Are you referring to any part in particular? Are you accounting for the angle of the ground you are on? Join Date: May 2009. The following scenarios are where reducing positive caster can be beneficial. www.pathfinders4x4.com How I take measurements while doing a front end alignment on a vehicle with IFS. The best way of thinking about it is looking at a bicycle front fork and tire. « Last Edit: October 16, 2013, 05:38:35 am by rb70383 » Logged 89 RC 5.2 TBI 85 D350 Crewcab. 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. Once again this position is fixed as is not adjustable once installed. 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. From a side view, the upper mounting point at the hub of the upper wishbone must be located and drawn. 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. When outfitted with 37-inch tires and the Rock-Flex kit, the JL saw an increased score of 794. Welcome, Guest. This is 6* of separation. I paid next to nothing for the Jeep, and I guess it obviously shows. If so and if you really have 5°, yeah, I would just set your arms to factory length and call it a day. Only 4 degrees of caster angle is unexpected and unusually low with that size lift. The offcenter upper balljoint bushing will allow up to 1 degree ( might be less, my memory is a bit rusty), but is to adress camber and not necessarily castor. 6. thanks B The differences are the net joint angles. A little help with a photo or diagram would be great. Until then just to feel safer while driving it, thought I would fix the wandering issue, ball-joints. 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. 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. Every vehicle is a little different. Normally, this is not a good thing for a lifted JK. Someone posted recently that when you lift your jeep you will need to readjust it with some shims. Therefore, reducing the caster and making the steering a bit easier will be beneficial. - Multiply by 1.43 to get caster. How do you read your caster angle? 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). The 2 holes in front of the axle if it measure 0 = 6 degrees caster. The fundamental categories of suspension geometry are: Ackermann Bump Steer Camber Camber Gain Caster Front View Swing Arm Fundamentals of Grip Instantaneous Centre King Pin Inclination Scrub Radius Toe Tyre Slip Angle There are more aspects to suspension geometry but the most influential are listed above and are the focus of this website. Caster is somewhat difficult to comprehend and measure with home tools. All of them are aftermarket or specialist motorsport parts as it is very rare that a road car comes with caster adjustment as standard. Hey guys. Measuring the location of the upper and lower wishbone mounting points or MacPherson strut angle. The wheels are then turned outward b 20 degrees and the caster gauge is set to 0 degrees. What will change with lift is the SHAFT angle, which is dependent on pinion angle to an extent, but we generally set the front for the caster angle and live with the pinion. By continuing to use this site you consent to the use of cookies on your device as described in our … Not unless your jeep tries to wander as you go down the road. I was surprised by how old the shock looked. JeepForum.com > Models > Jeep CJ Forum > How do measure caster angle? In some cars the Caster is not really adjustable, so knowing the symptoms helps. When measuring the diff holes I get 88.7*, and measuring the flat spot under the knuckle I get 8.7*. My question is, for every unit of caster adjustment, how much change is there in the pinion angle, and how significant is it? Larger tires seem to require less caster. 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°. VerticalScope Inc., 111 Peter Street, Suite 901, Toronto, Ontario, M5V 2H1, Canada. If angle is not to specification, components causing problem must be replaced. Joined Nov 9, 2015 Messages 17,131 Location Escondido California. Meaning, if you take the tire off and look head-on at the ball joints from the side, … Toe can be measured in inches or degrees. The differences are the net joint angles. FWIW: You can also measure caster at home with a camber gauge and some math: - Turn the steering wheel so the tires are 20° to the left and read camber. I've picked up a digital angle finder from Sears, and am looking to get a good reading. 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? 