Alignment specs.

[Hammond68]

I just got my truck aligned. Now it pulls to the left. The tech said the machine wouldn't show camber for some unknown reason. They also claim alignment specs are the same from 1947 to 1998. I find this kind of hard to swallow but I'm not an alignment tech so I don't know. I'll attach a picture of the alignment sheet.

[Wrenchbender Ret]

You have over 2 degrees of difference in the caster in the front wheels. That will make it pull to the left. I don't have the specs handy but they should be near the same.
George

[Bigdav160]

The specifications certainly are not the same from 1947 to 1998. They ran way less caster and more positive toe when bias tires were the norm. Factory installation of radial tires led to the change of specifications to run more caster and not as much positive toe

But in your case, 1 degree of cross camber (pulls to the most positive side) and 2+ degrees of cross caster (pulls to the most negative) guarantees it will want to go left.

Assuming you are running radial tires I would cut the toe in half

[Hammond68]

I got it done at Firestone. So I'll have to take it to a different location and have them redo it. I told the tech to set it to 87 specs. 72 came with bias tires. 87 with radials. I read on here 87 is the way to go. The fool still set it to 72. He thought 47 to 98 were all the same because that is the range of years in their program. In the picture It still says 72 after the other years.
I wouldn't knock Firestone to hard. I just ran into an idiot at one location. Its guaranteed so they'll make it right.

[HO455]

Not to mention that whole straight axle versus independent front suspension thing.
I wonder if he can set the camber on my 51 GMC?

[Rooster73]

Well, here I go again. Yes. a shop could use later square body specs, but if they can't tell when a caster split is wrong without a screen showing bad and good colors, DAMNIT. If a shop doesn't put in a specific vehicle and just sets the screen under custom specs, then they know their stuff on our trucks. 3.5 or greater caster,as equal as they can, if not only slightly less on left side, for the crown of the road. And yes. Fatter tires like more caster. Wish you were closer, I would align it for you. These stories just blow my mind. It should be as basic and easy as drum brakes, but that just scares the hell out of some "techs".

[68 P.O.S.]

Read over the following thread. It has a lot of great info. http://67-72chevytrucks.com/vboard/s...d.php?t=582187

[Hammond68]

Is there a set of numbers I can give them for settings. I don't really want to spend hours upon hours learning about alignments when I have to pay to have it done anyhow. It's not laziness,its just I paid 110 to have the job done. There's a whole lot of other places I'd rather spend time researching rather than something I cant do myself anyhow.
I'm running 255/70/15 tires on a 1972 stock 2wd c10. If someone already knows this info I'd greatly appreciate it.

[68 P.O.S.]

Yes, post 23 of that thread

[Hammond68]

Thanks 68pos. I've got -1 to -1.5 on camber. +3 to +5 on caster. 1/16th toe in on each side for 1/8th total. Though the in is shown in degrees.

[RustyPile]

Originally Posted by Hammond68

Thanks 68pos. I've got -1 to -1.5 on camber. +3 to +5 on caster. 1/16th toe in on each side for 1/8th total. Though the in is shown in degrees.

If I'm reading your printout correctly, no you don't.. Left side is .3 and right side is 2.8Not even close.. 2.5' difference will definitely cause a pull.. Many years ago I worked as a shop foreman at a Firestone store.. I dealt with moronic mechanics on a daily basis.. Salary caps wouldn't allow the hiring of qualified/certified people.. It seems "times haven't changed"...

[Hammond68]

Sorry 68. I wasn't clear. I meant what I got from that post is these would be good numbers to go with. Is there a degree for the 1/16 toe in? Wouldn't want the tech to have to think. It may be too much for them.

[68 P.O.S.]

Try this https://robrobinette.com/ConvertToeInchesToDegrees.htm