'69 B Body Alignment Specs.

[mrhemi]

Apologies if the query has been answered previously, however a search did not come up with the exact question.

I have just replaced the rear springs and torsion bars on my '69 Charger R/T. Will be setting the ride height to stock specs and getting an alignment done. All suspension components are stock with only about 18000 miles on them. I realize the current thinking is to get as much caster into it as you can, especially if using radial tires. Now I just noticed that the FSM manual lists a different caster spec for manual steering (-1/2 deg.) as opposed to power steering at (+3/4 deg.). I do not know what it was aligned to previously.

Is there any reason not to adjust to maximum positive caster with the manual steering? I assume the original thinking was to make it easier to armstrong the steering wheel. The car will normally be on P255/60R-15 radials on 8" rims. Occasionally will be fitted with stock F70-15 redlines.

Thanks in advance.

 

[Cranky]

Radial tires? If so.....I refuse to go by the book!

 

[mrhemi]

Radial tires? If so.....I refuse to go by the book!

Hence the question. But what about the difference between an manual and power steering box having different specs.?

 

[R/T Boy 67]

I would go -1/2 on camber and as much positive caster as you can get, with the stock components.

 

[Cranky]

I generally go with what makes the car handle better.....stock parts or not. Usually, stock parts won't give what I like but sometimes they will give what I want on some cars.

 

[BLK 68 R/T]

I think pretty much general consensus for a normal street driven car with radial tires. -.5 to -.75 degrees camber, 1/16” toe in and +3 or 4 degrees caster. Probably tough to get with all stock components unless you have the offset upper control arm bushings or aftermarket tubular or adjustable ones.

 

[1 Wild R/T]

I think pretty much general consensus for a normal street driven car with radial tires. -.5 to -.75 degrees camber, 1/16” toe in and +3 or 4 degrees caster. Probably tough to get with all stock components unless you have the offset upper control arm bushings or aftermarket tubular or adjustable ones.

I rebuilt the front end on a Dart recently, with the offset UCA bushings I was able to get 7 degrees.... Car drives incredible...

 

[myk r sanchez]

NEGATIVE DEGREE caster settings? Gross.

My settings:

6* positive caster
1* negative camber
1/16 toe in

You wont get caster settings like that without aftermarket UCAs or the offset bushings, but the closer you can get to those specs the better your car will handle. It will surprise you...

 

[rww124]

NEGATIVE DEGREE caster settings? Gross.

My settings:

6* positive caster
1* negative camber
1/16 toe in

You wont get caster settings like that without aftermarket UCAs or the offset bushings, but the closer you can get to those specs the better your car will handle. It will surprise you...

What would be the max positive caster you could get with a Super Bee's stock suspension (I have radial tires) and will increasing the caster by positive 2 or 3 throw out your camber and/or toe?

 

[Mackman]

Hence the question. But what about the difference between a manual and power steering box having different specs.?

Less caster for the manual steering to lessen steering effort.

 

[rww124]

Less caster for the manual steering to lessen steering effort.

I have power steering and radial tires so let's focus on that.

 

[Kern Dog]

NEGATIVE DEGREE caster settings? Gross.

My settings:

6* positive caster
1* negative camber
1/16 toe in

You wont get caster settings like that without aftermarket UCAs or the offset bushings, but the closer you can get to those specs the better your car will handle. It will surprise you...

What would be the max positive caster you could get with a Super Bee's stock suspension (I have radial tires) and will increasing the caster by positive 2 or 3 throw out your camber and/or toe?

The guy that you quoted and asked for advice made the post over 5 years ago. Myk was a cool guy but has not been on this forum for a few years now.
These cars are designed in a way that as the suspension compresses and the front gets lower, the caster drastically increases. See the chart...

The amount of caster that you can get aligned to matters a LOT on where you have the ride height set. The lower you are, the more caster you can get.
Caster aids stability. It makes the steering want to go straight and stay straight. Negative caster makes the steering want to wander and follow whatever cracks, bumps or crown the road has. In short, you never want negative caster, ever.
You want some negative camber too. Not a lot of it but some. I have 3 cars of mine here that I aligned myself and all have at least 1/2 degree of negative camber. This car....

....has aftermarket upper control arms that allowed me to get 8 degrees of POSitive caster, a full degree of negative camber and 1/8" toe in. It does not wander, it does not pull to one side, the tires are wearing normally.

To answer your last question.....
Caster will not affect tire wear. Camber won't either if it is around 1 degree or less. It is the TOE that chews up tires. Toe OUT with negative camber causes a scrubbing action on the inner edges of the tires and that wears away the tread pretty fast. Too much toe IN will wear the outer edges of the tires for the same reason.....the tires are fighting each other and scrubbing on the pavement.
You do want a very slight amount of toe IN though. The tire's (even slight) resistance to rolling pushes them rearward slightly, in effect it is toe-ing them out so a little toe in is like a "pre-load" to act against it.
Cheers....

 

[Cranky]

I have power steering and radial tires so let's focus on that.

Does your car wander at freeway speeds? Good test is on a known flat highway and if you have to continually correct, it needs more caster. If you have an area where you can go faster and it still wanders a bit, add a bit more caster. You also have to pay attention to the rest of the adjustments when making any adjustments. Keep in mind that not all Mopars are the same....what works for one might not work for another.

 

[AR67GTX]

Now I just noticed that the FSM manual lists a different caster spec for manual steering (-1/2 deg.) as opposed to power steering at (+3/4 deg.).

Is this right for manual steering - negative caster? How the heck would negative caster work? Seems like it would drive like a wonky shopping cart from Walmart.

 

[BLK 68 R/T]

Is this right for manual steering - negative caster? How the heck would negative caster work? Seems like it would drive like a wonky shopping cart from Walmart.

Keep in mind those specs were for bias ply tires and the more narrow crowned roads of the day. The engineers back then were trying to compensate for that.