Hot Rods Cast Front Axle & Tire Wear

We've rotated radials any direction we wanted, removed them, swapped them around on the rim and reinstalled with no problems.

I'd really like to know what the camber reading are on that axle though.

Tire scrub on the corners are pretty common on a straight axle, it's caster that causes corner scrub 90% of the time. Especially if you do alot of town driving.

....

 

What @Mr48chev said.
The “requirement” to rotate radial tires in the same direction comes from the fact that on the driven axle the torque input into the belt package would cause a minute cir***ferential stretch of the belt package against the radial body plies, both of which were polyester for it’s ride properties. This “ set” was acceptable as long as the rotation stayed the same. When it was reversed, the same torque application would push against the belt in the opposite direction, loosening the bond between the belts and body, and the belt package would separate and come loose. OOPS!
Advancement in manufacturing procedures and components led to less frequency of this, but there is no way in actual usage to foresee or predict it happening. Therefore the “requirement” to lessen the possibility.

BUT, the slippage or separation of the belt package can lead to all sorts of weird wear patterns. Normal belt edge wear on radials is a slight step down on both of the outer ribs, coming from the tread squirming on the edge continuously as the tire rotates, through its footprint. The belt package cannot come all the way to the tread’s edge, being flat against the curved radius of the body plies.

Could Gary’s problem be an issue with what is called “belt edge separation” all the way around the tire? Unlikely, but If there is NO scuff on the tire, and the camber is NOT excessive, it COULD be. But those unknowns remain so, and so does the mystery.

Cl*** dismissed. Carry on.

 

I'm wondering if the Caster change caused by using hairpins might be the problem. It changes as the suspension moves and it is working from shorter (and different) pivot points than the original Henry design. Shorter pivoting distance causes more Caster change as it moves. It may be that the p***enger side hairpin moves more often than the driver side....since they create a variable Caster as they operate.
That would possibly be a consideration.



Read what is said below and notice that they mention unequal Caster on some aftermarket axles.



"A solid type axle would be thought to have equal Caster on both ends, but this is not always the case"



Could the shock absorber on the p***enger side be contributing to this as well?


So, here is some food for thought anyway.........

 

I built 100's of ch***is with hairpins in my 40+ years in the ch***is business with no noticeable problems. The last 20 years I only did a couple 4 bars. Mostly because I did not promote them.

 

@hotrodA , that's why I'd like to see the tires and know the camber/caster readings.
Have more info to make a WAG on.

@ekimneirbo , yep I've seen that a lot over the years. Usually cheap cast axles and old oem dropped axles with lots of miles. On cheap axles its quality control or lack of and on old axles its usually been thru a hard life of someone hitting one of the tires hard either thru a wreck or being hit hard against a solid object, pole/curb/ off in a ditch etc. Shock absorber is definitely a avenue to check too.. that's why I prefer NON-gas charged shocks on light cars, it allows to suspension to react softer to road conditions.

@krylon32 , lots of hairpins out there but again people either not understanding or too many backyard u-tube video's that doesn't explain angles, suspension travel, caster etc when building their suspension.

Again experience thru the years of seeing people build their own suspension, front or rear, and not taking things like caster, track, etc into account and when they come into the shop with problems and you try to explain it to them and they look like a dear caught in the headlights you know they have no idea what your taking about...

That's one area you have the advantage over me, you get to build a lot of your own stuff, me I get to see most of mine after the customer has tried to build his own stuff with no prior experience...

Just had a older guy come into the shop this last week asking questions about his 47 chevy g***er build. Said he has had numerous guys tell him to build his rear suspension around his springs, I told him NO, build the springs around your suspension. As in set frame height, set axle center height, build ladder bars and brackets to that then build springs to keep everything at that height and angle.

Said he was told not to do anything UNTIL he had springs installed first..... by several people.... like I said a lot of wrong info out there...


...

 

I wasn't suggesting that you change to a four bar, only pointing out that the design of a hairpin does cause the Camber to be different as it moves thru its travel, so measuring caster only tells you what it is at one point. Also since it moves "somewhat" independently of the other end of the axle, that range of movement coupled with an incorrect shock choice might be something that causes your current problem. I hope you find the source of your problem and just offered that as a consideration/explanation .

 

ekimneirbo: I agree a 4 bar frees up the front while controlling the changes that happen thru the suspension range. Hairpins and split bones are somewhat restrictive but have been used forever.. Been using P&J's shocks almost exclusively since I started. I did put Ride Tech's on all 4 corners of my daily driver deuce pickup. Are the Ride Techs worth almost $800 more than the P&J's shocks??????????????

 

You might remove the P&J shock on the worn tire side and see if it still provides significant resistance when opening and closing by hand.
My P&J fronts only lasted 20k miles. I could open and close them by hand very easily.
Then remember that shock is trying to control the front corner that weighs around 700 pounds.

 

I have a set of So-Cal front shocks for my A sitting in the garage. They're easy to move and they're brand new.

 

If they are easy to extend and compress, they likely will not control the spring responding to the 700 pound corner weight bouncing up and down on highway bumps and bridge escarpments.
The Bilsteins that I used as replacements were pretty tough to compress during installation. And 45+k miles they still control the ride and have provided good tire wear.
Just my experience.

 

Yes average weight on the Front Right
Is 650 pds ,
@krylon32 is there a shop in your area that has a Hunter machine that know how to use Manually .
Its some work , I would set up car on
Stand to Ride height & ride rake
Pull wheels , plum bob rear to floor
Mark Then pull front spindles machine
Round stock the size of king pins with point long enough to slide threw axle
To floor mark to get left & right wheel base . Then use angle finder off the
Pin to get / Measure camber to compare each side or use this on the rotor's.

Also scale all four corners .

 

pprather: P&J's are long gone for the last year I've been running Ride Tech's