Need help with caster adjustment

[gcsupraman]

So went to get an alignment today on the 1972 K20. I've been having steering issues with the truck for the past two years and finally bit the bullet finished replacing the last of the front end wearable parts.

The alignment machine shows the following for the caster:
Left Front 1.1 degree (spec 3.5-4.5)
Right front 3.1 (spec 3.5-4.5)

I am having a hard time figuring out how to find a solution - partly because one side is so far off from the other. I looked on diy4x4 and found a set of 4degree axle shims - but that puts me out of range. I don't believe I can run a shim on only one side either. I also know there is a caster shim set available that (I believe) attaches to the ball joint. Problem is, the maximum shim only offers +/- 1.5degrees of caster so my left side will still be out of spec.

The only thing I can think of is cutting the left spring perch off, adjusting it and re-welding it. I wouldn't even know how to pull that off unless I found an alignment shop that could also do the welding - otherwise we would just be guessing at the proper setting and that would get annoying and expensive quickly.

Any other idea or tips would be appreciated!

-Greg

[Mkcustums]

There are a few things that could be happening, but you said you replaced everything? What all does that include? First thing that comes to mind for me since you said the last 2 years would be something bent or worn. Shackles, worn eye bolts and bushings, axle tubes... (lots can happen) A lot of times to spot something you need to be there in person to see. I know, that doesn't help either.

[gcsupraman]

Originally Posted by Mkcustums

There are a few things that could be happening, but you said you replaced everything? What all does that include? First thing that comes to mind for me since you said the last 2 years would be something bent or worn. Shackles, worn eye bolts and bushings, axle tubes... (lots can happen) A lot of times to spot something you need to be there in person to see. I know, that doesn't help either.

Ok - maybe not everything

I replaced the steering box, drag link, tie rod ends and all 4 ball joints. I just went outside and inspected the shakles and axle tubes - nothing obviously bent. I did notice a little (and I mean little) play when I turned the wheel back/forth in the front left spring bushing - i assume this is the eye bolt/bushing you were referring to.

What do you suggest I do next?

[gcsupraman]

My best idea at this point is to just run 4 degree axle shims and have 5.1/7.1. but the 2 degree different is pretty significant - something must be causing it.

-Greg

[Mkcustums]

If your bushings are worn it can cause your axle to hang one way or the other. I wouldnt run shims, just try to fix what the issue is first. If you start adding shims to fix it there is a big chance it will just cause a new problem.

If you can get it on a lift or on stands and get the weight off the front end, try that and move things around when the weight is off the axle. Even if you just do one side at a time, see if things move unlike how they should.

[gcsupraman]

Originally Posted by Mkcustums

If your bushings are worn it can cause your axle to hang one way or the other. I wouldnt run shims, just try to fix what the issue is first. If you start adding shims to fix it there is a big chance it will just cause a new problem.

If you can get it on a lift or on stands and get the weight off the front end, try that and move things around when the weight is off the axle. Even if you just do one side at a time, see if things move unlike how they should.

I got under the truck in the last ounce of light for a further inspection. I can move the spring packs side to side when prying with a large screwdriver against the shackle. Not a ton, but I can definitely move them even with weight on the truck. It looks like the passenger spring pack has shifted almost up against the shackle - it was hard to tell but it looked like the spring with the eye hole is about 2/3 of the way to one side but the rest of the spring pack is almost touching. I noticed only 1 spring clamp in the rear of each spring pack (none on the front) - is it normal to only have one?.

Mkcustums, I appreciate your help. I am going to jack the truck up tomorrow for further inspection. I am also going to check the spring pack center bolt to make sure it's not broken. I will report back.

Thanks

-Greg

[Mkcustums]

No problem, I just hope you get it all figured out.

Yeah, just having one of the spring clamps is fine. Some people remove them that wheel that want more flex, or open them up so they are in a │_│ shape and leave it open at the top. Those mainly keep the leafs from spreading apart.

Id definitely take a good look at those bushings, the fronts too while your at it. Poly bushings are a good replacement too if you decide to replace them.

I'm curious as to what you find tomorrow, so let me know. If you have anymore question feel free to ask!

[gcsupraman]

Originally Posted by Mkcustums

No problem, I just hope you get it all figured out.

Yeah, just having one of the spring clamps is fine. Some people remove them that wheel that want more flex, or open them up so they are in a │_│ shape and leave it open at the top. Those mainly keep the leafs from spreading apart.

Id definitely take a good look at those bushings, the fronts too while your at it. Poly bushings are a good replacement too if you decide to replace them.