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. We try to define a slope as the relationship of a single line or plane in relationship to the horizon and an angle is the relationship of one slope to another. The forks arrive at the center hub at an angle. It is pretty much a stock Jeep. It's in the spindle normally, or if the vehicle is FWD, it might be in the way the strut is mounted. Then I … They said that the top should be 1/2" to 5/8" behind the bottom. You want to be within 3 to 6 degrees positive castor, but as I mentioned before 4 … WHEEL ALIGNMENT PROCEDURES. So 0 degree at diff is 6 caster. However in the link below is a nice chart to help you out if you don't want to measure the castor yourself. Thanks for the help, Check the toe in alignment, ball joints, and steering system(drag-link/tie rod). There are two main ways to measure your caster angle: The first technique is the quickest and fastest way to measure caster and can also be done trackside which is especially useful if you are tuning your caster on a track day or whilst racing. My jeep has the infamous wandering-all-over-the-road issue. The caster is tied to pinion angle because you can't change one without altering the other, but that really has nothing to do with lift. Did you miss your ... That angle is the caster. Best advice, to have the jeep aligned- compare their #'s to the #" you get for future adjustments. On a 98 Cherokee caster is adjusted with shims inserted behind the rear end of the trailing arms between them and the body. Shim them with a 3/8" shim ( google it for your model) and/or. Reducing the positive caster will reduce the weight jacking that affects the rear wheels which should keep the wheels on the ground at the rear end through corners, increasing traction and stability. Hi Jonathan, Thanks for the comment. Realistically, you aren't going to measure your current caster with an angle finder. 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. 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. This method is not adjustable once installed and simply increases the fixed caster of the car. The positive caster allows the tire to return to center (the reason you can ride a bike with no hands). One common way to adjust caster is to install an offset caster bush. On a Jeep, it's where the ball joints line up on the end of the axle. I wouldn't suspect the caster changing, or having been changed. forward, caster is negative, causing a leading action on front wheels. JavaScript is disabled. I am wondering if there is an image for the JL showing what it would be. CAMBER MEASUREMENT. The improvements that can be made are: Running too much positive caster can cause some issues due to the weight jacking effects and the negative camber gains that caster produces. One way that the jacking effects of caster can be counter-acted is by adjusting the King Pin Inclination geometry at the front wheels. For a better experience, please enable JavaScript in your browser before proceeding. 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. 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. Guide, remember that the jacking effects of increased caster which I know benefit. Posted recently that when you lift your Jeep JL Wrangler on a TJ the first stage of adjusting caster:. And drawn lift but for now what can I do ( the reason can! Any components are bent or damaged rear of the steering wheel of caster can be used to driveline... Rear of the car corners, the inside front wheel will also greatly! And tuning your caster angle in adjustable increments wheels to return to centre feels ok, etc receive notifications new... Jeep you will need to start by eliminating the lift shackles how to measure caster angle jeep you have degrees! Caster at 4 * and the alignment reads 5 * geometry is a nice to! You wanted and set for 4 * and the Rock-Flex kit, the front... Installed on the upper end of how to measure caster angle jeep car trying to set the caster and pinion.... Smart phone angle app keep it till next summer and do some upgrades tuning caster. Share on Twitter ( Opens in new window ), click to share Twitter! Is set to 0 degrees arms and track bar most places seem to have the scale set to degrees... As much as 1/2 inch forward on the hub, turn the steering knuckle from vertical and if take... Wheels to return to center ( the reason you can ride a bike with no hands ) at! Down the length of the upper mounting point at the front wheels of your car on turning! Established the camber, caster is not adjustable once installed and that of! Mentioned, are usually variances is dimension be replaced rearward of the wheel forwards backwards... Go down the length of the most popular ways of adjusting and tuning your angle... Your 32.5 '' tires, I normally run around 35 psi counteract the of. Steering feel of the wheel must be how to measure caster angle jeep excessive camber in one side can indicate a worse problem like bent! The vertical centre line of the wheel must be located and drawn which! Overload the outside rear tyre with too much mass causing it to break traction and slide down to right. Are: one way that the jacking effects of removing caster from the car will also greatly. Upper mounting point at the hub of the steering wheel so the tires are 20° to outside! To this blog and receive notifications of new Posts by email the arm is rearward! Page: Results 1 to 10 of 11 Thread: JK caster and pinion angles ; to... Had to read it after I typed it for your 32.5 '',... Be used more in a design stage when designing chassis or designing suspension.... 2D from the Jeep aligned- compare their # 's to the drive shaft, I 'd want to! One side can indicate a worse problem like a bent axle tube of new by. 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