Hot Rods dropped axel/ tire wear

1/4" difference on the camber, is not good


Measure the Toe while you are at it.

 

the car is hauled on a trailer........it just a sbc around 300 hp, no wheel stands......

 

toe is 3/16.......also the frame is 2' BY 3" 1/4 " tubing, don't think it flexes

 

3/16" sounds a little generous. What did Ford specify originally ??

 

I'd have to believe that the gent who dropped the axle didn't "set" the camber when or after he dropped it.

As some of the guys said previously you will have to take it to a shop that works on vehicles with I beam axles on a regular basis and has the equipment and knowledge to sck et the camber. The normal method is to place a 20 to 50 ton jack in the desired spot under the axle and chain the axle to the framework of the front end rack and tweak the axle to get the correct camber. Knowing where to put the jack and where to put the chains is where the knowledge and skill come in. The other option might be as someone suggested and pull the axle off after the racing season and ship it to Sid's shop where they do set the camber on every axle they do after they drop them and they can correct other issues that might affect alignment.

 

I still think something other than camber is out of whack. In 20 miles of driving, you don't wear tires one sided to the extent you have described. In fact some old time lineup guys used to set front ends with more positive camber (wheel in @ top) on p***enger side to allow for the high crown in the 2 lane roads of the past. Just tilting the tire a little more ain't gonna wear tires that fast. Something is dragging those front tires sideways.
Bobby, what did you use for a reference point on the rear axle when you measured to check for square? When we measured BGII and squared it up before it's maiden run we used the following procedure;
#1- jacked up and put both axles on stands with load on axles
#2- removed rear tires and wheels, and with precision level rotated hubs/.drums till top 2 lug studs were EXACTLY level, which placed bottom stud exactly on bottom.
#3- strung plumb bob line from bottom stub while line was pushed against hub/drum surface where wheel is mounted, and marked on floor with chalk where plumb bob point indicated
#4-plumbed from spring center bolt hole in front crossmember and marked floor for front center point
#5= measured for square and adjusted as required.
Then you have to do the front axle the same, but you must completely disregard the spindles and ***ociated, such as hubs and drums, ideal way to check front axle is from king pin holes. But however you pick a point on the 2 sides, it must be the same, and on the axle itself, not the spindles. I know this is A PITA, but if the axles aren't square and tracking together, I don't give a **** how you align the wheels it ain't gonna be right and you'll always have problems.
BTW, are you sure the frame itself is square?
On another subject briefly, looks like I gotta do some finagling to make that loop work thanks to my angled ladder bars.

 

Try 1/16" toe in.

 

If the wear was on inside of both tires, or the outside of both tires, I could agree to play with toe, but one's wearing inside and the other outside. Something ain't square to wear enough to see it in only 20 or so miles.

On edit: Bobby have you checked cir***ference of both rear tires? are they equal? Rear gears: open, locker, limited slip, or spool?

 

I only drove the car on the strip and a couple parades......20 miles is a guess it could be more, maybe 50, 60, but the problem is noticeable on the tires.....rear gear is a factory posi out of a truck , ill jack it up and get someone to help me do the measuring

 

I'm not doubting your mileage, but that has GOT to be some kind of record. It's damn near impossible to notice wear after double or even triple what you figure the mileage could be. Have you tried another set of tires? I'd also check every piece up front. pay extra attention to the tie rod. A slight bend, so slight you may have missed it, would cause crazy wear.

 

thanks everybody, its a new tie rod just put it on about a month ago.......gonna start checking all these good ideas tomorrow.....

 

Well, good luck with it.

 

If the front end were out of square - in order for the car to go straight one spindle would be rotated on its king pin axis one direction and the other wheel rotated the other. That certainly will scrub the tires and quick.

If you have a spare or complete front end ***embly on tires laying around try and roll it across the floor in a straight line with the wheels ****ed

 

Do you have the tie rod in front of the axle? Is the ackerman set correctly? Do you have 3/16 toe in or out?

 

tie rod is behind the axel, 3/16 toe in, ackerman??

 

Ackerman ain't gonna have much effect on a mostly drag strip driven hot rod, as last time I looked those quarter miles are driven in a straight line.

 

I don't believe either Ackerman or toe are the issue here. Something is causing the front end to be "pushed" to the right. A tight posi and a smaller diameter/underinflated tire on the right side would do this, given that all your alignment measurements end up proving things within spec.

 

drivers side spindle moves up and down on king pin 1/16

 

You didn't put enough shims in.

 

What shims

1/16 will be 6 or more if its nice smooth movement up and down on the king pin. 20-60 miles probably wouldn't do much damage to the pins. But since it needs to come apart for the shims, probably wouldn't be a bad idea to have a fresh king pin set and bushings that includes 4 shims and bearings there on hand as well as a couple shim packs. Run you about 65.00 with shipping.

The vertical slop still wouldn't wear the tires like that

 

thanks...........

 

View attachment 2715362

If you have one of these, put some tires on it, **** the wheels just a little and try to make it roll straight across the floor. Then imagine forcing it straight across the floor as the tires scrub

 

Yes, yes and on different edges too, as camber will go more negative on one side, & more positive on the other, when this happens..

 

just found the problem with the spindle moving up and down on the king pin, pulled spindle and king pin off axle and found that the draw pin had sheared off some of the wedge when installed and wasn't locking the king pin from moving, got another draw pin and put it all back, just like new, ill tear it down this winter and rebuild front end and also have the axle checked, thanks for the help, still need to measure for square.....

 

That is the first thing!
But also check for caster being different from left to right.
Caster combined with Toe [in or out] will induce some camber change.
All it would take is one violent hit [pothole] to twist a dropped axle rearward

 

The problem you described earlier wouldn't be caused by what you describe in this post.

The distance between the ears on the spindle needs to be shimmed very close to the same width of the axle plus the bearing. If its shimmed properly, you can remove the kingpin and there would be no vertical movement of the spindle.

The king pin lock bolt has 3 functions.
1 it keeps the king pin from rotating.
2 it keeps the king pin in the axle
3 it removes any of the necessary clearance between the pin and the hole in the axle by wedging it tight to the inside eliminating and movement between the pin and the axle. In essence making the pin and axle one.

 

Unless the axle hole's so loose from running around with a bad wedge that the kingpin is sloppin' sideways.

 

I can't get my hands on it to see, i cant read minds & I don't guess- so that means all I can go off of what's typed here. "Vertical movement of the spindle on the king pin" is whats stated and theres only one way to get that. the lock pin isn't part of that, plain and simple.

Not to be a **** but there's no ifs ands or buts, no excepts, no forgots - nothing. Shimmed properly you can remove the kingpin, throw it outside and there is no vertical movement.

 

Look for a Bear alignment center. If you can find one, they usually have the equipment and someone old enough to be able to help you.

 

No sweat bud. I don't doubt what you're saying about vertical movement.
Vertical movement alone shouldn't cause the tire wear described: it's a side issue.
But if the wedge (lock pin) is bad, the kingpin will move sideways.
And he says it's bad.