My neighbor just bought a 2003 T-Bucket. The thing is almost impossible to drive over 40 mph. It wanders, seems to over steer and it is constant battle to keep it straight. Have checked all steering parts and all seem to be tight. The toe in is set at 1/16" I am assuming the caster is off. Is there any way the back yard mech. can check this setting. We have tried to adjust it with the clevis but it seems to do nothing for it. I can't see where to go without either spending $65.00 here to have it checked and not knowing whether is it at a + or - setting almost seems impossible to know where to start. Any help is greatly appreciated.
Caster Off???
- Thread starter vadatara
- Start date
a magnetic base angle finder will see where it sits now. Get the car level as possible and check where the caster is set. I use a large t-square and go from the ground to the axle kingpin boss. then use an angle finder to so how far the axle leans back from the 90 degrees point.
Check both sides. I fought suspension problems on my model A for months. I finally disassembled everything and found there was a slight twist in the I-beam causing one side so sit at 10 degrees of caster while the other side was almost 13
Check both sides. I fought suspension problems on my model A for months. I finally disassembled everything and found there was a slight twist in the I-beam causing one side so sit at 10 degrees of caster while the other side was almost 13
EX JUNK
Moderator
Get a simple degree level. They can be had at Sears, Home Depot, Lowes, etc. Place the degree level on the kingpin and you should have between 5 to 7 degrees negative caster. By that I mean, the kingpin should be leaning toward the rear at the the top of the kingpin by 5 to 7 degrees from vertical.
putz
Member
You should have a little bit more caster on the right side to counter act the crown in the road also.Usually 1/2 to 1 degree more on right.And when setting toe make sure car is not dogtracking(car going sideways down road) this can also cause handling problems.Have someone follow car down road and watch how car tracks.If frame is not square It will dogtrack and handle erractic. Not to scare are you just some ideas to help.
meangreen
Active Member
The above tips are good advice, but let's start at the beginning...
First, the car needs to be "checked for square". Get it up in the air, either on a lift or on jackstands. Check to see if the rear end is centered under the car. This is done by measuring from the rear backing plates (or caliper brackets if disc brakes) to the frame rails at the same place on both sides. The dimensions shoild be within 1/8" (or less) of the same. If not, make the necessary adjustments before proceeding.
Next, check the rear end for square. To do this, find the center of the front crossmember and mark it. (On all the chassis I build, I center-punch a permanent dimple in the center of the front cross member so I have a permanent measuring point.) Now measure from the center of the front crossmember to equal points on the rear axle. This is easy on a bare chassis, but can be a real challenge on an assembled car with the engine, trans, etc. in the way. (An offset measuring device or "tram" would be helpful here. You might be able to borrow a tram from a body shop or you can make a temporary tram from a long stick, a couple of sharpened dowel rods, and two pair of Vise Grips). The two dimensions from the outer ends of the rear axle housing to the center of the front crossmember should be within 1/8" or less.
If the rear end is centered and squared, the chassis will go down the road straight without "dog tracking". Now we can move to the front end and set the alignment. Make sure the front axle is centered by measuring from the kingpins to the frame. Next, check the front axle for square by measuring from the king pins to the already squared rear axle housing. Make any necessary adjustments to get within + or - 1/16".
Now check for caster. Caster is the angle of tilt of the front kingpins as viewed from the side. If the top of the kingpin tilts toward the rear of the vehicle, this is POSITIVE caster. On some big heavy cars like old Cadillacs and Lincolns, the factories actually used NEGATIVE caster (kingpin angle tilted forward) so the cars would be easier to steer. It worked OK on those big old land cruisers, but on a lightweight car NEGATIVE caster will cause the car to wander all over the road. To check for caster, put the car on the ground on a flat, smooth surface (garage floor?) and measure the tilt of the front kingpins. This can be done with a degree level held against the axle at the kingpin location or you can use a carpenter's framing square and a protractor. We are looking for POSITIVE caster of 5 to 7 degrees. Less than 5 degrees will cause the front end to wander; more than 7 degrees will cause the front end to shake uncontrollably. I generally try to keep my front ends closer to 5 degrees. Caster is adjusted by turning the clevises in your radius rods in or out as necessary. To increase POSITIVE caster you would want to pull the top of the kingpin back, so you would screw the top clevise in or the bottom one out.
