Camber, caster, toe-in, toe-out ???

[hsdropout]

Hard to tell by photo but my left front wheel is leaning out on top about 1/2 inch. Noticed it when I took body off.

Anybody know what might be the cause for this?

I haven't taken the wheel assembly apart yet, hoping it's a combination of bad bearings, kingpin and some adjustment. I did a search but could not find much that I could understand relating to this.

[mr48chev]

If that is the tire that has been running on the front for a while it looks like the truck has too much positive camber.

Look at the outside edge as compared to the inside edge and it looks like the weight of the truck has been riding on that outside edge rather than the whole tread of the tire. It looks like the outside edge is rounded off while the inside edge still has a defined edge/corner on it.

Excessive toe in or out usually causes the tire to look and feel like it has been drug sideways down the road and the tread will have a feathered appearance and feel to it if you rub your fingers across it sideways back and forth.

I won't say it can't happen but I have never seen caster even if it is excessive to cause tire wear. Usually if the caster isn't right the rig doesn't want to track right going down the road and if it is excessive steering can be harder than normal or in extreme cases you get a bit of tire flop but I've only seen that on dragsters.

As far as correcting the camber, after you have the truck back together with the front axle pieces all rebuilt/replaced and in top shape you will have to take it to a shop that is setup to adjust the axle. That is usually a shop that specializes in big trucks and rv's anymore as the tires shops with the fancy computer alignment machines usually aren't set up to do it. It involves bending the axle by chaining it to the alignment rack and using a jack in the right spot. I wouldn't put a bunch of paint or powder coating on it before i took it to the alignment shop though as it would most likely get scratched up. With that it may be put it together, have it corrected, take it apart and paint it and put it back together. That is if you want to paint or powdercoat it up real nice. If you spray bomb it then just spray bomb it after they get done again.

[raycow]

It is normal for the wheel to be slightly out at the top. The service manual will have the specification for camber. AFAIK, the normal way to change it on these trucks is by bending the axle. Alignment shops that work on big trucks should be able to do this.

Ray

[hsdropout]

Wow....that would be bad news.....bent axle?

Seems it would take quite a force to bend one of these.
Possibly hit from bottom? that would cause it to lean out right?

I'll look for any major scars on the bottom of left side axle.

[mr48chev]

Not bent as in "bent" but knocked out enough so that it needs to be reset. Not a real big deal if you take it to the right shop.

I'd call Sacramento Spring and see if they do it or who they suggest if you don't know of anyone who does I beams in that area.

[hsdropout]

Yea, good tip Mr. 48.........Thanks.
I checked Sacramento Spring website.....
sounds like a "BFH" would do it, if not they use a bigger "BFH".

The right shop ought to be able to perform precise measurement and make it right.

I'll check around.

[steve53]

wait till you have the truck finished before you align it. you need all the weight that is going to be on the frame to make sure it doesnt change the camber over sitting there with just the frame holding it on the ground.

[T Hilde]

Generally this is not a problem with a straight axle. When I worked in the alignment shop we would do it on repairables (4X4 w/straight axles) and never had a problem.

Originally Posted by steve53

wait till you have the truck finished before you align it. you need all the weight that is going to be on the frame to make sure it doesnt change the camber over sitting there with just the frame holding it on the ground.

[hsdropout]

Thanks for the input.
I am going to proceed with new bearings, kingpins, install the new mono-leafs and new shocks. Mount up the motor & tranny & pretty much everything else and not worry too much about the axle thing for now.
Prior to noticing the "lean" I decided to go out on a limb and popped on a "No Limit Engineering" rack & pinion P/S kit. Fits up to the straight axle. Curious if anyone has used this kit? A little pricey but I like the idea of the staight axle with P/S. I hope it doesn't end up being a piece of junk.

[Yezzi]

how's that p/s kit from no limit?

Originally Posted by hsdropout

Thanks for the input.
I am going to proceed with new bearings, kingpins, install the new mono-leafs and new shocks. Mount up the motor & tranny & pretty much everything else and not worry too much about the axle thing for now.
Prior to noticing the "lean" I decided to go out on a limb and popped on a "No Limit Engineering" rack & pinion P/S kit. Fits up to the straight axle. Curious if anyone has used this kit? A little pricey but I like the idea of the staight axle with P/S. I hope it doesn't end up being a piece of junk.

[mr48chev]

Rob from No Limit Posts on the 67/72 Forum pretty often so you should be able to PM him if you have any questions on the steering.

Having driven my truck with the stock steering for at least 100,000 miles and another 100,000 with a subframe and power steering under it I can see the desire for power steering that works.

[DrKrankenstein]

Digging up old thread but new problem for me.

After installing 3" dropped axle, my camber is also positive, very similar to picture in first post but mine might not be as badly toed in.

After what I am reading the only way to correct it bend axle? I am down in the So.Cal area so I will need to see which shops align these older trucks.

[whitedog76]

Here you go.

http://chevy.oldcarmanualproject.com...4ctsm0312.html

[DrKrankenstein]

Thank you for that whitedog

I have to say I am not too impressed with the dropped axle we installed, I would think this is something that would have already corrected when they sell these.
This is now the third and separate issue we have had with installing this axle.

[MiraclePieCo]

If your straight-axle truck is stripped down you should EXPECT to see positive camber.

