55.2-59 Alignment thoughts for a 1956 with stock arms / Tie Rod WITH Power steering

[Hcb3200]

Ok
Read thru a mountain of threads. And found this to be true. Its all over the place both the truck and the threads. LOL

So current setup.
stock arms, axle, tie rod, tie rod ends, spindles, drag link.
Has CPP power steering pump in stock location inside frame rails.

Fat tires compared to stock these are big 265/75/r17 wheels.

Done all the basics when I redid the king pings. All new pins, bushings. made the tie rod ends tight. All greased up.
She steers much smother. starts to return to center now that she is greased. Tracks straight and good on smooth roads.
But as soon as the road is not smooth or need to slow turn left or right lets just say she floats all over.

I have made the steering box as tight as i want to based but it may have a very small adjustment that can be made.

Looks to have the stock shim on axle for caster. (forgot to measure when I had it out for king pin redo)
Plan on taking it to alignment shop to have the actual numbers looked at. But want thoughts before the wrenches start turning.

Thoughts on increasing caster and toe would be appreciated with this setup with power steering. I have read where a increase of caster with power steering helps on the road wander.
But have seen everything from 2.5 to 3, to not over 3 or it worse, to 5 to 7 on all the thread i have read.

Anyone running setup that i have that has measurements.

Fire away>

[leegreen]

try lower tire pressure first?

[1project2many]

There's really no need to make substantial changes to the manual steering alignment values.

Caster can only be adjusted by placing a tapered wedge under the axle. Camber adjustments aren't provided. Significant camber errors mean bent spindle or axle. Axles can be bent to make a correction. DO NOT apply heat.

Alignment specs I would keep in mind if I were doing the alignment:
0.50 degrees positive camber L and R.
2.5 degrees positive camber on the right
2.0 degrees positive camber on the left
3/32" toe

Camber window is 1.25 to 1.75 degrees. Truck pulls to most positive camber and least positive caster. Alignment tech must balance camber and caster to make the truck drive straight. Example: 1.7 degrees+ camber RH and 1.25 deg+ LH will pull right. So caster setting may end up at 1.75 deg+ L and 2.75 deg+ R to offset the camber.

If the alignment is correct and the truck still wanders then the issue is more than likely something other than alignment.

Years ago I put a 57 GMC power steering system into a 55 Chevy 3100 truck. GMC used a power steering box rather than a power assist cylinder so the setup was like what you're running. The truck was running a large set of Mickey Thompson bias ply tires. I saw first hand that the forged steering arm was flexing allowing over 1/8" movement of the drag link with no corresponding movement in the wheel. Since then I've been able to demonstrate on a number of occasions that it takes very little force to cause the 1/2 ton arm to flex.

Watch this video and notice how much the steering arm flexes. This is with a tiny amount of pressure applied to the wheel in a manual steering system. On my truck with PS and wide tires, the arm flexed before the wheel and tire even started to turn! https://www.youtube.com/watch?v=Qlk6fzx_GDc

I'm not a superhero. If I can see this happening in the shop then I guarantee it's happening on the road.

I have upgraded to 3800 (3/4 ton) steering arms and 1" tie rod. I have added an OEM sway bar from a panel truck as well. The truck drives so much differently now. The steering arms bolt on with no modifications. My 1" tie rod was machined years ago, before you could by them, and uses stock ball and socket ends so I purchased a set of 3/4 ton ball studs to re-use my tie rod.



I haven't rebuilt the steering box yet so there's play in the bushings, yet I can drive at 45 or at 85 with ease.

I had trouble finding used arms for a while. I eventually contacted a seller that had a *bunch* of other TF parts listed on E*bay and they sold me a pair off a truck they were stripping. If you want to search by OE part number, the numbers are listed below.

1/2 ton to 3/4 ton steering parts interchangeability			
			
Part Description	Group Number	Part Number	Casting Number
Ball stud, 3/4t		6.243		377992	
Arm, L, 3/4		6.103		3667727		3713017	
Arm, L, 1/2		6.103		3711883	
Arm, R, 3/4		6.103		3728383	
Arm, R, 1/2		6.103		3728389		3711777

[1project2many]

Just wanted to add a link to the post with pictures of 3/4 and 1/2 ton steering arms side by side.

https://67-72chevytrucks.com/vboard/...03&postcount=9

[mr48chev]

You absolutely do not want 1.5 degrees of camber with 10.4 inches of tread width unless you want to replace the tires in 2000 miles. That nonsense is out of alignment not in line.

