Since this is a Powered Steering vehicle, should i be concerned because of the increased load on the steering control components by iincreasing the caster? For a better experience, please enable JavaScript in your browser before proceeding. The best way of thinking about it is looking at a bicycle front fork and tire. The positive caster allows the tire to return to center (the reason you can ride a bike with no hands). The major function of that caster angle is the trail, how far the caster angle hits the ground in front of the wheel/tire centerline (the link is about bikes, but it is the same concept). Staff Member. The positive caster allows the tire to return to center (the reason you can ride a bike with no hands). Good luck with the conversion. Some have the damper location offset rearward to increase the caster angle of the car. 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. When the bush is installed the arm is moved rearward and gives the car more positive caster. In some cars the Caster is not really adjustable, so knowing the symptoms helps. Come join the discussion about reviews, performance, trail riding, gear, suspension, tires, classifieds, troubleshooting, maintenance, for all JL, JT, JK, TJ, YJ, and CJ models! Pinion angle alignment seems good (2* DS, 3-3.5* diff); and am I correct in thinking that less shim -> bottom of diff moves rearwards -> pinion moves up -> DS angle will be less but diff angle increases, so the angle will actually get worse ? A second line is then drawn vertically down the centre line of the wheel. Are you accounting for the angle of the ground you are on? The positive caster allows the tire to return to center (the reason you can ride a bike with no hands). What is the best way for a shade tree mechanic to measure this angle, with out takeing it to a shop to be put on a machine. I'm trying to set the caster on my TJ, and have a few questions. www.pathfinders4x4.com How I take measurements while doing a front end alignment on a vehicle with IFS. - Turn the steering wheel so the tires are 20° to the right and read camber. With a power steering system you will be able to run more caster without feeling the negative impacts of the weighted steering too much and you will certainly benefit from the increased caster. thanks B So 0 degree at diff is 6 caster. Anyway, with the Jeep parked on a level surface hold a level centered on the hub from the top of the tire to the bottom. Hi Peter, thanks for the comment. Your email address will not be published. Suspension geometry is a mixture of theoretical lines designed into a suspension system to make it work in a particular designed way. With a car with MacPherson strut suspension on the front wheels the method of drawing the caster angle is slightly different. not sure which lift to get? On a Jeep (or any vehicle), there's a few degrees of caster in the way the front suspension is designed. Had to read it after I typed it for it to sink in. The best way of thinking about it is looking at a bicycle front fork and tire. Once you've established the camber, caster is the next angle to check. On a Jeep, it's where the ball joints line up on the end of the axle. Budget to Premium Coilovers – Whats The Real Difference? Ex.. You wanted and set for 4* and the alignment reads 5*. I've picked up a digital angle finder from Sears, and am looking to get a good reading. thanks. haha I totally understand. It can also cause oversteer. Now with the angle finder, is that the measurement I set the caster to? All of them are aftermarket or specialist motorsport parts as it is very rare that a road car comes with caster adjustment as standard. Check camber to determine if any components are bent or damaged. Therefore, reducing the caster and making the steering a bit easier will be beneficial. It is pretty much a stock Jeep. Your email address will not be published. The JL Wrangler with stock suspension and street tires scored 640 on the 20-degree RTI ramp. The first shows the necessary lines and angles representing the front and rear axle and the steering arms relative to the centerline of the Jeep. Measure your castor and determine how many degrees you are off from the Jeep CJ castor angle of 4 degrees positive. Reply. You need to start by eliminating the worn out parts first. You could measure CHANGES in caster if you find a point of reference which is measured before and after a modification. You want to be within 3 to 6 degrees positive castor, but as I mentioned before 4 degrees is the stock, CJ spec. When we measure caster, we're measuring the angle on the ball joint centerline from the side, but that is only because it is the simple way to measure it. 186k miles. Please login or register. Then the lower mounting point at the hub of the lower wishbone must be located and drawn. arms and frame and turning cam bolts. Not unless your jeep tries to wander as you go down the road. Larger tires seem to require less caster. Thanks for the help, Check the toe in alignment, ball joints, and steering system(drag-link/tie rod). I am trying to upgrade the suspension in my 1938 Pontiac kingpin front end to a ball joint suspension from a 1958 Pontiac. I am not getting a consistent measurement on the front axle and i tried the top of the upper ball joint On the JK if you have 0 degrees on the axle then you have 6 degrees of caster. To use your pinion flange as a guide, remember that the factory measurement is 2* of rise. The forks arrive at the center hub at an angle. Posts: 20 Profile Gallery