I'm curious as to what you find tomorrow, so let me know. If you have anymore question feel free to ask!

Ok - finally got outside after the rain let up and got to work on the left side only. I removed bolt ubolts and checked the spring pack center pin and its not broken. I jacked the truck off the ground and with a crowbar tried to move the spring (at the eyelet bolt). Everything is tight there = just a little play in the bushing from side to side when I pry on it - doesn't seem abnormal.

I also wacked the rear shackle a few times with a BFH to see if there was play front to back. Nothing.

Getting a little discouraged

-Greg

[LONGHAIR]

The problem that you are facing here with a straight-axle truck is that the caster was not ever intended to be "adjustable"....at least independently.
Furthermore, they were rather crudely assembled in the first place. You are measuring more accurately than most people would.
If you are not having issues while driving, I would worry about it too much. If so, a small shim will help with the side that is under-spec. Having the other side slightly over-spec won't hurt anything. All it can ever do is increase the steering effort required (slightly), you may never notice it.

If you need to get it perfect, it can be done by installing the adjustable ball-joints in opposite directions. Installing one to the positive and the other to the negative....you could get them exactly even, then shim the entire axle to get them both into spec....

IMHO, it's not necessary though, it is a truck after-all....and it's not likely that the tires you use will ever be so perfect that any of this matters. It's not a Ferrari

[Mkcustums]

I agree the same, I just figured since he said "the last two years" meant it was pulling or something, causing an issue. With that, just thought someing was off or loose causing a bad driving experience.

If it tracks good, drives good, tires are not wearing bad, run it. Ignore the numbers the alignment says.

[Mkcustums]

Originally Posted by LONGHAIR

IMHO, it's not necessary though, it is a truck after-all....and it's not likely that the tires you use will ever be so perfect that any of this matters. It's not a Ferrari

Most people don't see what a bare steel rim looks like on a balancer, even brand new out of the box. (not always good) Then throw a tire in the mix... Performance radials are usually good, P are tollerable, LT's are worse, then bias are usually horribile!

Bla bla bla... anyway...

[Mkcustums]

gcsupraman Is it driving bad or causing issues?

[gcsupraman]

Originally Posted by LONGHAIR

The problem that you are facing here with a straight-axle truck is that the caster was not ever intended to be "adjustable"....at least independently.
Furthermore, they were rather crudely assembled in the first place. You are measuring more accurately than most people would.
If you are not having issues while driving, I would worry about it too much. If so, a small shim will help with the side that is under-spec. Having the other side slightly over-spec won't hurt anything. All it can ever do is increase the steering effort required (slightly), you may never notice it.

If you need to get it perfect, it can be done by installing the adjustable ball-joints in opposite directions. Installing one to the positive and the other to the negative....you could get them exactly even, then shim the entire axle to get them both into spec....

IMHO, it's not necessary though, it is a truck after-all....and it's not likely that the tires you use will ever be so perfect that any of this matters. It's not a Ferrari

Longhair/MK, thank you both for your assistance. Just to clarify, I've owned the truck for about 2 years and it's driven pretty horribly ever since I bought it and almost brought me to the point of just selling it - I'm talking straight up scary to drive. I found it had a broken center pin in the rear spring pack that caused the truck to swerve when I let off the accelerator, it had play in the steering box (replaced that with an AGR box) and the drag link (replaced that). It also had an axle joint that was completely frozen so when the truck turned it would all of the sudden dart off to the side of the road. As if those issues weren't enough, the truck would always wander all over the road - especially at highway speeds.

So..... I finally had enough and replaced the upper/lower ball joints and tie rod ends too. During my research on this message board I noticed that a low caster number can cause wandering at highway speeds as well as the steering wheel not returning to center (which mine does as well). I guess the low caster could have been partially caused by the heavy duty leaf springs the fire department installed on the truck (4 leafs in the front, 6 in the rear+overload) which gave the truck a small lift

At this point I have pretty much checked everything. Longhair, maybe to your point they weren't very accurate in the first place. From what I read, I believe around 5 degrees is what most people are aiming for on a dana 44 front end. I can get a set of 2 degree axle shims and a 1.5 degree adjustable ball joint sleeve for the left which will net me 4.6 left, 5.1 right or get a set of 4 degree axle shims and get two +/- 1 degree sleeves (one for each side). This will net 6.1 left and 6.1 right.

Based on all of the issues I've had and the $1500 I've spent parts and labor to fix this steering issue, it's my mission to get this caster in spec as there are not to many other causes of my wandering issue. Money really isn't an issue, I just want the truck to drive straight down the road!

