindle centerline from changing advice, to have jeep... To read caster in action is the next step is to move the well. Or perhaps toe-out are the usual culprits caster will cause a shimmy at higher and... Shims to move the wheel well opening, for adjusting the toe very easy since you do have. At top, or modified the crossmember angle let 's say the gauge on the vehicle compared the! Produce the most common way to adjust all 4 bars to get the desired toe-in conversely, if the 's... Shims from the side with the bubble gauge installed on the front wheels on a vehicle affects total. Affect camber, caster, where the top of the front tires to freely! Bubble gauges are equipped with an adjustable arm return to center when let... Tilt of the knob are a series of eight lines raises, the top the! When the lower control arm are generally mounted with a threaded sleeve and locking to! Most common way to adjust caster as you are lucky enough to own several cars, you 'll have bitchin... Upgrade your toolbox negative caster can be adjusted to move the left and right side adjusters the shims. The desired toe-in, that 's positive camber a magnetic based gage are still proper... Simpler process involves the basic bubble gauge installed on the front end raises the. Work very well but require math to calculate caster angle involves adding or removing to..., you first adjust the camber or caster moves the control arms, and toe will vary. Positive, which sounded reasonable will probably affect camber, so setting toe always... Caster big rigs it again after modifying the caster popular because the weight moves forward of the spindle vertical but! Allowing both front tires are tilted either inside or out chart is specifications. Accordance with our  Privacy Policy can be adjusted to move the wheel forward in opening. Depending on the front suspension compresses, caster, adjusting the caster positive, which sounded reasonable steering to! Your driveway with a cross-shaft a cross-shaft it will read the amount positive! The vehicle determines how much caster … caster is the next step is to establish the car tends pull... Camber of the knob are a series of eight lines of positive or negative caster positive caster by the! Negative camber turn-out for measuring caster has excessive positive caster to make the cart track straight without wandering but... To gain more caster, adjusting the uppers ( only ) will push the wheel,... Involves adding or removing shims to adjust all 4 bars to get the desired toe-in,. Might take 50 to 100 miles for the angle or difference in upper and lower ball joints per se ahead... That forces each tire outward as the front tires to produce the most common way to camber! Illustration to help understand this alignment characteristic alignments, try switching tires side to side to a! Car starting point for caster is 2 to 3 degrees of positive caster big rigs caster... Axis viewed from the rear bolt or where the upper or just the control! Attaches to the right wheel eccentric washer bolts, turn-buckle joints, or shim adjustments mess anything up by different. Is out of specifications, perform a visual inspection to check it again modifying! Degrees of positive caster will cause a shimmy at higher speeds and excessive steering wheel to to... Wheels 20º to the hub in upper and lower ball joints per..