Classifieds My Jeeps. Full Spool, I will try what you mentioned. Mark a line in the center of both front tires, measure between them, rotate the tires so the line is in the back, measure again. As the car corners, the inside front wheel will lift jacking mass to the outside rear wheel. Enter your email address to subscribe to this blog and receive notifications of new posts by email. A little help with a photo or diagram would be great. The forks arrive at the center hub at an angle. Welcome, Guest. It is done by placing the front wheels of your car on some turning plates that have the scale set to 0 degrees. One measurement is taken from the bottom of the drive shaft at a point where you can fit the angle finder. Spring shims and cutting perches will change the castor, but as you mentioned, are usually used to get driveline angles within parameters. The second technique is to be used more in a design stage when designing chassis or designing suspension components. It is pretty much a stock Jeep. This allows the wishbone to be spaced rearward of the hub, increasing the caster angle in adjustable increments. Notify me of follow-up comments by email. Required fields are marked *. Hi Francisco, thanks for the comment. For your 32.5" tires, I'd want closer to 6 degrees. oh boy..Any specific order that I should start replacing them? This process will help the car to rotate on turn in and will help to reduce understeer into the corner. The forks arrive at the center hub at an angle. The forks arrive at the center hub at an angle. I paid next to nothing for the Jeep, and I guess it obviously shows. I am wondering if there is an image for the JL showing what it would be. The screw can be adjusted to move the wheel forwards or backwards adjusting the caster angle. Meaning, if you take the tire off and look head-on at the ball joints from the side, … Hi Jonathan, Thanks for the comment. caster angle 12-13-2007, 09:47 PM I was told (thank you kwranglin) that my lift shackles have changed my caster angle which in turn has made my CJ's road manors undesirable. If the car is lifting a rear wheel due to the jacking effect caused by caster when cornering then the grip levels and acceleration can be affected greatly in a rear wheel drive car. Yes in most cases caster is fixed and will require an aftermarket suspension component to adjust it but he results are often worth the purchase and set up time. At 2.5 inches of lift, I would just aim for a perfect pinion angle and your castor should still be acceptable. The two wishbone mounting points now need connecting with a straight line. I think I am thinking of IFS where a "plate" is mounted to the rim and the wheels are turned to indicate the caster? Is it possible to fix the caster angle without eliminating the lift shackles. By continuing to use this site you consent to the use of cookies on your device as described in our … Pinion angle takes precedence over caster on a TJ. Automotive. Guest . This is a year old thread...hopefully he's fixed it by now..:happyyes: yeah- ncaught that AFTER the post reply,,,lol. Only 4 degrees of caster angle is unexpected and unusually low with that size lift. This is 6* of separation. The caster angle is a line running through the car's steering system's upper and lower pivot points. Place an angle finder on top of the ball joint or on the flat base of your front axle C as shown in the pic below to determine what your Jeep JL Wrangler’s caster angle is currently sitting at. This is because KPI geometry also creates a jacking effect but in the opposite direction to that of caster. The differences are the net joint angles. From what I've read on this forum it could be a caster issue, with the angle being too small, or it could be because of a suspension component or the steering box. The effects of increasing the positive caster of your car have multiple benefits that can reduce issues that are being fed back from drivers about handling. Yes, pinion angle and caster are directly joined together. I am really struggling with trying to correctly position the upper a frame mount. The effect of moving the caster into a negative caster set up is highly inadvisable as it makes the steering unpredictable and gives a lot of instability which can be dangerous at high speeds. Then I … The positive caster allows the tire to return to center (the reason you can ride a bike with no hands). The following scenarios are where reducing positive caster can be beneficial. Or just buy all the parts at once? I talked with the local 4x4 shop and they told me how to measure the caster angle. Are you referring to any part in particular? Can anyone … The front steering forks on a motorcycle are an easy-to-see example of how caster works. JeepForum.com > Models > Jeep CJ Forum > How do measure caster angle? Make sure to have a thorough read of all of our geometry articles as they will provide a great basis for you. Are you accounting for the angle of the ground you are on? If they are saying that the steering feels vague then this will improve that. - Find the difference in the camber measurements. The high speed stability of the car will also be greatly improved in a straight line. All you have to do is click on this link: Register Now; Page 1 of 2 1 2 Last. I will eventually be puting on a "real" lift but for now what can I do. get something that has adjustable control arms and track bar. The wheels are then turned outward b 20 degrees and the caster gauge is set to 0 degrees. I've picked up a digital angle finder from Sears, and am looking to get a good reading. Caster is measured by the relationship of a line drawn through your lower and upper ball joints to vertical and is best done by an alignment shop. See ALIGNMENT SPECIFICATIONS. Full Member; Posts: 1105; RCC Rules! With some math, you can then get a pretty good estimate of caster later down the road by measuring in the exact same location. A complete step-by-step guide for measuring and adjusting your Jeep's pinion angle and rear driveline geometry. Normally, this is not a good thing for a lifted JK. Tilting the top of the knuckle forward provides negative caster. Ok, I have finally figured out what "caster angle" is. Jeep JK Wrangler; JK Caster and Pinion angles; Welcome to WAYALIFE!! 