The Stovebolt Site Forums The Shop Area Driveline Positive camber problem

I haven't found many threads on this topic. I have what I think is pretty bad positive camber. In the picture the gap between the straight edge and axle is about 3/16 inches. Could this be the problem or elsewhere? New kingpins, no wobble, nice and tight. Is there a way of finding where the axle is bent?

How does the truck drive and steer? Maybe that flange is just bent from hitting a rock or something. The top of the axle looks straight.

What problem are you referring to?

That could indeed produce a bad camber angle, but positive camber (top of wheels tilted out) is what you want. Did you have the angles checked, either at an alignment shop or with a magnetic angle gauge? As long as the bearings are properly adjusted, you can measure camber angle on the face of the hub after removing the grease cap. You should also measure the kingpin inclination (at the machined surface at either top or bottom of the spindle where the kingpin goes thru. The specs for a Chevy 1/2 ton or 3/4 ton are: Camber - 1 degree +/- 1/2 degree and Kingpin inclination: 7 deg 10 min +/- 1 min of angle. Should be the same for your GMC.

If the difference between kingpin camber angles isn't the same on both sides, then a spindle is bent and would have to be replaced. Bending the axle will change both camber and kingpin inclination. Check first before deciding the axle is bent.

Are you having issues with wheel alignment while driving?

Another possible reason for too much positive camber is the attitude of the truck, if the rear axle center line is higher than the front spindle (axle) center line, you would have more camber and less caster than spec'd. I have larger diameter tires on the rear than on the front and it tilts the front axle and king pin inclination resulting in too much camber and not enough caster. Caster shims can bring it back to spec if that is the cause.

Yes, but a rake in truck stance shouldn't affect camber much at all. With the spec of 1 degree positive camber and 1/16" toe in, raising the rear axle would make a camber change barely measurable.

Pauld needs to take some measurements first.

Also, the toe is way in and I can't pull it in enough, the tie rod bottoms out on the ends, like I need to shorten the rod.

I will process this information and report back, it'll take me a few days.

If the toe-in is way off, check the front face of the axle, it might have hit something so hard it bent it towards the rear of the truck, that wold make for a toe-in so bad you could not be adjust it outward.

jacked up from underneath and bent possibly

There is an app you can download for a cell phone that will do a pretty decent job of showing angles. Normally I dismiss these techie things but as I said this one is actually okay if you are okay to have measurements in 1 degree increments only. It goes under the clever name of "Angle Finder" and is free. You can pay for a version that gives you decimal precision, but I haven't found it necessary. There is a setting in mine that will show fractional angles, also. I'd download it and then go out and start taking measurements for caster and camber...this is going to give us a good idea of what you have on both sides. It isn't hard and even if you have one of those cheapo plastic magnetic angle finders you can see what is happening. Your front axle obviously suffered some sort of a blow in the past, but let's get some measurements first. As for your tie rod, if your axle was hit hard enough in the front to cause the tie rod to bottom out, you would be able to see that very clearly by sliding under the axle and looking up at it or by looking at the back side. Most of the time, the axle is hit in the front when somebody is driving along and hits a large rock or curb or something. If it was hit that hard generally speaking there is a good chance it is ruined. Now on the other hand if some prior owner hit that rock and ruined the tie rod at the same time (almost impossible to avoid this) then it is very likely a tie rod from something else was used to repair things and it was a bit too long. I've seen this happen before. I've also seen folks cut a tie rod and then weld a square iron piece on to shorten it to the correct length. And I should mention somebody welded a square piece of iron on my tie rod at some point in time...I suppose to strengthen it but that's just a guess. For now let's put on our detective hats and get some data.

I purchased an inexpensive angle finder from Harbor freight, it looks like the only way to find the correct angle on the Kingpin is to remove the backing plate from the axle, is that the way to do it?

Find an old school alignment shop with a magnetic caster/camber gauge. Like the old Sun Electric Co. slogan- - - -"We test- - - - - -not guess!" Or, you could just remove a wheel and use your angle finder on the wheel mounting surface. Just make sure the distance from the bottom of the spindle to the floor is the same as when the truck is sitting on the tires. Or, just buy this one:

www.ebay.com/itm/376886491557?


