So the new tires are Nokian 235/75R15 109TXL, I set them at 35 psi.
That's probably a bit too high. What is their maximum PSI rating on the sidewall? Most of us are settling on about 25psi in the front and 20-22 psi in the rear. Going too far off of that often results in wandering or darty feeling steering.
Since it's easy (and free) to test, I recommend dropping them 5psi in the front and 10psi in the rear to see if it feels any different. Then play around from there.
I also mounted them on recently purchased Indy mag wheels.
What size? If they are 8" or wider that might be a bit wide for a 235mm wide tire. If it does still fall within the recommended range, then I guess we can't blame that just yet. But putting a too-narrow tire on a too-wide wheel can give you all sorts of odd feelings on the road.
And changing the width of the wheel compared to the tire often requires twiddling with the pressures again anyway.
In fact, every tire and wheel combo can be different and fiddling with tire pressures is part of the game. Sometimes you fall right back at the same pressure, sometimes you have to change it quite a bit.
Same for toe-in.
The alignment report says that it was set to Chilton specs:
Caster range 2 3/4 - 4 1/4 preferred 3 1/2 P, Camber 1 P - 2 P, preferred 1/2 P, Toe in 1/16 - 1/4 ".
Too bad they only gave you the specs, and not the actual settings. Even though it falls within spec, there are differences to be felt depending on the actual settings.
And unless they charged you several hundred dollars, I'm willing to be they did not actually set/adjust the camber or caster. Just left it where they found it.
Likely as not if they adjusted anything it was just the toe-in. But if they found it within spec they would not have touched that either.
But you can...
I usually recommend to people experiencing odd behavior with their rigs to tweak the toe-in settings a tiny bit each way to see how they like the changes. When I was daily driving mine I would do that every time i put a new set of tires on it. It was quite surprising how much you could feel just a 1/8 turn of the adjusting sleeve. I almost always found that right in the middle was the sweet spot, but not always.
You can easily change the toe-in without measuring just by turning the sleeve with simple hand tools that most (but not all) of us have laying around. A pipe-wrench comes in very handy here.
In the course of recently replacing axel seals, I've done a lot of work on the front end: servicing kingpins and bearings, new shim pack, torquing knuckle rotation to spec.
Good information to know that the knuckles turn within spec. This can be a big deal, so it's nice to know yours are good.
Then the only things left are track bar (which looks original) and steering box - I did at the beginning of this have someone turn the wheel while looking at the front end, and check the box bolts etc. So in choosing between the two, since the axel alignment is off by about an inch, probably that's the one to work on next !
Makes sense. Definitely get some precision measurements off of the frame (not the body, which can shift, or be damaged over time) and make that adjustment.
I've been of the opinion that most people will never feel up to a 1/4" off, but by the time you get to 1/2 and more so at 3/4 inch, it has to change at least some mannerisms. Doubt they'd cause an actual "wobble" like you're experiencing, but a wander? Sure thing.
Another thing to look at is remembering never to trust new parts. Even tires.
If it's acting funny, and wobbles often come from tires (if your use of the word "wobble" is what we're thinking), then simply rotating the tires might give you more clues. Or even fix the problem!
Sometimes a belt is bad inside a tire and under braking or turning the load changes and a wobble makes itself known. So here's where more detail would be good. Is the wobble felt in the steering wheel? Or is the front of the truck pogoing up and down on one side? Is it shifting side to side under different conditions (bump steer basically) or something else?
Definitely go to the trackbar. Since it sounds like an adjustable one is in your future and they're going to come with new bushings anyway, you'll kill two birds with one stone.
Pay particular attention to the upper bolt. If the bolt is original too it's very possible it's rusted down to a point where it should be replaced. This is a common issue and I found mine was rusted badly when the truck was only 6 or 7 years old. You've got almost 50 more on me!
The weld on the lower bolt can crack too, and while it won't fall out because it's fully captured, it will allow the lower one to flex under use and cause a tiny bit of wandering. Re-welding has fixed many for members here.
If your lower and upper are compromised, along with original rubber bushings being worn out perhaps, it's very likely a good bit of wandering is from this.
No way to tell the condition of the steering box from here. You'll have to inspect it closely. And that screw is not to be messed with haphazardly. It's a preload adjustment for initial setup and a tiny bit of adjustment over the years. But not much...
So, trackbar, steering box, tire pressures, tire rotation, and toe-in experimenting are still in your future it sounds like.
Have fun!!!%)
Paul