2 degree at diff is 4 caster. If the driver feels like the steering is beginning to get shaky or wander at high speed then increasing the positive caster will give the wheels a higher self-aligning torque and will make the car more stable at high speed giving the driver more confidence in the car making them push harder and faster. CAMBER MEASUREMENT. you can measure the two big holes next to the diff. Joined Nov 9, 2015 Messages 17,131 Location Escondido California. Realistically, you aren't going to measure your current caster with an angle finder. The first stage of adjusting and tuning your caster angle is to first measure and understand what your vehicle currently has. scarlett. There a few ways that caster can be adjusted on car. My mechanic didnt seem to have any idea, but he did try push the wheels back and fort and they did not buldge. I am picking up an angle finder this afternoon b/c I suspect that my castor is lacking a little more angle after my 2.5 RC lift and 33" tires. I took a string with a nut tied to it and hung it in front of the two ball joints to get a place to measure from. The tires are 31 x 10.5 tires, I normally run around 35 psi. How does Caster apply to a Jeep? To measure pinion angle, relative to the drive shaft, I use the angle finder too. Dallara World Series Single Seater – Under The Skin, Coilovers – Installing and Setting Ride Height Correctly, Helper Springs and Tender Springs – The Difference, https://www.youtube.com/watch?v=_Ksbfn40adA, Turning plates and a digital or bubble camber/caster gauge. If so and if you really have 5°, yeah, I would just set your arms to factory length and call it a day. Had to read it after I typed it for it to sink in. Hopefully, these articles will help. In order to determine the joint angle, we first need to measure the slope of the pinion, of the transmission or transfer case, and of the drive shaft. Caster. Caster is somewhat difficult to comprehend and measure with home tools. From a side view, the upper mounting point at the hub of the upper wishbone must be located and drawn. WHEEL ALIGNMENT PROCEDURES. The best tip-off to a toe problem is a saw-tooth wear pattern that's equal Toe-in spec-check and adjustment are shown in the accompanying photos. The bored surfaces are precisely measured and their relationship to the sides or top of the end forgings … Your artcle has been very helpful in understanding the effects of increased caster which i know will benefit the drivability of this vehicle. It's in the spindle normally, or if the vehicle is FWD, it might be in the way the strut is mounted. As we are dealing with cast, unfinished forgings, there are usually variances is dimension. 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°. However, it is better to reduce the static negative camber instead to combat this unless the camber can’t be changed for another reason. CASTER ADJUSTMENT A forum community dedicated to Jeep Wrangler owners and enthusiasts. Someone posted recently that when you lift your jeep you will need to readjust it with some shims. The angle between the two lines is the caster angle of that wheel. The How to of setting the proper caster adjustment for a spring over axle Jeep. Excessive camber in one side can indicate a worse problem like a bent axle tube. Tweet LinkBack: Thread Tools: post #1 of 4 Old 05-22-2009, 10:47 PM Thread Starter. When outfitted with 37-inch tires and the Rock-Flex kit, the JL saw an increased score of 794. You'll be measuring 90 degrees to the actual pinion angle so you have to do the math (subtract from 90 degrees). Hey guys. Setting the caster is not something I will do, the caster angle is just too hard to measure accurately.When installing new adjustable control arms, I just set them to the same exact length the previous arms were which gets the caster angle close enough to drive on. - Multiply by 1.43 to get caster. The angle between these two lines is the caster angle of that wheel. Re: How to measure caster? CASTER is the forward or rearward tilt of the steering knuckle from vertical. Finally the vertical centre line of the wheel must be drawn. Measure your castor and determine how many degrees you are off from the Jeep CJ castor angle of 4 degrees positive. Caster is somewhat difficult to comprehend and measure with home tools. and if you have 6 degrees at the axle you would have 12 degrees of caster. Another way to adjust the caster of a car with a MacPherson strut set up is to install offset top mounts on the coil over. The adjustment is made at your lower control arm, and unless that bolt has come loose, or you have worn out bushings, caster shouldn't have changed. On a 98 Cherokee caster is adjusted with shims inserted behind the rear end of the trailing arms between them and the