Was reading my Haynes about caster, have a question?

It says in my Haynes manual regarding suspension that caster is not a routine adjustment and that it only affects the self return characteristics of the steering system. Is that true?

Also is it measured from vertical? or centerline of the ball joint axis?

The way this manual makes it sound is that camber and toe are the only important issues with tire wear?

It also says caster is adjusted by adding or subtracting shims at the rear of the lower suspension arms? Where are those on my 2wd?

I'm hoping 4x4Junkie will chime in soon? Thanks, just trying to learn how to properly set up the front end here before I buy parts and get totally into something here. I've also considered your body lift idea at this point too Junkie...hahaha



Allen

well you dont have "lower suspension arms".

The best way that I can come up with to describe it would be like this.

Imagine if you took the rear end of the radius arm and moved it up and down. It would make the knuckle tilt forward and back. That is caster. How much it tilts is adjustable on a normal A arm suspension if you adjust one of the arms forward or back. on our trucks however, it is pretty much set from the factory.

There is some room for adjustment but there is much less concern about caster than camber. Since the bushing to adjust the caster is also the same one that adjusts the camber, it is very hard to get it right when doing an alignment at home.

How was that explanation?

That was perfect!

It does'nt make sense in my manual then, or it's wrong. It clearly states that that's how it's adjusted on the 93 to 97 models. I thought there were shims or something behind the radius arms I did'nt see...........lol

It also says that it's adjusted on 98 and later models by means of eccentric cams on the upper control arm pivot bolts.




Allen

You use caster to get your wheel to return to center easier and also to compensate for road crown. Too much caster and you will have hard steering and no return to center, not enough caster and you will get the 'shopping cart effect, every little bump in the road will pull you all over the place. And caster is not a tire wearing setting, just toe and camber.

Sasquatch_Ryda said:

You use caster to get your wheel to return to center easier and also to compensate for road crown. Too much caster and you will have hard steering and no return to center, not enough caster and you will get the 'shopping cart effect, every little bump in the road will pull you all over the place. And caster is not a tire wearing setting, just toe and camber.

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Hey man, you just described my ride to a "T"!!!!!!

I have the shopping cart effect (plus the pulling me all over) and was just about starting to live with it until you just posted this. How can I fix that on my own? Is there a way because my camber looks good? Thanks man!



Allen

I think I get it!

By too much you mean positive caster, and by not enough you mean negative caster right?

SO...........I think I answered my own problem. If my radius arms were not long enough for my lift that would give me too much negative caster....HENCE the harsh ride.

Please tell me I make sense!




Allen

yes caster is through the ball joint centers.that is why its hard to check in your driveway.you'd need turn plates for the tires to set on and a way to hang the gauge without taking the tires off the ground.these suspensions need to be completely settled to take measurements(no jacking up your truck).you set camber and caster together and then toe.i put a couple 80 lbs bags of concrete in the drivers seat since getting in and out of your truck changes camber noticably.also any time you put different size or offset wheels on your truck you need to realign it.and drive your truck a week or so before the final alignment(a couple small jumps and some rough stuff to settle the springs a little bit are a good thing).most shops have a wall with lots of bushing offsets so it really isen't worth the 40$-60$ for the adjustable bushings unless you plan on aligning it yourself.if its going on a real alignment machine the adjustables aren't necessary.it is nice to have an alignment machine at your disposal so you can experiment with how much caster you want.with my 10" wheels my truck is on the shallower end of caster since they travel up and down more than a narrow wheel

Hardwareman said:

I think I get it!

By too much you mean positive caster, and by not enough you mean negative caster right?

SO...........I think I answered my own problem. If my radius arms were not long enough for my lift that would give me too much negative caster....HENCE the harsh ride.

Please tell me I make sense!




Allen

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no the height of the drop brackets and the position of the balljoint eccentric determines the caster angle at ride height.the stock arms travel through a greater caster range but you woulden't notice unless the road is really rough.the longer arms have less arc but i'de say your springs and lack of weight in the front of your 2.3 truck are mostly to blame for harsh ride.the longer arms are more of a handling issue than a ride issue.as you know nobody makes engine specific springs for rbv's maybe we should pettition old man emu to make tuned spring sets for them like they do for other 4x4's

Yeah, as already has been said, caster has little to no impact on tire wear, it's for the steering return-to-center.

