Steering Mystery - I Need Help!

[truckster]

I have a 1972 K/5 Blazer 4WD with factory power steering.

The front U-joints were making noise, so I decided to replace them. As long as I was going that far, I decided to replace everything under there, from the carrier bearings out. I installed new upper and lower ball joints, tie rod ends, new spindle and wheel bearings; everything replaceable. I used Spicer, Timken, and Moog parts - no cheap stuff. I also installed 3 degree caster shims between the leaf springs and the axle perch with the fat end toward the front. I set the toe-in at 3/16".

I just took it out for a drive and it's all over the road - way worse than before. Everything is tight when it's sitting, but I get up to 25 MPH and I have to make constant corrections to stay in my lane. I've thought about pulling out the caster shims, but maybe I'm missing something.

Any ideas?

[ZEKE68]

Is your axle mounted below the spring or above? If it is mounted below the spring, and you put the fat end of the caster shim it the front, you removed your caster. Also have you checked the drive shaft angle?

[Getter-Done]

I suggest to take the shims back out.
It will not cost you any money and will Probably fix your issue.

[truckster]

The axle is mounted below the springs. Would reversing them increase the caster, or should I just remove them altogether?

Getter-Done, I agree it's no cost and a fairly easy fix. But I'll already have it jacked up, and if I can improve the steering by increasing the caster I'd like to try that... [Edit] I'm overthinking it. I'm just going to pull them out.

Do I have the toe-in correct at 3/16"?

[Getter-Done]

I looked at a few old threads and that is what other members set their toe-in at.
If removing the shims doesn't solve it I would try just a little less toe-in.

[truckster]

Originally Posted by Getter-Done

I looked at a few old threads and that is what other members set their toe-in at.
If removing the shims doesn't solve it I would try just a little less toe-in.

Yeah, this board is where I got the information on the shims, but they're coming out. Driving it like this is just plain scary.

[Getter-Done]

Originally Posted by truckster

Yeah, this board is where I got the information on the shims, but they're coming out. Driving it like this is just plain scary.

I had a short-bed truck with shims that PO installed
and I had to remove them because of the wandering issue.

I don't know if that is your issue also.
That would be easy if it is.

[A1971Blazer]

Do you have factory front springs or lifted springs?

[truckster]

It has factory springs. I removed the shims and it's better but still feels really loose. I'll get on it next week. I might try tightening the steering box, but it hasn't changed since I put it in the garage a week or so ago.

[A1971Blazer]

did you check the spring eye bushings? if they’re original, it’s possible they are worn out.
maybe get another set of eyes on it while you’re turning from side to side
I just rebuilt the entire front axle and put new springs on my ‘70 Blazer and it drives better than new…obviously something isn’t quite right with yours
god luck with it, let us know when you get it figured out

[truckster]

I replaced those a couple of years ago. The strange thing is that it wasn't this loose before I replaced the ball joints and tie rod ends. Maybe I should increase the toe-in.

[cj847]

I recently had a jeep with similar issues. Here is what happened in my case.

It was "wandering" going down the street. It was ok on a smooth surface but was hard to maintain my lane when potholes were encountered. The axle was substituted in from another vehicle (ie no way to know if it was right for the leaf setup I had)

When I got the "after" alignment specs I noticed that the caster did not have a reading. The guy mentioned it is not adjustable, so he added a little toe in to help compensate for the basically zero caster.

It drove better but not great. So, I took it to the 4x4 shop and had 4 degree shims put in. It was a whole new truck after that.

In your case, it sounds like you've done a spring over and who knows what else (ie who welded the pads on the axle and are they perfect or even the same?)

If there is an old school alignment shop in your area it would be worth it to find out where you are starting from. (I know it is frustrating to pay for an alignment when the only adjustment they can make takes about 1 min).

[truckster]

Originally Posted by cj847

In your case, it sounds like you've done a spring over and who knows what else (ie who welded the pads on the axle and are they perfect or even the same?)

If there is an old school alignment shop in your area it would be worth it to find out where you are starting from. (I know it is frustrating to pay for an alignment when the only adjustment they can make takes about 1 min).

The front axle and springs are bone-stock original equipment. The only thing that has changed are new ball joints and tie rod ends, and those are all Moog parts.

[Getter-Done]

Is the frame cracked at the Steering box?

I always add a brace on the frame, For the steering box.

Your Frame could be flexing (More) now that everything is (Tight and Right).

[truckster]

Originally Posted by Getter-Done

Is the frame cracked at the Steering box?

I always add a brace on the frame, For the steering box.

Your Frame could be flexing (More) now that everything is (Tight and Right).

It's a good idea to check that. I welded a fish plate on it a few years ago, but it's worth taking a closer look. Thanks.

[cj847]

Originally Posted by truckster

The front axle and springs are bone-stock original equipment. The only thing that has changed are new ball joints and tie rod ends, and those are all Moog parts.

Sorry, my mistake, I was thinking GM was spring under from the factory.

[Getter-Done]

I have bought and also fabricated braces like this in the link below.

Link: https://www.offroaddesign.com/bolt-i...wd-trucks.html

These really help.

[truckster]

Not a bad idea. I could weld up something like that pretty easily. I do have a straight brace across the front of the frame.

[tim_mc]

I recently snugged up the steering play in my reman Lares steering box. Made a world of difference.

[Richard]

If the front end is all stock, front driveline can take the extra pinion angle no problem. Use the degree shims with the fat portion to the rear of the truck. Stock caster is only around 4 degrees on these old 4x4's. Adding the 3 degree shims will get you near the alignment specs of the later 4x4 solid axle trucks.

[bowtie72]

Leave the shims out. If you don’t have the equipment to measure the caster and camber I wouldn’t throw parts at it expecting good results when you don’t know where it is at to start with. Check your spring bushings and the shackle hanger bushings. This is a weak spot. Replace them with poly bushings will make a big difference. Toe should 1/16-1/8” in. Anything else will eat your tires up. The rubber bushings allow a lot movement.

[truckster]

Thanks. I have poly bushings in the springs and shackles.

[KQQL IT]

Originally Posted by truckster

I have a 1972 K/5 Blazer 4WD with factory power steering.

The front U-joints were making noise, so I decided to replace them. As long as I was going that far, I decided to replace everything under there, from the carrier bearings out. I installed new upper and lower ball joints, tie rod ends, new spindle and wheel bearings; everything replaceable. I used Spicer, Timken, and Moog parts - no cheap stuff. I also installed 3 degree caster shims between the leaf springs and the axle perch with the fat end toward the front. I set the toe-in at 3/16".

I just took it out for a drive and it's all over the road - way worse than before. Everything is tight when it's sitting, but I get up to 25 MPH and I have to make constant corrections to stay in my lane. I've thought about pulling out the caster shims, but maybe I'm missing something.

Any ideas?

Fat end of shim goes to the rear?
You took caster away which would make it turn like a shopping carts with a bad wheel.

[Sicklajoie]

Axle above the spring - fat end on the front.
Axle below the spring - fat end to the rear.

[dmjlambert]

Just wondering here, are 4WD susceptible to the same infamous steering center link installed backwards that 2WD C-10's get?