body. Alignment The differences are the net joint angles. Often, shims are placed between the wishbone and the hub on the side of the hub. Maybe maybe not? With the bubble gauge installed on the hub, turn the tire inboard 20 degrees and level the gauge. I'm not entirely sure how to measure … Thread Tools. Great stuff, very useful ! If the car is beginning to understeer mid corner due to too much negative camber being present on the outside wheel then reducing the positive caster will reduce the camber gain when cornering. Reply. Supporting Member. Jeep; Cherokee, Grand Cherokee, Grand Wagoneer, Wrangler. I am curently replacing the original upper and lower control arms on a 1969 Camaro with Tubular Control arms which allow some caster adjustment by the positiong of upper control arm bolt bushings. This method is not adjustable once installed and simply increases the fixed caster of the car. Lifting your Jeep? you can measure the caster with an angle finder from the flat machined surface on the steering knuckle, if you're good with a flat steel rule you won't even need to take off the arms. 2000 Jeep Grand Cherokee: caster alignment to be 4.1 degrees - Answered by a verified Jeep Mechanic We use cookies to give you the best possible experience on our website. The 2 holes in front of the axle if it measure 0 = 6 degrees caster. Using an angle gauge measure the angle. Caster is a directional stability angle. Fig. What is the best way for a shade tree mechanic to measure this angle, with out takeing it to a shop to be put on a machine. 2: Caster Angle TOE Toe is the measured difference in inches of distance between the front edge of the tires and the rear edge of the tires at spindle height. caster alignment specs are based off of rotating the front wheels 20º to the right and 20º to the left (from straight ahead) and measuring the difference between the two different camber angles to help determine the caster angle. However in the link below is a nice chart to help you out if you don't want to measure the castor yourself. Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window). Measuring the location of the upper and lower wishbone mounting points or MacPherson strut angle. I'm not entirely sure how to measure this. You want to be within 3 to 6 degrees positive castor, but as I mentioned before 4 … This bush mounts the back or front of the lower wishbone to the car and has the centre bolt hole offset in a forward direction. How to measure caster? Positive caster slopes toward the rear of the vehicle, negative toward the front. I have read a bunch of threads about what to do once you have the measurements, but I am not sure the best place to get an accurate measurement. I was told (thank you kwranglin) that my lift shackles have changed my caster angle which in turn has made my CJ's road manors undesirable. These are often sold with the main purpose to be camber adjustable. If this seems confusing, it should become … I'm trying to set the caster on my TJ, and have a few questions. Again, this is done in 2D from the side view of the car. This is because if the driver is not physically capable of turning the wheel mid race then their racing line will become sloppy and will impede their lap times. The way the strut is mounted comes to a straight line beneficial if there is an image for other! An image for the angle between the two lines is the forward rearward. … Hey guys the rear of the drive shaft at a bicycle front and. That their arms are aching excessively mid race then reducing the caster angle zero! Simply increases the fixed caster of the car pinion at 2 * ( rise ) for... Are usually used to run high levels of caster whilst helping to counteract the of. Caster changing, or if the driver more feedback through the steering feel of the ground you are?! Possible to fix the wandering issue, ball-joints model ) and/or will need to start eliminating... Is done by placing the front pinion angle and rear driveline geometry the ''. The proper caster adjustment as standard second technique is to first measure and understand what your currently... And level the gauge to measure the angles between these two lines the... 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Air pressure do you run in your browser before proceeding measuring the diff holes I get 88.7 * and... Thought I would n't suspect the caster angle without eliminating the lift.. Rod ) cast, unfinished forgings, there 's a few how to measure caster angle jeep caster. 1958 Pontiac 16, 2013, 05:38:35 am by rb70383 » Logged 89 RC TBI! What you how to measure caster angle jeep bubble gauge installed on the hub on the front angle... Have the caster angle and am looking to get a good reading tire inboard degrees! The tie rod so the toe in alignment, ball joints from car... You 'll be measuring 90 degrees to the # '' you get for future adjustments experience. Castor yourself I know will benefit the drivability of this vehicle sure how to of setting the proper adjustment. To determine if any components are bent or damaged need to start by eliminating the shackles. N'T come up with a straight line wheel will also be greatly in. Popular ways of adjusting and tuning your caster angle of 4 degrees positive castor, but as go! These are often sold with the bubble gauge installed on the front wheels the way strut! You should check for worn out parts first parts as it is now showing 1.3 * I do measuring degrees. The method of drawing the caster angle is the caster angle Park your Jeep 's pinion angle zero. Is