Caster on straight axle Packard....

[Spitfire8]

With steering wheel centering resolved, it's time to double-check wheel-caster on the '36 1401, as this affects directional stability and steering ease. Shop manual says 2.5 degrees, but offers no additional info. So:

1) Was caster built-in to the axle/steering knuckles?

2) Or, was caster on these cars supplied by the addition of shims between axle and springs?

3) If shimmed, I assume caster was positive, with shim at front of axle. (Although an old mechanic's book I have says some vehicles used negative caster).

Sorry about the "technical-eeze" here, but I recently bought a 4-post lift, which provides the opportunity to see areas on a Packard that generally should not be viewed by civilized society.

Given this view, a few tools and too much spare time, one starts investigating and questioning things that would otherwise remain obscure and untouched!

Thanks for any input!

[Packard Library]

Bill,

Caster is not built into the steering knuckles. that is called king pin inclination. Caster on those early cars that have a straight axle is the forward and rear tilt of the axle which is done by tapered shims which are inbetween the axle and the spring.

Camber is the inward and outward tilt of the wheel.

both are checked with a bubble gauge now they use a digtial meter which is attached to the hub of the wheel.

it is always best to follow the factorys recommendations - why because they tested the front end with these specs and most likey felt that the vehicle performed better with these specs.

basically, the rule of thumb is setting a car with negative caster provides easier steering at low speeds but loses stability and higher speeds. postive caster creates better stability at higher speeds but, becomes harder to steer at lower speeds.

one must remember too that many times techinicans adjusted caster differently on each side in order to deal with local conditions such as camber in the roads. one must set the car and then drive it to see if it pulls to one side or the other. toe out or toe in can also create a pull just as uneven tire pressure. toe out on turn is a different measurement. a layman can make sure that the tire pressure is correct and the wheel and tire are balance as a unit. if the vehicle lacks stability, pulls, or shimmys take it to a person who has experince with and has the equipment. Before you even begin to work on the front end you must make sure that the steering gear is adjusted and working correctly. as this can also cause wander. Bad or worn shocks must be corrected prior to adjusting the front end.

rule one is if you are having stalibity problems - the front end components must be in good condition before any alignment is done.

hope this helps

my over all recommendation is to let it. remain obscure and untouched! unless you know what your doing.

Dave Schumacher

[Rusty_OToole]

Truck repair garages are used to setting up straight axles.

Here is a tip. Set up your axle with minimal caster and add a steering damper. It will make the steering easier and more accurate while the damper prevents shimmy. Just a suggestion.