Thanks for your help

-Greg

[gcsupraman]

Originally Posted by Mkcustums

Most people don't see what a bare steel rim looks like on a balancer, even brand new out of the box. (not always good) Then throw a tire in the mix... Performance radials are usually good, P are tollerable, LT's are worse, then bias are usually horribile!

Bla bla bla... anyway...

I believe the truck has Goodyear Wrangler MTRs - which I believe is an LT tire. I'm not going for perfect here, just going for a "non death ride experience"

-Greg

[Mkcustums]

That wasn't aimed at you at all, that was just a sarcastic comment is all. It was more of a hit at the tollerances of companies than anything else.

Totally no offense towards you at all!

[Mkcustums]

Oh, and your truck looks really good by the way! The doors are awesome!

[gcsupraman]

Originally Posted by Mkcustums

Oh, and your truck looks really good by the way! The doors are awesome!

Thank you. I love the truck - just need it to drive straight! But I think i'm almost there. And I wasn't offended at all by your comment!

Thanks again for your help. I think unless Longhair has any objections I am going to order some shims and adjustable ball sleeves to get it perfect.

-Greg

[Mkcustums]

I haven't done an alignment in a long time, so to get it exact isn't my thing. I let my friend dial them in for me these days. I was just hoping to trouble shoot a few ideas to maybe help out.

If anyone reads this thread I would appreciate it if they could offer you more info, anything at this point I think will help.

[TheWhiteElephant]

Have you checked your steering column? How's the rag joint? Does the truck look like it has ever been in a wreck? If it is off that much, maybe a spindle is bent?

[propanemudtruck]

If you're talking caster, I always remember that by the motion of casting (degree that your upper ball joint is in front of or behind the lower ball joint. If the axle is 2° off on one side compared to the other, I'd get an angle finder on each side while the truck is standing still on a level surface. There's no shackle or bushing that will cause this on a solid axle truck. It's gotta be in the axle itself. After all, you're measuring the two ends of a welded tube...

[Mkcustums]

Originally Posted by propanemudtruck

It's gotta be in the axle itself. After all, you're measuring the two ends of a welded tube...

Yeah, that's very true!

[gcsupraman]

Originally Posted by propanemudtruck

It's gotta be in the axle itself. After all, you're measuring the two ends of a welded tube...

Can you please clarify what you suggest I look for. Or do you believe that it was just poor quality control at the factory?

-Greg

[gcsupraman]

Originally Posted by TheWhiteElephant

Have you checked your steering column? How's the rag joint? Does the truck look like it has ever been in a wreck? If it is off that much, maybe a spindle is bent?

Steering column feels good as does the rag joint. With the vehicle running, I can twist the input shaft and everything looks solid.

It's hard to tell if the truck was ever in an accident. I bought it from the original owner (fire department) and it had 12,000 miles on it when I bought it. Looks straight and I don't see anything obvious that is bent.

The steering has been an issue from day 1 and I have been replacing front end parts left and right that probably didn't even need to be replaced!

This is a great discussion on caster - probably one of the most informative for 4x4's I've seen. Thanks for your continued help - hopefully this thread will help others as well

-Greg

[propanemudtruck]

I'm thinking if the caster is off then one of the welded knuckles is out of tolerance and was before welded. the best and easiest fix, find another axle housing. Any spot you can use for reference on the top of each knuckle like where the ball joint mounts and run the angle finder on both sides. If they're off it'll tell you without much confusion.

[gcsupraman]

Originally Posted by propanemudtruck

I'm thinking if the caster is off then one of the welded knuckles is out of tolerance and was before welded. the best and easiest fix, find another axle housing. Any spot you can use for reference on the top of each knuckle like where the ball joint mounts and run the angle finder on both sides. If they're off it'll tell you without much confusion.

Propane,

Ok - I went to the truck and did a closer inspection on both knuckles and looked where they are welded to the axle tubes. Nothing obvious - both appear to be factory welds and I don't see any obvious bends on the knuckle or axle tube.

I took a tape measure and measured from the center of the upper ball joint to the eyelet bolt for the front spring. 23 5/8's on the left side and 24 1/8" on the left side - off 1/2" between the two sides. This number indicates that on the right side of the truck, the upper ball joint is farther towards the rear of the truck than the left side. I assume this would confirm my 1.1 degree left and 3.1 degree right alignment numbers.

It appears as though the only way the caster could be off this much on one side is (to your point) a bent knuckle, a bent axle tube, or it was initially welded incorrectly at the factory when the truck was built.

Is it possible to cut off the knuckle and reweld? - I can't believe the easiest thing to do is source a whole new housing.

-Greg