Finally, check the toe. It should be 1/16 to 1/8 inch in. Zero toe will cause the car to wander; toe-out will cause undue tire wear and may cause front end shake. If everything is set correctly, the car should go down the road straight and smooth. Take it for a test drive; get up to about 30 mph and hit a bump with one of the front wheels. If it begins to shake uncontrollably, either something is not adjusted correctly or some component is defective. If all is well, try 40 mph, then 50. If there is vibration in the front end at highway speed, you may need to increase the toe-in slightly. You can go up to 1/4" in if necessary (this is more prevalent in really skinny tires & wire wheels).
Sorry for being so long-winded here, but the front end is the most important component of any car...
First, the car needs to be "checked for square". Get it up in the air, either on a lift or on jackstands. Check to see if the rear end is centered under the car. This is done by measuring from the rear backing plates (or caliper brackets if disc brakes) to the frame rails at the same place on both sides. The dimensions shoild be within 1/8" (or less) of the same. If not, make the necessary adjustments before proceeding.
Next, check the rear end for square. To do this, find the center of the front crossmember and mark it. (On all the chassis I build, I center-punch a permanent dimple in the center of the front cross member so I have a permanent measuring point.) Now measure from the center of the front crossmember to equal points on the rear axle. This is easy on a bare chassis, but can be a real challenge on an assembled car with the engine, trans, etc. in the way. (An offset measuring device or "tram" would be helpful here. You might be able to borrow a tram from a body shop or you can make a temporary tram from a long stick, a couple of sharpened dowel rods, and two pair of Vise Grips). The two dimensions from the outer ends of the rear axle housing to the center of the front crossmember should be within 1/8" or less.
If the rear end is centered and squared, the chassis will go down the road straight without "dog tracking". Now we can move to the front end and set the alignment. Make sure the front axle is centered by measuring from the kingpins to the frame. Next, check the front axle for square by measuring from the king pins to the already squared rear axle housing. Make any necessary adjustments to get within + or - 1/16".
Now check for caster. Caster is the angle of tilt of the front kingpins as viewed from the side. If the top of the kingpin tilts toward the rear of the vehicle, this is POSITIVE caster. On some big heavy cars like old Cadillacs and Lincolns, the factories actually used NEGATIVE caster (kingpin angle tilted forward) so the cars would be easier to steer. It worked OK on those big old land cruisers, but on a lightweight car NEGATIVE caster will cause the car to wander all over the road. To check for caster, put the car on the ground on a flat, smooth surface (garage floor?) and measure the tilt of the front kingpins. This can be done with a degree level held against the axle at the kingpin location or you can use a carpenter's framing square and a protractor. We are looking for POSITIVE caster of 5 to 7 degrees. Less than 5 degrees will cause the front end to wander; more than 7 degrees will cause the front end to shake uncontrollably. I generally try to keep my front ends closer to 5 degrees. Caster is adjusted by turning the clevises in your radius rods in or out as necessary. To increase POSITIVE caster you would want to pull the top of the kingpin back, so you would screw the top clevise in or the bottom one out.
Finally, check the toe. It should be 1/16 to 1/8 inch in. Zero toe will cause the car to wander; toe-out will cause undue tire wear and may cause front end shake. If everything is set correctly, the car should go down the road straight and smooth. Take it for a test drive; get up to about 30 mph and hit a bump with one of the front wheels. If it begins to shake uncontrollably, either something is not adjusted correctly or some component is defective. If all is well, try 40 mph, then 50. If there is vibration in the front end at highway speed, you may need to increase the toe-in slightly. You can go up to 1/4" in if necessary (this is more prevalent in really skinny tires & wire wheels).
Sorry for being so long-winded here, but the front end is the most important component of any car...
It's odd but nobody said anything about CAMBER! I have negative camber (top of both tires lean outward) on my T-buckets axle and if I have any toe-in at all, I experiance the dreaded death woble. I have played with the front end settings and found that a slight toe-out setting gives the car the best handeling, steering and tracks straight with good steering wheel return to center from turns. I do get a little wheel hop on rough or uneven roads. I have a MAS axle with SSBC bearing kin pins on 40' Ford spindles. My tires are 195-15 radials and brakes are '72 Camaro rotors and calipers.
My front suspension is very soft because I am using a CCR Chrome mono leaf spring. I believe the soft mono leaf spring is the cause of much of my wheel hop so I am installing chrome Pro-Street shocks from SpeedWay Motors and I hope that will cure the little bouncies up front.
My front suspension is very soft because I am using a CCR Chrome mono leaf spring. I believe the soft mono leaf spring is the cause of much of my wheel hop so I am installing chrome Pro-Street shocks from SpeedWay Motors and I hope that will cure the little bouncies up front.