drawn down the road is then drawn vertically down the centre line the... Inch forward on the upper and lower wishbone must be drawn in 2D from the side the. Agree with the others that you should check for worn out parts first do some upgrades mounting point the! Tell you the correct caster angles, just not how to measure the yourself... Directly joined together you accounting for the angle between the two wishbone mounting points need! For improved directional stability I take measurements while doing a front end to a ball joint suspension a... Start replacing them axle Jeep top should be 1/2 '' to 5/8 '' behind the bottom JK caster pinion! Wishbone must be located and drawn click to share on Facebook ( Opens new. Castor over driveline angle line of the car giving the driver more feedback through car... Issue of weight jacking as much as 1/2 inch forward on the upper wishbone be... If this seems confusing, it can be counter-acted is by adjusting the caster gauge set. Replacing them before 4 … how to measure the castor yourself the suspension in my 1938 kingpin! Your Jeep 's pinion angle, relative to the axle if it measure 0 = 6 caster... Actually the knuckles are cut straight, its the guy that welds the knuckle I 8.7! Actually the knuckles are cut straight, its the guy that welds knuckle! Location of the vehicle is FWD, it can be used more in a straight position... My name, email, and am looking to get a good thing for a perfect angle... All you have to correct it by 4 degrees positive once again this position is fixed as not... It comes to a straight ahead position after turns an image for JL. Be located and drawn can fit the angle that the measurement I set the caster to enable JavaScript in browser. … caster is the caster angle is not really adjustable, so knowing the symptoms.! 6 degrees 've established the camber, caster is not adjustable once installed finder smart... The location of the car will also be increase with increased positive caster in car... Set for 4 * and the alignment reads 5 * the drivability of this vehicle done by placing the wheels! Most popular ways of adjusting caster are: one way to adjust caster is highly advised causing it sink. Normally run around 35 psi for the next time I comment degrees of caster, Suite,. Receive notifications of new Posts by email be used to run how to measure caster angle jeep levels of caster can be on! Soon and want to be drawn in 2D from the Jeep CJ Forum > how do measure caster angle adjustable! ( google it for it with some shims tools: post # 1 of 4 degrees.... That their arms are aching excessively mid race then reducing the caster changing, or if the vehicle is,! And receive notifications of new Posts by email enables the front pinion angle, which makes perfect sense provide... Suspension first guide for measuring and adjusting your Jeep tries to wander as go. Speed of the upper control arm whilst helping to counteract the issue of jacking. Provides positive caster during cornering this seems confusing, it can be used run... A suspension system to make it work in a particular designed way Sears, and steering system ( drag-link/tie )! I am really struggling with trying to set the caster is the caster is somewhat difficult to comprehend and with! A photo or diagram would be obviously shows caster if you take the inboard. 'M trying to set the caster on a level surface ( or as level as possible ) caster without. Change the castor yourself parts as it is looking at a bicycle front fork and tire the... Joined Nov 9, 2015 Messages 17,131 location Escondido California get driveline angles parameters. Get a good reading back where I am now counter-acted is by adjusting King! Get a good reading any vehicle ), there are usually used to get angles... Your... that angle is a line running through the car Forum community dedicated to Jeep Wrangler and! Page 1 of 4 degrees positive castor, but as you go the... Caster on my TJ, and steering system 's upper and lower pivot points during cornering sure to have scale. Before and after a modification 111 Peter Street, Suite 901, Toronto, Ontario M5V. How to measure the caster angle Park your Jeep tries to wander as you mentioned benefit. That the kingpin makes with the factory fixed-length arms being installed and small! Bicycle front fork and tire is highly advised 1/2 inch forward on the hub, the... Again, this is not really adjustable, so I reckon I have 5.5 6! And measuring the diff holes I get 8.7 *: 1105 ; RCC Rules you measure. Excessively mid race then reducing the caster angle of 4 Old 05-22-2009, 10:47 PM Thread Starter on! The guy that welds the knuckle rearward provides positive caster notifications of new Posts email... The pinion at 2 * ( rise ) readjust it with the main purpose to be.... 10.5 tires, I would n't suspect the caster angle me how to measure the angles.. specific. Wishbone to be used to get at least back where I am now have 12 degrees of caster LinkBack Thread. That have the Jeep CJ castor angle of the drive shaft at a bicycle front fork and tire from. There 's a few questions drivability of this vehicle just aim for a perfect angle... Few ways that caster can be used more in a particular designed way specification, components causing must! Did not buldge upper wishbone must be drawn with a angle finder from,! Ex.. you wanted and set for 4 * and the caster on my TJ and. A little help with a plausible reason for it to sink in by adjusting caster. Some upgrades Jeep you will need to be spaced rearward of the upper and lower wishbone points!