Lucky comparison


Caster, is a critical but often overlooked part of steering geometry that keeps your vehicle tracking in a straight line. As with anything it is a compromise and the more positive caster the heavier the steering will feel at slow speeds ( think parking lot speed ) Ford catered the behemoth Excursion to soccer moms so they didn't want heavy steering and setup the caster on the thin line between light steering feel and straight line tracking. Increasing your caster to the maximum of 5.5* recommended by ford will favor straight line tracking.

 

After my X codes, ATS mod C codes, Bilsteins, rear Hellwig 7878, new front sway bushings, new drag link ends, and all new ball joints my Ex is doing really well and drives very straight and tame. It was aligned before I did the springs and I'm about to take it back in for another alignment to see if they can get to 5.5 degrees of caster. The shop has their own source, but what's everyone's favorite for replacement caster/camber bushings in case shop has to order them. If it's true that sagging springs reduce caster, then the new springs may have increased it? Perhaps the stock bushings will be able to get me to 5.5 degrees.

 

1. Shop likely gets supplied by a distributor and has whatevery they service, moog or mevotech.

2. Anytime you change the orientation of the axle you change the caster, so yes depending on the spring a lift can increase caster. A few things come into play but if you notice the center bolt is not in the center of a leaf spring. Since the spring itself is an arch and the front is fixed it moves in a seperate arc you have a lot of movement going on. This is why every lift company recommends an alignment after installing their product.

3. stock bushing is most likely a 0* from the factory ( at least one side anyhow ) so no it will not get you to 5.5* Left and right caster can be slightly different by +\- 1* to compensate for road crown.

There are 2 types of adjusters:

Fixed, changes camber/caster a fixed amount

Adjustable. These have a double cam and can dial in a different amounts of change.

The factory uses a fixed 0* bushing.

There is also a good chance your alignment shop will use a wedge under the leaf springs to change caster. Both are acceptable if they use a steel wedge and bolt it to the leafs with the center pin. ( no slotted aluminum wedges ! )

 

Thanks Pirate, great info.

That's why he mentioned shims and I was talking bushings. I'd rather order up a set that is adjustable in case my suspension changes over time.

Any good ones to mention?

 

Honestly, I would just let your shop handle it. you will not know what you need until you get the initial settings on the alignment rack, if they do not stock the part they should be able to get it in an hour or 2.

 

Affirmative. Good advice. Thanks.

 

The caster thread has in debth info and on post 22 I put a video that shows the caster bushing selection process... this will illistrate the point

https://www.ford-trucks.com/forums/1...l#post16086297

 

Sounds like a good time (if they use shims) to have them swap the front u-bolts out while they're adding shims. I have the new set from ATS since the other vendors came in too late and I wound up re-using the originals.