Caster (lack of):

If you can, get the measurements, I would like to see. Camber isn't always perfect. That is one of those "ballpark" things. Slightly out of tolerance won't hurt. In fact, if they are positive on the left and negative on the right it will help counter road crown. Eaton axles are always the best as far a being close to the specs. Camber is no longer adjustable, it is no longer an accepted practice. The manufacturing process is different now and so is the metallurgy. The beams don't respond to bending very well.

 

Heavyd,

Oh the camber ain't out by much. It just isn't perrrrrfect.
What would you set caster on a '96 Fr8lnr FLD set fwd EFA12?
I'd like to compare to what my guy suggests.


How does extreme caster affect tire wear compared to minimal caster?


On a side note, google "youtube" and "camber" to see what these nuts are doing to their cars! I don't get it!?!

 

I served my 5 year apprenticeship at a Pete dealership, then I drove truck for 2 years. This combination has helped better me as a mechanic in understanding drivers issues and satisfying those issues.
For the last 26 years I've run a 14 bay shop. I perform and train techs in alignment. We are the only shop in the area that can bend an axle in the truck, so we are very busy with our rack.
Cast axles can all be bent in the truck to correct camber, the story told by the manufacturers is a fairy tale.
The best way to compensate for road crown is though camber stagger. This eliminates any pull and offers maximum tire life to our customers.
Our customers are very happy with our alignment techniques. Their trucks drive good and they save a fortune in steer tires.
It is never my intention to attack or question yours or anyones integrity by my statements, I am very open minded and always learning new things from you and others. I also have no need to be "King of the hill", so if you have that need, go for it, I've worked with hundreds of all types and many approach me today and say to me "You know what, I wish now I would have just listened". It reminds me of when I was young and we laugh it off together.
Famous last words: There are many ways to do the job, but only one best way, so let's do the job to best serve the customers needs in the most efficient manner and you will have a happy customer for life and he will bring all his friends.

 

Ok, that's cool. If that is working for you then that is great. We have a Hunter rack and use to have all the beam bending stuff. I went to Hunter alignment school in St Louis and they told us then to take a torch and cut up all our camber bending tools and get rid of them. I have just heard from too many sources to not bend beams, including trade school and Eaton driveline training. I really never heard from anyone that does. I have worked at the same shop since high school. I learned from a 20 year alignment veteran who would never bend beams because it was dangerous. The pressures and stresses needed to make the bends are so high, if anything let go and you are in the way, wow! The instructors at Hunter said the same thing, they don't even sell the stuff anymore due to liability and recommend if you do it needs to be behind a double concrete block wall with bullet proof glass and use remotes. My view point on camber/caster adjustments is not to secure the throne at the top of the hill. I believe there is safety issue there and I have never seen anywhere that any manufacture allows you to bend their axle. That is just how I was always taught and trained. I surely don't know it all, and I love to learn new stuff. I am kinda a by-the-book person. If you have anything that says you can bend beams I would love to read it! We don't have our camber tooling anymore, but I will certainly agree with you that trucks do need some better camber stagger. Since we don't get into that, caster is all I have. You didn't say you bent beams in the earlier posts so I thought you might be doing your customers a dis-service by taking out caster stagger. I was honestly trying to help.

 

I would be happy with 4.2 on the left and maybe up to 5.0 on the right. Caster is more of a ballpark thing. As long as it is in the 4 - 5 degree range, and your cross caster is -0.7 to -1 degree you should be good. Like 3.7 left, 4.5 right would be ok too, for example. Some manufactures have their spec range pretty wide, usually 2.5 to 5.5. There is alot of wiggle room. Every truck seems to handle differently, so what works for one truck may not be perfect for another. Talking with the customer to see how it handles is important in determining if it needs more or not. Unless your truck is city delivery truck that makes a lot tight turns frequently, caster does not wear tires. Caster is a handling thing. Extreme caster makes the wheels tilt as you turn them. The tighter the wheel is cut the more pressure is on the shoulder of the tread. But in reality, how often or for how long are the wheels turned all the way to one side or the other? Since this time in relation total drive time is so small, caster is considered to be not a tire wear factor. As for handling, extreme caster will over stress the p/s. The steering wheel will return to center after a turn very quickly and you will feel every bump in the road through the steering wheel. Low caster will cause wandering on the highway and lack of steering wheel return to center after a turn.

 

It seems they are doing a lot of axle bending in Australia to "australianise" axles made for right hand traffic. http://www.truckalign.com.au/

US origin company http://www.beeline-co.com/scripts/products_catSub.asp?Cat_Top=Heavy+Duty&Cat_Sub=Axle+Correction

Too bad we don't have any company in Europe that does that, lot's of trucks need axle alignment and correction, they are behaving very badly, especially Volvos.

 

EBS - electronic brake system (brake by wire, in use from '96)
ESP - electronic stabilize program - needs additional yaw/lateral acceleration sensor (FDR in German version) and steering wheel angle senor. This system prevents jackknifing well!!!

RSS - roll stability system. Calculates center of gravity and in case of danger of rolling over apply brakes to prevent rolling. May work with ECAS (electronically controlled air suspention)

 

is that reason why mercedes eats front tires?

 

Usually it's just wrong toe-settings. Too much toe-in eats outside of tyres but is usually good to drive, toe-out eats insides and is very snaky to drive.

 

The real deal is:
Correct camber settings in relation to the road surface is the foundation of a proper alignment and skipping this step and attempting to somehow compensate through other adjustments is not the solution.
There are many independent shops that will bend your axle for $200-$300 bucks (including alignment) you just need to seek them out.
Axle manufacturers preach "do not bend our axles" Why? It costs them lots of money for field reps to investigate problems associated from inexperienced people doing the work incorrectly. It opens them up to warranty claims in which parts and labor eat on their profit margin.
The training schools say no bending of axles! Why? It takes alot of skill and judgement to be done safely and must be closely supervised when newbies are involved. One class clown makes the wrong move and the school is "down for the count". The insurance companies say no! We cannot write this risk!
So, all these folks tie our hands so that we can no longer do what needs to be done!
Why? The easy money could be taken away from them in a heartbeat!
I say when it comes to alignment the old way can't be beat!
The trucking industry is a dangerous place at any level when inexperienced people are working among us, so education and training is the key!
Axle manufacturers offer no alternative to bending their axles in the truck but still insist we don't do it!
Then maybe they should by us our steer tires!