Front axle off set to passenger side

[Keith Seymore]

Lol!

I was the "brake pull" guru. I used to travel to dealerships to fix trucks they couldn't fix.

The 1/2 leaf shown above was my invention (an old MOPAR trick).

K

There were a few inherent problems:
a) Once a customer was "tuned in" it was nearly impossible to fix it well enough for them to be satisfied. We even bought back some trucks and the customer went out and purchased a new truck that was identical to the old one.
b) Short wheel base/ high center of gravity of the Blazer made it especially susceptible.
c) The fore/aft steering drag link was a huge contributor. The drag link is "compressed" as a result of front axle spring wind up during braking. Because it is a rigid member it would either (1) physically input a RH steer into the front wheels, or (2) rotate the steering wheel to the left (when stopping with hands off the wheel).

There was a lot going on with these poor trucks.

K

 

[AuroraGirl]

There were a few inherent problems:
a) Once a customer was "tuned in" it was nearly impossible to fix it well enough for them to be satisfied. We even bought back some trucks and the customer went out and purchased a new truck that was identical to the old one.
b) Short wheel base/ high center of gravity of the Blazer made it especially susceptible.
c) The fore/aft steering drag link was a huge contributor. The drag link is "compressed" as a result of front axle spring wind up during braking. Because it is a rigid member it would either (1) physically input a RH steer into the front wheels, or (2) rotate the steering wheel to the left (when stopping with hands off the wheel).

There was a lot going on with these poor trucks.

K

Id just be happy to have rear brakes and front hoses just kinda "done" for me with a blink of an eye and maybe a cab floor and then I would in heaven if my u joints/front axle were just perfect and then I could enjoy square (Not rn with gas lol) But then I wake up and cry because Its not going to happen unless I do it >.>

 

[Keith Seymore]

Caster is easily explained. Assuming you have ridden a bicycle before and assuming you were as dumb as I was when I was a kid...

If you are riding a bicycle the front wheel sits in front of the pivot point which gives a +, positive caster. The bike naturally wants to go in a straight line.
If you turn the handlebars completely around (180) where the tire is now tucked up underneath you, that is -, negative caster. The steering is twitchy and it becomes very difficult to hold a straight line.

Obviously there is more to it than that but this will hopefully give you a decent idea of what is happening.


As far as what moved on the rear, probably nothing. The thrust angle probably did change slightly based on the toe adjustments on the front but the change on the rear toe measurement is most likely just that the instrument moved slightly or that the readings are right on the edge between two numbers. I wouldn't worry about that at all, it is of no significance.

Good example. I like to think of the wheels on a shopping cart. Same thing.

We used to crank the caster up as much as we could - like 10 or 12 degrees. Assuming the steering gear is tight that will make it feel really solid on center.

K

 

[iamtherealJayy]

How is the caster adjusted on these trucks?

 

[Keith Seymore]

I am going to suggest taking it to a frame shop and having them put it on a lift, hang the gauges and get the tram gauges out.

I bought this truck a couple years ago and looked over it carefully before I paid him. I knew it was wrecked at some point because the left 3/4 front sheetmetal was replacement GM parts with stickers. Crawled underneath it, didn't see anything that was a deal breaker. It drove ok after changing a couple bad front end parts and new tires, had the transmission rebuilt, they didn't say anything.

Pulled the bed and dropped both tanks and found the frame kinked in the center, the tanks blocked the view. When they "fixed it", they bent the cab mounts to level the cab. I had previously ran a Carfax prior to purchase and there was no accidents listed and it was one previous owner. I bought it off the grandson of the 90 year old couple going into assisted living home.

First, found a guy who could do it, not easy today with production shops everyplace here, he racked it and showed me 5 other areas out of place. I have been waiting for him to get to it, he is 4 months out on appointments.

With these trucks being around 35 years old, many of them have numerous stories hidden in them. With this being wrecked in the front and a loaded trailer swinging off the hitch at the time, I can only imagine what they will find.


The shimmy that comes and goes, I would bet is a tire with a shifted belt. Quick test is to lower the air pressures in the suspect wheel and take it for a spin. I used to shift belts all the time running at max PSI on company trucks, drop them dow so it drove better and the shifted belt went away.

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Apples and oranges.

The "beam type" front axle of a K truck vs the unequal length control arm independent design of the C truck are entirely different animals.

K

 

[Keith Seymore]

How is the caster adjusted on these trucks?

By inserting tapered shims between the spring and axle pad.

K

 

[AuroraGirl]

By inserting tapered shims between the spring and axle pad.

K

Also one could probably depressure or modify the flow control valve / union orifice to change the flow/pressure to make the power steering less buttery smooth, or would that not make much difference on trucks like this? I am not the one to change butter steering, I like it, but I suppose if assist is lower the tenndency to go anywhere but the natural "on center" steering would be lower?

 

[iamtherealJayy]

Brake lines look perfectly fine. I made sure not to rotate caliper when I had them off. I just checked them. Nothing in the steering feels loose, atleast not loose enough to move by hand.

 

[iamtherealJayy]

Yesterday when I was messing with the truck I was turning the wheel back and forth(engine off) and I started hearing a fluid under pressure noise and it turned out I was pushing fluid out of the power steering cap. Is this normal if you’re turning wheel back and forth(not a whole lot maybe a half rotation left to straught to half rotation right at the max) I just assumed it was gearbox pushing fluid through return. I started the truck after I noticed the leak to hopefully stop it.

 

[AuroraGirl]

Yesterday when I was messing with the truck I was turning the wheel back and forth(engine off) and I started hearing a fluid under pressure noise and it turned out I was pushing fluid out of the power steering cap. Is this normal if you’re turning wheel back and forth(not a whole lot maybe a half rotation left to straught to half rotation right at the max) I just assumed it was gearbox pushing fluid through return. I started the truck after I noticed the leak to hopefully stop it.

Sounds like it wasnt bled. but Ive only seen a ford do that when turned off, ive never seen a gm do that. I guess I havnet tried it on the square either but have you done a fill and bleed on the truck>? and whats the condition of your cap?

 

[iamtherealJayy]

Never had a problem out of it, but then again I’ve never turned the wheel back and forth with the engine off. I assumed it was fluid returning from gear box and not pumping to gear box, that’s why I started the engine when I noticed it.

 

[Wilfred]

Are you missing a top leaf? Looks like the keepers got some room to take another in the first series of pics from 3-8-22

 

[Grit dog]

Have you swapped to some different front tires yet? By all accounts your steering should be pretty good, save for some play in the steering box.
Simple test, just swap front to back and see if the shimmy goes away.

 

[iamtherealJayy]

I drove truck to work today and I didn’t have any vibrations, although my steering wheel is turned to the right a little, I’m thinking the steering box is a bit loose because I could turn the wheel straught but the truck would slowly start inching left there’s maybe 4” of back and forth movement holding my hand on the wheel. The only shake I had was going through an underpass and I hit a pothole and I felt like one of those low riders with hydraulics lol. It felt like the front end did a wheelie and kept bouncing

 

[iamtherealJayy]

On the ride home the truck did shake a little I mean it was so little I wouldn’t be concerned about it. Just enough to make your arm fat jiggle some. It did shake a little more when I let off the throttle but not as bad as it had been. So could something have been too tight and it’s breaking it? Still nothing looks obviously wrong yet.