That might fly with skinny tires with 4-1/2 inches of tread on the ground but with a 265-75-17 with a 10.4 inch wide tire the weight would be riding on the outer third or less of the tire. Actually This time 1project2many is telling you to put your truck out of alignement or his numbers are way off.

You do want 1/4 more positive camber in the drivers side wheel than on the passenger side. Not more than 1/2 degree positive camber in the drivers side wheel or you put too much weight on one side of the tread rather than having the weight evenly distributed. The wider the tires the less camber you want if you intend to have your tires last the miles that the manufacture says they should.

GM factory specs for a 56 pickup say 1-1/2 positive caster for an unloaded static truck and 3 degrees for a truck at capacity load. I'd go with the 3 degrees. It should track good but not put all that much force on the linkage.
1/8 toe in.

The 5 to 8 degrees some guys throw out is what most Ford hot rodders find works in a Model A through late 30's Ford I beam hot rod. Tracks great at speed and the car is light enough it isn't that much of a make your arms stronger turning at low speeds. Most Ford hot rods don't have wide tires on the front although "street rods" might.

I've aligned somewhere between 2 and 3 thousand front ends in my lifetime and have had guys walk in wanting their rides set at crazy specs they saw in a magazine or later on the net. Most of the time those specs came about because someone was setting up a car or truck for a specific type of racing. Remembering in the 80's when some magazine writer did an article and said to set the car up with 2 degrees negative camber. That works on a road race car or streetkana car or truck that isn't street driven but is about what you see on the local Honda lowriders with the tires leaning in at the top at crazy angles and those kids buying tires every 10 K instead of the 60 K those tires should go on a properly set up suspension.

The old factory specs don't jive with modern wide tires on any type of vehicle. The high camber angles were intended to have the car/truck drive straight on rough or dirt/gravel roads from the time frame and a 7.10 was a "wide" tire.

[1project2many]

Actually This time 1project2many is telling you to put your truck out of alignement or his numbers are way off.

Thank you! Yes, I'd look for .5 degrees positive both sides. That's a visit from the screw-up fairy. I've fixed it.

I've always preferred using caster to offset road crown. I do not prefer setting different camber L to R unless the vehicle or the way it's used tells me it's necessary.

[mr48chev]

Originally Posted by 1project2many

Thank you! Yes, I'd look for .5 degrees positive both sides. That's a visit from the screw-up fairy. I've fixed it.

I've always preferred using caster to offset road crown. I do not prefer setting different camber L to R unless the vehicle or the way it's used tells me it's necessary.

I was taught to use camber but it works either way. Normally 1/4 more in the drivers side offsets the crown unless you are in an area with a lot more crown or one of those areas in the southwest with less than normal crown.

When I subframed my 48 in 1981 I didn't have alignment equipment in the school shop and took it to the go to old time front end shop in town owned by a gent named Cooper and his butt lazy son. Old man Cooper may well have been one of the best alignment men in the country even though his dark, dirty and dingy shop didn't have any fancy equipment. He set it up and we actually took off to Texas with less than 80 miles on a fresh build and that truck would hold a straight line in SE Idaho on US 84 for a mile or more with your hands off the wheel.

HBC 3200, I would still keep a real close eye on those front tires and if you have same size tires all around rotate them at lower mileage than the tire shops reccomend. If you had skinny Bias tires on it or skinny Radials I wouldn't be all that concerned but wider tires on straight axles want everything perfect.

[Hcb3200]

Good news is you guys are providing all the right information.
Bad news is truck is in one state and I am in another.
Better good news is I found a local alignment shop near the truck where the owner is older than I am. His equipment has the specs in the computer and he is getting scheduled to get me so actual numbers in its current state. Hopefully next week depending on my sons schedule. soon as the real numbers are in my hands I will post them up. depending on what we find out will know what direction to head in. Keep them coming this is turning out to be a good thread of information for us wide tire guys.