If you don't have the full weight of the engine, transmission and front clip on your truck, straight axle vehicles will exhibit excessive camber (top of the wheel points outward). Axles are designed for a specific weight and when properly loaded they will deflect slightly bringing the camber into specs.

[1project2many]

MiraclePieCo. I fully disagree about camber. The weight applied to the chassis has little bearing on camber angle with a solid front axle. Camber is a function of kingpin inclination angle and included angle in the spindle.

Independent suspension vehicles will definitely exhibit camber change with a change in chassis height and vehicle loading. I believe one of the worst examples of this is Ford's twin-I beam suspension. On a vehicle which does not carry a consistent load there is often no setting that provides good tire wear.

DrKrankenstein, was your axle shipped with spindles? Have you checked the kingpin angle against mfgr specs? If the kingpin angle is correct but the camber is not, you may need a new spindle.

[DrKrankenstein]

Originally Posted by 1project2many

MiraclePieCo. I fully disagree about camber. The weight applied to the chassis has little bearing on camber angle with a solid front axle. Camber is a function of kingpin inclination angle and included angle in the spindle.

Independent suspension vehicles will definitely exhibit camber change with a change in chassis height and vehicle loading. I believe one of the worst examples of this is Ford's twin-I beam suspension. On a vehicle which does not carry a consistent load there is often no setting that provides good tire wear.

DrKrankenstein, was your axle shipped with spindles? Have you checked the kingpin angle against mfgr specs? If the kingpin angle is correct but the camber is not, you may need a new spindle.

Yes axle was received with mounted spindles in place for me ready to install. No modifications necessary, supposedly.

[dsraven]

read post 13, it explains it right from the factory manual. one affects the other. I wouldn't, personally, spend money on any of it before getting the parts checked.

[MiraclePieCo]

Originally Posted by 1project2many

MiraclePieCo. I fully disagree about camber. The weight applied to the chassis has little bearing on camber angle with a solid front axle. Camber is a function of kingpin inclination angle and included angle in the spindle.

I've built numerous cars with straight axles. and have literally WATCHED camber change when they were loaded to weight. Straight axles will flex noticeably between the mounting pad and the kingpin boss - especially deep drop axles. You can actually watch them flex and the camber angle change as you drop the engine in. My first experience with this phenomenon was with a '34 Ford pickup I built with a 6" drop axle. During mockup I was horrified at the outward inclination of the tires and feared I'd have to have the axle re-bent. But as weight was added during construction, the camber angle came back to neutral.

Below is a simplified illustration of the forces involved.

[mr48chev]

They will change after they are loaded. I would not change anything except getting the toe in close until I had the truck done to the point where all the weight was on it and it had been driven around the block.
If you bought a dropped axle from Nostalgia Sid it should be set on the money for what an I beam axle should be set at. If it is the Speedway junk all bets are off or if it is an old used one you don't know what it has been through.
All of the older skinny tires rigs before about 1980 ran positive camber. Cadillac Deville was the only rig that called for negative and that was 1/4 neg on the passenger side tire. Most of those early Mustangs called for 1 degree positive. Neg camber didn't come into play until later when cars like my BMW 528I showed up with it so they could cut the corners better. That was a whole redesigned setup from the older rigs though. Simply meaning because your late model performance car that you drive daily has negative camber and the past three cars before that did there is nothing wrong with an I beam truck having positive camber as long as it isn't excessive.

Adjusting camber on an I beam or "straight" axle takes setting it up on the alignment rack and actually chaining it or using designed hooks to tie it to the beam on the rack and then applying pressure with a bottle jack in the right place to move the end of the axle where you need it to be. It's a long way from rocket science but one has to know what the heck he is doing so as not to screw it up.

Again, don't worry about it until the truck is all together and derivable. Outside of sending it to Sid to be checked and corrected there really isn't much one can do with it beforehand.

Some vendors sell an inexpensive caster/camber gauge on Ebay that might help in the preliminary setup and checkup on any build and for 15 bucks they aren't that bad. I haven't compared the one I bought against my SnaoOn Caster/camber gauge yet but it looks like a viable thing to get close with . https://www.ebay.com/sch/i.html?_fro...gauge&_sacat=0

[1project2many]

I've built numerous cars with straight axles. and have literally WATCHED camber change when they were loaded to weight.

They will change after they are loaded.

Interesting. The only time I've seen this happen is with an old Ford axle that had been drilled for weight reduction. We set up the front end with the engine out and noticed something wasn't right after the car was fully built. Realigning the front end was easy, but the axle failed once the car was on the track. In that case the drilling process appeared to weaken the axle.

[MARTINSR]

Originally Posted by 1project2many

MiraclePieCo. I fully disagree about camber. The weight applied to the chassis has little bearing on camber angle with a solid front axle. Camber is a function of kingpin inclination angle and included angle in the spindle.

Independent suspension vehicles will definitely exhibit camber change with a change in chassis height and vehicle loading. I believe one of the worst examples of this is Ford's twin-I beam suspension. On a vehicle which does not carry a consistent load there is often no setting that provides good tire wear.

DrKrankenstein, was your axle shipped with spindles? Have you checked the kingpin angle against mfgr specs? If the kingpin angle is correct but the camber is not, you may need a new spindle.

I am very impressed, I have met very, very few guys who knew what "included angle" is. I do have to disagree though that the full weight of the truck will effect the camber, not much, but it does effect it.

Brian