Jerry

The machined surface on the top and bottom of the kingpin bores is a little restricted by the backing plates, but if you had a straight steel bar you could hold that on the flat surface there and use your magnetic angle finder.

[on edit] Added picture.

I just ordered that magnetic angle finder. The one I bought from Harbor Freight won't work, I was in a hurry when I bought it. I'll report back after I get that tool. Thank you

I downloaded a angle finder app and found that on the one setting it is one degree on both sides and when I had the decimal setting it showed 1.4 approximately on both sides. Truck front end sitting on jack stands, equal distance from floor to spindle. I'm attaching a photo of the tires which shows the wear on the outside and none on the inside. This is with only 10 miles on them from the maiden voyage of this truck. The tires were screaming when I got it up to 25 miles an hour. I assumed camber was off because of the way the tires were wearing and the way the tires tilted out at the top so much. The toe is still out about 3/4 inches with tie rod bottomed out in the ends. Looks like I'll have to cut and shorten the rod. Also I DID find the wheel bearings needed to be snugged down a little on both sides.

The toe-out is your problem. Check to see if the axle is bent in the middle with a long carpenter's level or some other type of straight edge. That kind of bend can be corrected with a heavy chain and a big hydraulic bottle jack. Wrap the chain around the spring seats in a bowstring shape, and use the jack to push against the center of the axle, from the front or rear.
Jerry

It looks like the passenger side is bent towards the front end by about 3/8 of an inch, but that would mean I should have even more room with the tie rod instead of it being bottomed out.

It does have a slight bow in the middle from side to side as shown in the picture in a previous post

Don't assume the tie-rods or rod is correct for the truck. 3/4" toe adjustment is huge, surprised it stayed on the road. Post up a picture of the tie-rods being used and a measurement of overall length so we can figure out where the problem is.

Are you saying the front of the tires are toed OUT or toed IN. Outside edge wear of both tires will be toed IN at front and won't go down the road with fighting at the wheel to keep it straight. A toe out at front tends to drag one tire, not both, and the wear is more towards the inside edge.

That looks like a pretty big tire, so they may look angled more due to the hight. The machined surface at the outer wheel bearing on the hub is a good place to check for camber, just pull the dust cap off and attach your magnetic angle finder. But remember, with the toe adjustment off, so will be the camber since the tires are not straight ahead. The camber changes as the tire turns left or right.

Looks like it was a handful to drive
Is your toe measurement taken with the truck on the ground and rolled forward and back to untension the tire? And a tape measure reading taken?
Even with toe plates you have to watch the bulge at the bottom of the tire is not influencing anything
Even recheck the camber with tires on/truck on the ground to see if there is a difference fully weighted"…….
I’m my shop I have leveled plywood spacers and painted locations so I know the truck sits on level ground.

Toe adjustment is always made with the vehicle is in as driven position, full weight in the tires, rolled forward to take out slack in steering system, and on level ground.

Okay, I put the wheels back on the truck rolled it back and forth, got under there and still have 3/4 inch difference on the toe in. So the wheels are closer in the front than in the back of the wheels, measurements taken off of rims, not rubber.

The tie rod is bottomed out on both ends with 39 3/8 inches showing between the tie rod ends.

Tire size is 235/75R 15.

Used the 'angle finder' app on phone, bearing caps removed, found -1 camber on both sides on hubs.

And yes it felt really bad going down the road even though it was the first time I ever drove the thing not knowing what to expect.

Since camber appears to be equal, should I not be concerned about that for now and focus on the toe?

I think shortening tie rod by 1 inch will give me the room to make adjustments.

Thanks for all this input
Paul

Good work, -1 camber on both sides? We all wish for that…
Have you taken the rod ends off and scrubbed the inside to be sure they cant go further before trimming?
Might want to creep up on the shortening dimension, want as much thread purchase as possible into those clamp style rod ends, strength is the deep part.
Chuck

As long as you are at it ...

While the tie rod is off find a nut large enough to slip over the tie rod and weld it on. Use the nut and an open end wrench to turn the rod while adjusting the toe-in instead of grabbing the tie rod with a pair of pliers or a pipe wrench. That way you won't be messing up the paint and leaving teeth marks on the rod.

Not my original idea. It came to me from Jack Gifford, who has a great looking 59 GMC.

