55.2-59 1955-59 Chevy 4x4 Power steering problems

[1957Napcofan]

I have a 56 Chevy 4x4 with the stock frame and using the CPP 400 Power steering box. Have a GM 10 bolt front axle with brackets welded to allow stock shock location. I used a late 70's Ford F250 steering arm. Truck is just about undrivable with this setup. Will not track and has way too much play. Also using a double steering stabilizer. New ball joints, tie rods, steering arm. Truck tracks straight down the road when you follow it and thrust angle is good on the rear axle.Toe is about a 1/8" Camber 1 deg and Caster is 6 degs. From other forums I found that most guys that are running a GM 10 bolt or Dana 44 prefer 6 degs.

When you turn the steering back and forth the steering arm goes up and down hill so the drag link from the pitman arm does not stay level. Could this be the
problem. At a loss to what else to check. Wheel bearings are not loose, don't see any play in the linkage. Really stuck and need help.

[scott123]

This is a shot in the dark. Check the pitman arm splines.

My truck drove fine til I pulled it in the shop to paint. There are X amount of splines on the pitman arm and I was down to whatever number is the bare minimum.

I replaced the steering box, then replaced that one as I thought the re-man was defective. Everything on jack stands moved as it should but going down the road, let's just say I used all of the road and a little of the shoulders, LOL

My son was watching it and his younger eyes caught the slight slip. Pulled it off and it may have had a 1/4 or so of the splines intact.

Never pulled a pitman arm of that style but just a thought.

Scott

[57tailgater]

It looks like that steering arm has too much lift, putting the tie rod connection up maybe too high as compared to the pitman arm connection. As you articulate the steering it will exaggerate the drag link angle. The short drag link probably contributes some too. That looks like a GM/Dana 44 4" lift arm. Don't know if there's anything with less lift.

[Hcb3200]

The cpp 400 box has a adjustment screw.
See how much slop is in the steering wheel before pitman arm moves as you move it back and forth. From the factory it was way off and had a lot of slop just in the steering box itself. we made it adjusted and that help greatly with the track. NOTE too tight and it will not return to center when you let go of wheel. you want to find the sweet spot between slop and steering wheel return.
Second. the rag joint can have some play as well. we had one that was new but the rubber was really soft and gave for more slop. its amazing how much 1 mm plays will affect a large steering wheel.
Third: you have a shorter drag link due to 4x3 vs stock straight axle and earlier years. The more its not parallel to the ground / frame the more its going to have impact on pot hole and bumps in road will have a large effect since its shorter.

[Hcb3200]

looking at the picture you may wan to move the drag link under the steering knuckle instead of on top and may it will help with all the angles at work with that setup. Hazards of straight axles and these older steering setups. lots of angles all affecting each other. Like a 50's truck mentor said to me. Son that truck you drive is like the picking the lottery or the stock market. you never know where its going to go when you bump something.

[1957Napcofan]

Thanks for all the input, going to see if I can modify the steering arm base to maybe get it to cycle more in line with the frame. Also if I can get some kind of
sway bar mounted that may help. Don't know if I could make the 2 wheel drive sway bar fit. I did adjust the play in the steering box weeks ago and that help a little.
Will check the rag joint. Have an aftermarket tilt column and wouldn't be surprised if it's got play.

[leegreen]

Is that the factory rear spring mount location or did it get moved rearwards for a longer spring?

I think the problem is the different length of radius between spring mount and axle (red line below) and on the drag link (blue line)



so as the axle moves up and down on a large radius and the drag link moves on a small radius the link end at axle moves front-back. This is bump steer. In a perfect setup the steering box is vertically in line with the fixed end of the spring and the drag link is the same length as fixed spring end to axle. Check a AD GM setup where the box is on top of frame right above spring. The TF trucks were less ideal with box in front of pivot, but remember the factory springs did not deflect much except on huge bumps, bias ply tires took some of the hit out of small bumps and trucks were slower.

leveling the drag link if it is not may help a bit as the further it is from horizontal the more for-aft movement there is to any given up-down travel. But the essential problem will remain unless you can get fixed spring pivot and steering box closer together.

Also, how much arc is in your springs at ride height, more arc means more back-front movement of the axle. If you have a lot of arc the axle will move forward on compression as the spring flattens and backwards on rebound as the spring bends. In this case a bit of downwards angle on the drag link may help, and in your picture you look to have upwards angle.

