argh, alignment=good, still pulls

[gavin]

ok so the print out from my last alignment (Friday) does show the rear, I was just a bit of a tard and didn't pay attention.

Currently caster is at +4.0* on dri side, and +4.6* on pass. side.
Shouldn't those be equal, or atleast closer to the same since the pass. side is easily adjustable? preferably at +4.2* which is right in the middle of the OEM allowed specs?

 

[V8BoatBuilder]

ok so the print out from my last alignment (Friday) does show the rear, I was just a bit of a tard and didn't pay attention.

Currently caster is at +4.0* on dri side, and +4.6* on pass. side.
Shouldn't those be equal, or atleast closer to the same since the pass. side is easily adjustable? preferably at +4.2* which is right in the middle of the OEM allowed specs?

I'm not sure. But what I am sure of is that a little experimentation with your pass side upper a-arm is most likely your best bet here.

 

[gavin]

I'm not sure. But what I am sure of is that a little experimentation with your pass side upper a-arm is most likely your best bet here.

thanks for the quote from that site, too. You know, that was one of the sites I looked at, but didn't pay attention to anything except the thrust angle explanation since I assumed it was the issue. Apparently there's a good chance it is not.

the part that confused me, is that it said it will pull to the side with less positive caster. Yet my pass. side has MORE pos caster, and is the side that's pulling.

argh... I'll start with Brandon's suggestion of adding more caster to the pass. side. Which would mean... making it lean farther towards the rear. I think.

 

[V8BoatBuilder]

I'll start with Brandon's suggestion of adding more caster to the pass. side. Which would mean... making it lean farther towards the rear.

Yes, positive caster means that the upper balljoint is behind the lower ball joint.

 

[gavin]

I'll give it a shot and see how it drives tomorrow.

 

[gavin]

well there sure wasn't much room for adjustment.
I think I got maybe barely a half turn on the caster adjustment bolt, and I can't tell if it even moved the 2nd piece of the UCA.

 

[storlied]

I'm pretty sure it was you who said you had your TT pretty much maxed, I've been told by a few techs that after a certain point getting it aligned is near impossible.. and if pushed far enough can cause other alignment issues after everything settles. (I'm not sure on the validity of this..) but just a thought... do you think it would help at all to lower the TT just a bit within a less stressful position and see if an alignment can get the numbers closer? I could be way off, but it's just a thought. Logically the TT isn't gonna affect anything but camber as far as I know.

 

[gavin]

I'm pretty sure it was you who said you had your TT pretty much maxed, I've been told by a few techs that after a certain point getting it aligned is near impossible.. and if pushed far enough can cause other alignment issues after everything settles. (I'm not sure on the validity of this..) but just a thought... do you think it would help at all to lower the TT just a bit within a less stressful position and see if an alignment can get the numbers closer? I could be way off, but it's just a thought. Logically the TT isn't gonna affect anything but camber as far as I know.

I have made way too many changes to the TT over a few years, where I have it at now I am sure is not near the "max" 2".

although I can say that I really don't know exactly how much height I got from it. And my steering was not this bad after the last time I touched the adjuster bolts and got it aligned, which was I don't even remember when.

 

[storlied]

You change out uppers and lowers when you did your maintenance? I don't just mean the balljoints either... did you change the arms? Maybe one of them is bent just slightly enough to cause this problem? Kinda like Turdle's lift cross member.. you can hardly tell its bent on one side but there it is.

 

[reserved50]

your toe is off in the rear like I said, I also said the rear axle might be steering the vehicle from the back since your rear toe is out (like a monster trucks), anyways since this obviously isnt going to pan out just tell the alignment shop to change your rf caster to 6-7deg positive and possibly decrease the caster on the lf if it can even be adjusted that far. Just changing the caster without an alignment after will not work. This is all trial and error and might end up costing a few hundred dollars until it steers straight if you are going this route.

 

[gavin]

your toe is off in the rear like I said, I also said the rear axle might be steering the vehicle from the back since your rear toe is out (like a monster trucks), anyways since this obviously isnt going to pan out just tell the alignment shop to change your rf caster to 6-7deg positive and possibly decrease the caster on the lf if it can even be adjusted that far. Just changing the caster without an alignment after will not work. This is all trial and error and might end up costing a few hundred dollars until it steers straight if you are going this route.

would 5/100 of a single degree cause a major pull? doesn't seem like it, to me.
and as I said in a previous post, pass. side cannot have any more positive caster added as it's already maxed. And the dri. side isn't adjustable without also screwing with camber.

You change out uppers and lowers when you did your maintenance? I don't just mean the balljoints either... did you change the arms? Maybe one of them is bent just slightly enough to cause this problem? Kinda like Turdle's lift cross member.. you can hardly tell its bent on one side but there it is.

UCA's were replaced 3+ years ago. LCA's were replaced.... last summer? September'ish. The LCA's were replaced without touching the torsion bar adjustment bolts. No noticeable bends were in the LCA's.

 

[reserved50]

I dont know your setup but you can buy camcentric adjusters that slide the upper arm around on both sides to adjust camber or caster, anyways. Your rear toe is off .21deg total, if it was camber it wouldnt make a difference, Im not going to convince you to have the rear alignment repaired but I also didnt drive your vehicle to tell you that is the problem. Anyone looking at your sheet can just tell you the obvious then go from there. The front caster is just a band aid, kind of like having an inoperative headlight on the right side and adjusting your left one so it points to the right but ignoring the fact that the bulb might be burnt out.