Yes, already had the tie rod off, checked threads, inside and out, all good. I'm thinking of taking 1/2 inch of both ends and not out of the middle and welding. I will thread a nut on, cut it and use the nut to help clean the threads.

Does that truck have power steering?

If not, those wide tires are going to make driving unpleasant.

No power steering Otto, I wanted to try to keep the truck as original as possible. The radial tires are surprisingly easy to turn. Wine festival this weekend, I'll get back to the truck next week

Looks like 25/32-16 is the tie rod thread. Doubt if my local Ace store will have that.

Here is the rod for a 1940-54 truck, https://www.chevsofthe40s.com/detai...od_Rod_Only_Fits_4054_12_and_34_Ton.html 43-5/8" long

This one from Jim Carters, https://oldchevytrucks.com/me437.html 43-1/4" long

'29-'54 parts manual list '32-'55 all 43-3/16" long 3/4-16 thread Left and Right

6.103 from the parts manual for steering arms, https://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0524.htm
6.008 from the parts manual for beam axles, https://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0522.htm
6.233 from the parts manual for tie-rod fittings, ( outer housing ) https://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0522.htm

Careful cutting the left hand threads off, a right hand thread die is much cheaper to purchase if you need to add more threads to the bar, you could probably buy a whole new bar and then some for the price of a 3/4-16 left hand thread die.

Could one of the steering arms be bent? Maybe someone with the same year of truck could measure the arms, what year is your truck?

It's a 52 GMC but I also used parts from a 50 Chevy Chassis and I'm not sure what parts I used for what. Seemed like a good idea at the time (4 yrs ago). I'll have to remove the tie rod and see what the length is. I may just cut it from the middle weld it and reinforce it with a piece of angle. I can always dump more $ into it and buy new parts.

I cant recommend centercut & welding on a critical steering component, shorten the ends, your pictures show you have the threads.

My '37 has the same type of tie-rod ends, still factory ones but unsure of the yea, the axle is not a '37. It measures 48-3/4" end to end and really close to you 38-3/4" between the tie-rod housings, the tape measure kept falling off so not 100% accurate. Tie-rod housings are 5" length. Mine only has a maybe three threads showing, way less than yours.

I would look close at the steering arms to make sure one isn't bent or installed wrong if that's even possible. In the straight ahead position, the drag-link end should be dead center over the axle, or I should say, the ball stud hole in the steering arm for the drag-link is dead center over the axle. This is pretty much a standard on all straight axles still today. It insures equal turning left and right. Start with that and see if the drivers tire is now straight head, and passenger is toe-in a lot.

This is the position mine sits at right now. I don't see how that could have been bent without destroying the rest of the front end but who knows.

My guess is both ends of that arm are bent, bet it steers more one way than the other. Make sure there is no funny spacer behind that arm keeping it from going in the right place.

Trucks had a hard life back when these were new. Mine came from a plumbing / heating company, all four fenders were welded on and the leaf springs had 1/2 the thickness worn off from the leaf below it rubbing on it, the whole stack on each corner was worn out!

Yep, hard life

Guess again on that die, Joe- - - - -Evil Bay is full of them!

www.ebay.com/itm/285453210521?

Jerry

Jerry: Why is a die adjustable?

I must have been looking at USA made dies, they were expensive back when I needed one. The die is adjustable so you can fine tune the thread size or make up for a poorly made die that's not quite right, it's not a lot of adjustment.

Update. Well I haven't done anything else to the front end of that truck except for try to bring the toe in as much as possible bottoming out the ends. Still have a little toe out in the front but just for grins I took it for a nice little drive into town. It ran straight and felt normal unlike the fighting I had to do with it before I worked on it. So I think I'm just going to leave it go for now and enjoyed the ride. Also, the tire wear looked even across the tires. Thanks for all you guys help

If you are close, I would cut a few threads off each end and bring it into spec, it will drive much better with toe-in. Toe-out is going to make for tire wear and steering wheel fight. With toe-in, all the stress on the steering linkage will pull the tires out to almost zero toe adjustment, with a toe-out, it will go even farther out of adjustment.

Too much toe-in will wear the tires as much as too much toe-out. The truck will handle ok with toe-in but reduced economy and high tire wear.