[mr48chev]

One thing not covered, How wide are the tires and how wide and offset are the wheels? deep offset wheels on solid front axles like to tell you what they are going to do far more than they like to do what you want them to do.

I don't see anything that much out of kilter on the spring or rear mount but not knowing the history of the truck I don't know how many miles are on the suspension. With my own truck even though it is a two wheel drive worn out parts let it have a mind of it's own. A bit of looseness here, a bit of slack there and a degree or two of caster off from where it should be and you have a rig that wants to fight you.

[1957Napcofan]

New steering box, drag link, center link , leaf springs, ball joints, wheel bearings.
Wheels are 15 by 8 from an 85 Blazer with 31 x 10.5 tires. There's about 15 miles on everything after a frame off restoration.

[leegreen]

I see lift blocks in the back are front springs arced to give more lift?
Do you have picture of same view as the one above but from a point of view level with the steering box with the weight on the axle?

[57tailgater]

From what I see in your pictures, if your caster is good, and all parts seems to have minimal play, I believe the angle between your red and blue lines could cause some issues. That shows 2 different radiuses/arcs that travel different distances as the suspension articulates. Maybe if you get them more parallel/similar to how the original orientation was it might help. If that is the adjustable drag link that came with the power steering kit, I also know those are shorter than the original ones. Bump steer can be hard to isolate.

[mat1968]

I have the same set up ad you and drives great . I do have the drag link more level. Did you torque the adjustment sleeve on the upper ball joint when you replaced them to preload it?

[mat1968]

Picture

[leegreen]

it appears mat1968's drag link angles down where 1957napcofan's angles up

for mat1968 as the spring flattens under compression and moves the axle forward the angle of the drag link will move the axle end of the drag link forward and up, so it moves with the axle

for 1957napcofan as the axle is shoved forward by the spring the drag link is going to pull the steering backwards

so why does the axle end of one drag link sit higher than the other?
Is that a lift block I see on mat1968? What does the large block under the upper ball joint do?

When the factory started using arced springs for softer ride with more travel they did something similar, steering box to drag link was a shorter radius than spring perch-axle and downwards angle to the drag link counters the spring moving the axle back and forth

[mat1968]

the block is just to rise the steering arm for a lift kit on a squarebody. mine is a kingpin dana 60 dually axle. but same geometry.

[1957Napcofan]

I will see if I can modify my steering arm to get it going downhill towards the front. I did torque the upper ball joint sleeves with the special socket
I bought just for that. Also might be able to find a different steering arm to use
It does feel like it bump steers and when you take a sharp turn and
the truck leans it wants to go in the wrong direction. Anyone know of a
sway bar that could work? Not much room to fit one in. Would be great to find one that has a hump for the front diff and bolt it to the u-bolt brackets and have
the sway bar links go straight up to the frame.

[leegreen]

squarebody 4x4 sway bar and crossmember? there is a thread on here somewhere with pictures

[mick53]

This is why this is a great forum. This is not my application but I have to figure mine out and I have learned a lot from this thread. Thank you.

[leegreen]

Have you played with tire pressure? It can make a huge difference in some vehicles. So can the tires themselves, all season type tread is more stable at speed than winter compounds and M+S tread patterns

If you have any easy way to get a couple inches lower on that link end try it and see. If it is not so easy I'd probably do some figuring with a full size drawing before starting any major work. Cardboard is cheaper than welding

Compress the spring to bump stop and measure how much the axle moves forward vs ride height and then how much it moves rearward with unloaded spring.
Break out a large piece of carboard and draw all the pivot points and arcs to scale, try and find a length and angle for the drag link that lets it match the movement of the axle for straight ahead driving.

there are lots of other opinions and experiences on this site

[1project2many]

Anyone know of a
sway bar that could work? Not much room to fit one in. Would be great to find one that has a hump for the front diff and bolt it to the u-bolt brackets and have
the sway bar links go straight up to the frame.

I ran a square body sway bar for years. I installed the sway bar bushings on the front of my '57 crossmember and welded bolts to the plates on top of the spring. The bar worked well but end of the RH side of the bar ended up under the RH frame rail which caused the bar to hit the frame on bumps.