 

[gavin]

I dont know your setup but you can buy camcentric adjusters that slide the upper arm around on both sides to adjust camber or caster, anyways. Your rear toe is off .21deg total, if it was camber it wouldnt make a difference, Im not going to convince you to have the rear alignment repaired but I also didnt drive your vehicle to tell you that is the problem. Anyone looking at your sheet can just tell you the obvious then go from there. The front caster is just a band aid, kind of like having an inoperative headlight on the right side and adjusting your left one so it points to the right but ignoring the fact that the bulb might be burnt out.

one said has positive toe, one side has negative toe. Which do negate, right? FWIW, the last print out shows dri. side have +0.10 toe, pass. side has -0.15 toe. So the total toe would be -0.05, no? Hence the print out showing Total Toe of -0.05* for the rear.

as for repairing the rear alignment issue... as I've stated, I don't know exactly when the issue really started. And as I've also stated, it may be due to the rear junkyard axle that is currently on my truck, which was swapped in last year. I still have the original rear axle that was in my truck. How can rear toe issue be "repaired" short of replacing the axle housing? Obviously the alignments should be able to compensate for it, but for whatever reason it hasn't been, I guess?
Currently the rear toe is +0.10 on dri side and -0.15 on pass side. Bent axle tubes a possibilty of that, correct?

unfortunately I cannot seem to find any of my alignment printouts prior to the axle swaps.

 

[reserved50]

your wheels basically point in this direction

| | front

\ \ rear

Im not sure how much of an affect this will have on your pull, but it will make the front of the vehicle turn to the right, try this, measure from the center of hub to center of hub on the left and right side to get the wheelbase, if theres more than roughly 1/4" of difference somethings very wrong, Im just guessing the entire axle is sitting at an angle since the toe seems to be equal, I dont know what else to suggest maybe someone else can.

Only two negatives or two positives equal on both sides will cancel out.

 

[gavin]

your wheels basically point in this direction

| | front

\ \ rear

Im not sure how much of an affect this will have on your pull, but it will make the front of the vehicle turn to the right, try this, measure from the center of hub to center of hub on the left and right side to get the wheelbase, if theres more than roughly 1/4" of difference somethings very wrong, Im just guessing the entire axle is sitting at an angle since the toe seems to be equal, I dont know what else to suggest maybe someone else can.

Only two negatives or two positives equal on both sides will cancel out.

yeah.... as I was vacuuming (haha) I was thinking about it, when it clicked that one side toed in and one side toed out would mean both sides are pointing in the same direction.

but... so here's the kicker.
toe is pointing the rear tires to the left. But, thrust angle shows the axle assy itself is pointing to the right. Granted, not the same amounts, but those 2 would essentially cancel each other out to an extent. right?

anywho; it makes me think there's something wrong with this axle assy. It was an old junkyard unit, but the R&P looked good.

also found an old, unkown-dated printout. Has to be from when the original axle was still in. Shows both rear's having a slight negative toe, and a thrust angle of -0.01.

every other printout I have, which are all after the swap, shows one side having negative toe while the other side has positive toe. All but 1 show negative toe on the left and positive toe on the right. The 1 shoes positive toe on the left and negative toe on the right.

so.... in the end.... I believe the issue most likely started after my axle swap, and is due to the rear axle assy.

 

[reserved50]

I dont remember what neg or pos thrust angles mean without looking them up, but it could mean you have bent leaf springs or brackets etc. If its not that, the axle assembley is bent, I dont know why the alignment shop didnt clue in or tell you at the time. 5.0 explorers also have control arms on the sides of the frame to keep the axle straight, if you bend those it'll move the axle. All I know is if its not the brakes or tires you need to do something about how the axle sits or the axle itself first. The rear axle measurement shouldnt shift by more than about 5% tops if you are saying they did after you swapped the axle and the readings after the swap also varied from each other, somethings wrong.

 

[gavin]

I dont remember what neg or pos thrust angles mean without looking them up again, but it could mean you have bent leaf springs or brackets etc. If its not that, the axle assembley is bent, I dont know why the alignment shop didnt clue in or tell you at the time. 5.0 explorers also have control arms on the sides of the frame to keep the axle straight, if you bend those it'll move the axle. All I know is if its not the brakes or tires you need to do something about how the axle sits or the axle itself first.

The angle between the thrust line and centerline. If the thrust line is to the right of the centerline, the angle is said to be positive. If the thrust line is to the left of center, the angle is negative. It is caused by rear wheel or axle misalignment and causes the steering to pull or lead to one side or the other.

Since my thrust angle is positive, that would mean the axle is facing the right, relative to the frame.

I'm especially surprised since they always test drive the vehicle after the alignment.

the OEM traction bars have been removed due to add-a-leaf and shackles, they were no longer long enough. Plus the particular axle housing in my truck came out of a 4.0 so it didn't have the mounts on the housing.


at this point, I'm just going to work on getting gear sets to regear the other axles I have sitting in my garage. Then worry about it if I still have issues after I put those back in.

 

[storlied]

A lil off topic: Woah woah.. I didn't realize AAL calls for killing the traction bars. (I might have to call that off... idk.. depends on the clearance once we do the lift..) I like the traction bars because I've read about axle wrap, I believe it was called.. but at the same time... how much do these affect articulation? Was stability/handling changed much when you took them off after the AAL?

I hope the gear swap goes well, I'll also be doing this down the line.

 

[V8BoatBuilder]

I didn't realize AAL calls for killing the traction bars.

1) I ran Warrior shackles and a single AAL with my traction bars for years without problems, took them off when I swapped in an axle from a V6 (no bar mounts) and went SOA.

2) I'm now running SOA w/4.56 gears (way more chance for axle wrap!) and no traction bars and have not had any axle wrap issues, yet.

 

[storlied]

Good to know, thank you. Any comments on articulation limits?