And no, caster should NEVER be "ignored", doing so will inevitably result in a drift to one side.
This is why the 2-piece adjustable camber bushings are nice... if the machine tells you you need +1° caster on the right side (but no camber change), you simply look at the bushing chart, follow the column over to where it shows +1° caster with the same camber, reindex the bushing, then stick it back in the beam with the correct orientation. Done!

And it IS possible to set caster DIY, but it will require a trip or two around the block to judge whether it's pulling to one side or not. Adjust it accordingly until it tracks straight.

As Junkie implied--it isn't just a Camber Bushing. It's a Camber/Castor bushing.

4x4junkie said:

This is why the 2-piece adjustable camber bushings are nice... if the machine tells you you need +1° caster on the right side (but no camber change), you simply look at the bushing chart, follow the column over to where it shows +1° caster with the same camber, reindex the bushing, then stick it back in the beam with the correct orientation. Done!

And it IS possible to set caster DIY, but it will require a trip or two around the block to judge whether it's pulling to one side or not. Adjust it accordingly until it tracks straight.

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there is the same chart for solid bushings,and as far as i'm concerned adjusting caster by just road feel alone and no gauge is like shooting in the dark.but thats just me i like to do alignments the right way

Caster is best described by the front wheels of a shopping cart, they are designed to follow the path of travel.

But from what you are describing you could have another issue plaguing you. Is your truck stock height? With Stock rims? I know that you are running 31's, and those probably aren't stock.

You might have an issue with bump steer. There are two kinds of bump steer from my determination, 'steering linkage induced bump-steer' and 'wheel induced bump steer' You might have one or both kinds affecting you depending on whether you are lifted, have stock rims and your tire size all factor into it.

rickcdewitt said:

there is the same chart for solid bushings,and as far as i'm concerned adjusting caster by just road feel alone and no gauge is like shooting in the dark.but thats just me i like to do alignments the right way

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Call it what you want...
Shooting in the dark (as you put it), you'll at least know whether to aim right or left. Eventually you'll have your direct hit.

Not everybody has a $100,000 alignment machine at their house, or cares to deal with the common TTB alignment headaches (and subsequent draining of your wallet) that come with all the ill-equipped/ill-trained (or just lazy) doofuses doing alignment work out there (no offense to those who actually KNOW what they're doing when it comes to TTB, they are a very tiny minority however).

4x4junkie said:

Call it what you want...
Shooting in the dark (as you put it), you'll at least know whether to aim right or left. Eventually you'll have your direct hit.

Not everybody has a $100,000 alignment machine at their house, or cares to deal with the common TTB alignment headaches (and subsequent draining of your wallet) that come with all the ill-equipped/ill-trained (or just lazy) doofuses doing alignment work out there (no offense to those who actually KNOW what they're doing when it comes to TTB, they are a very tiny minority however).

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It is frustrating at times aligning the ttbs, more so with the f150 and 250 than the rangers because everytime you want to change a setting you have to pull the camber/caster bushing out and turn it, put it back together and check you specs again. It does take more time than a normal alignment would but you can get pretty quick at them when you do enough of them. I probably do 1 or 2 a month.

4x4junkie said:

Call it what you want...
Shooting in the dark (as you put it), you'll at least know whether to aim right or left. Eventually you'll have your direct hit.

Not everybody has a $100,000 alignment machine at their house, or cares to deal with the common TTB alignment headaches (and subsequent draining of your wallet) that come with all the ill-equipped/ill-trained (or just lazy) doofuses doing alignment work out there (no offense to those who actually KNOW what they're doing when it comes to TTB, they are a very tiny minority however).

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she always lets me know left or right in the dark, lol.i just think the majority of the guys reading they can do it at home won't neccesarily wind up with the greatest results.
i don't know anyone with an alignment machine at their house but these guys should know that they will never get their alignment right on playing around at home.if you think about how much time you'd have to spend on trial and error and the tire life you lose in the mean time its worth the 100$ to get it done by a GOOD shop.get the before and after specs at the very least.its pretty simple to align these trucks a tech would have to be either stupid or in a hurry/lazy to not do at least a decent job.i do think it is a good idea to get it close at home and drive it a week or so to settle it,but its probably not smart to spend 600$ or more on tires and then risk scrubbing them off.if you mostly wheel with the truck and put only a few thousand a year on it like you junkie i'de say a home alignment is all you need but most people on this site drive more on the highway than dirt.now that i have a little commuter car the ranger will get more sawzall treatment and big swampers with a home alignment since you can knock them out of spec pretty easy with the big rubber,i don't see everyone else in that category though.