Front Alignment

[7212Mopar]

I worked on the alignment again this afternoon. So far PS camber 0.6 and DS camber 0.5. Toe in 1/16. PS caster is 3.5 and DS caster is 9.5. I can't seem to get both sides the same. What did I do wrong? Got the steering wheel pointing straight. Tie rod lengths are within 3/16. I got PST upper control arms and all suspension components are new and rebuilt. Should I leave the PS alone and focus on the DS? BTW, my garage is not perfectly flat and has a slight uphill slope. Concrete below both front wheels is almost dead level left and right.

[GoodysGotaCuda]

I'm not sure that much ds caster is feasible. Id recheck however you are measuring it, seems very high.


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[7212Mopar]

I know that is weird. Same gauge, same procedure. I think may be I should take a look and check the turn plate to see if it is off.

[7212Mopar]

Double check my tie rod lengths with a ruler ball joint center to center and DS and PS are the same length.

[1 Wild R/T]

Turn the wheels to full lock & use a 24" level held against the outside tire, how far does the top need to be held out from the tire to center the bubble?  Now go full lock the other way & check the same measurement on the opposite tire.... If you caster is really 9.5 degrees the difference should be about 1 3/8 inches... 

FWIW in the early 70's Mercedes was running upwards of 15 degrees of caster... Peugeot & Citroen were running even more..... When you saw one of those cars turning into in a parking space the wheel looked like it was falling over...

[Crash520]

Wild rt can you elaborate on the level thing please

[1 Wild R/T]

Wild rt can you elaborate on the level thing please

Caster is the angle of a line between the upper & lower ball joint pivot points....  Since you have no clear access to measure it the way it's done is to
"sweep" the wheels & calculate the camber change.....   What I'm suggesting it a basic caster sweep & rather than using a alignment gauge just use a simple two foot carpenters level,  degrees are a measurement the same as inches, so all you need to know is the rise & run in inches & convert it to degrees...

Oh, and thanks for bringing this back up, I got the math wrong, it's not 1 3/8"  it's closer to 2 3/4"....

And my math is wrong again.... The first measurement is close but actually closer to 1"... End of the day if they are set right they should be very close to one another...

Either way cranking the wheel to full lock is how your gonna see caster, when measuring with gauges it doesn't take full sweep, typically it's 20 degrees each way but full lock shows a higher angle...

[7212Mopar]

I am going to dig out my level and check it out. If I understood this. I am going to subtract the measurements  of the DS from PS right? Not the difference of the same wheel full in and full out?

I had been zeroing the gauge with wheel 15 degree pointing out. Turn wheel 15 degree pointing in to read gauge per Fastrac video. A Hotrod magazine article said zero gauge with wheel pointing in and then read gauge with wheel pointing out. I will try that too.

[1 Wild R/T]

All my method is trying to do is to verify from side to side to there is a significant difference....  If you have six degrees more caster on one side than the other you should be able to see/measure it.... I've never gotten more than four degrees on a typical Mopar so either you have a bent part, a poorly made part or a bad measurement... I want to double check the measurement with a basic hand tool that most guys have access to...

Hotrod vs Fastrac the result is the same, just a - vs + reading... You can also zero the bubble with the wheel straight do the sweep & add the results.... More than one way to accomplish the task... Just gotta know how to interpret the results & adjust accordingly....

[7212Mopar]

1WildRT thanks for walking me through this. DS wheel pointing right full, I got 15/16. PS wheel pointing left full, I got 13/16. So they are really close and does not explain my caster readings. I must had done something and will try some more. If I don't get anywhere, would you think this is good enough? Both sides looks almost identical.

[1 Wild R/T]

Since caster is a non-tire wearing angle  (mostly) as long as you don't have a pull you don't need to be to concerned..... What Mercedes & other manufacturers found when running 15+ degrees cornering caused tires to wear surprisingly fast....  Most new cars don't run more than 7-8 degrees...

Typically vehicles are setup with more caster on the passenger side to compensate for road crown...   Unequal caster causes the vehicle to pull to the side with the least positive caster.

[7212Mopar]

Thanks. I did the caster readings again and it is a repeat. I am thinking my garage floor is making the bad readings. This time I took pictures of how the tools change from the vertical through the sweep. Both sides look the same to me and does not explain the readings  I will post pictures when I get back. Duty calls.

[Brads70]

Are all 4 wheels on the same level surface? You mentioned turn plates, is the rear end at the same height?  like on wood or something? Tire pressures good? Torsion bars adjusted even side to side?