I'm currently using a stock Task Force panel truck bar and it works well. But I measured a 95 YJ front bar and I believe that might work as well. reverse the bar mounting so the bushings are mounted under frame rails and the links connect to the axle and you might be good. The picture is from a JK. Same idea.

[1957Napcofan]

Originally Posted by leegreen

Have you played with tire pressure? It can make a huge difference in some vehicles. So can the tires themselves, all season type tread is more stable at speed than winter compounds and M+S tread patterns

If you have any easy way to get a couple inches lower on that link end try it and see. If it is not so easy I'd probably do some figuring with a full size drawing before starting any major work. Cardboard is cheaper than welding

Compress the spring to bump stop and measure how much the axle moves forward vs ride height and then how much it moves rearward with unloaded spring.
Break out a large piece of carboard and draw all the pivot points and arcs to scale, try and find a length and angle for the drag link that lets it match the movement of the axle for straight ahead driving.

there are lots of other opinions and experiences on this site

Have crap tires on it now till it gets sorted. Run BFG K02's on every truck I've
owned. We get serious snow here, all season tires wouldn't cut it. Have
Michelin Cross Climate 2 all seasons on my Crosstrek, those are great tires
even though there all season. Rated for extreme snow but have a 60K warranty. Have a "V" pattern like a tractor tire. I enjoy driving by BMW's
and MBZ's that are stuck in the snow when the flatlanders come up with
there stupid cable chains. Thanksgiving 2019 we got 42", super fun

[leegreen]

OT Japanese 4x4. Cheapo walmart brand all seasons were fine, ran them at 32-34 PSI. got down to the 60% range where AS are no good for winter. Picked up a nice set of Michelin winter specific tires. At 34 PSI the truck was all over the road, did not feel very safe on the highway, just night and day difference. I thought a bushing must have torn or something when I jacked it up but could not find anything loose. Puzzled me for days until I dropped the pressure down to 26F / 31R as specified on the door frame. problem solved
26 is lower pressure than I have run in street tires -ever-

A pair of new front tires can compensate for worn out front suspension for a while. Favorite trick of bottom feeder used car dealers.

Other people have gotten away with a link setup just like yours. Easy things first?

[1957Napcofan]

Found the problem. I had used the old front leaf spring rear pin bushing bolts. From the assembly manual it shows to have the machined portion of the bolt installed down. On the left spring I had it installed at the 9 o'clock position. So what that caused is when I turned the wheel the left leaf spring would move back and forth and move the front axle. The new style pin bolts are a better design and don't have to be timed. I also machined down my steering arm to make my drag link level.

[dsraven]

are you saying the original pins come half wore out?
all season tires are for spring, summer and fall, not winter. the rubber is hard when it is below zero. after 28.5 years of emergency services work I can tell you that 90 percent of winter collisions are caused by poor tire choices, most of which boils down to being too cheap to buck up for the cost of wheels and actual winter tires. also the reason why intersections are shone up and icy-the all season guys spin the tires at max speed and make a skating rink on the corners and intersections
I run michelin Xice tires on the wife's "18 acura rdx and bridgestone blizzaks on my '15 silverado. the xice wins the grip competition. I run the silverado in auto 4x4 but the acura still wins the traction race. probably partly due to axle weights per tire being a llot different on a pickup. less pressure is a given for winter grip and I usually run the low end of the pressure range for winter.

just got rear ended this last sunday by a young fella who was running all season tires on a 2021 mercedes benz GLC. well, actually it was his momma's car, the reason why he didn't know where to find his 4 way flashers (or even what the switch might look like). also the reason why his vehicle registration (tags for those south of the border) was expired last july. I got out to see if he was ok and he was on his phone. duh, he was lost and had to call mommy for directions. he rolled the window down and I told him to put his 4 ways on, he didn't know where to find them and even asked me. I reached accross and turned them on. when he got out to talk he said his brakes didn't work. well, they work it's just that the all season tires don't when it's minus 25 celsius.
sorry, end of rant

[1957Napcofan]

The original pins where machined that way for room for the grease. The new pins don't have the same design as you can see in the picture. As for the Michelin All Season Cross Climate 2 tires, they are rated for extreme snow conditions. They have the 3 snow peak rating and are soft in the cold. They have a V pattern and work really well. They don't become hard like hockey pucks like the rest of the so called all season tires when its below 40 degs.