PML - Alignment

[shyamrox]

Hey All,
So I went to get an alignment today, and gave them the specs that are posted in the How-To. They said the specs were great, however when the tech did the work, he couldn't break free the camber bolt to adjust the camber, he said if he had to get it out, he would have to replace the whole UCA. He also mentioned that the camber was fine as is (due to torsion sagging, etc (he also showed me the computer showing me that it was in spec) and he adjusted the toe, etc.

It drives fine... and I've just read online that many folks have trouble with the camber bolts......so is this alignment experience typical?

Thanks!
Shyam

 

[xterror04]

Yes it's very typical... You went to a good shop because some shops won't tell you they couldn't adjust camber... And they will just pretend they fixed it.

If everything it in spec then you will be fine!

 

[shyamrox]

That's a relief!! They seemed like great guys!

Thanks!!!

 

[MichaelS75]

Same thing happened to me. The shop was able to get everything OK except the camber. Drives great!

 

[robcarync]

Fairly typical. Just keep an eye on the tire wear and if it starts to get uneven, you may want to rotate and start to explore other solutions.

Most tire wear is caused by excessive toe in though....so you should be good!

 

[TJTJ]

Hey All,
So I went to get an alignment today, and gave them the specs that are posted in the How-To. They said the specs were great, however when the tech did the work, he couldn't break free the camber bolt to adjust the camber, he said if he had to get it out, he would have to replace the whole UCA. He also mentioned that the camber was fine as is (due to torsion sagging, etc (he also showed me the computer showing me that it was in spec) and he adjusted the toe, etc.

It drives fine... and I've just read online that many folks have trouble with the camber bolts......so is this alignment experience typical?

Thanks!
Shyam

He would not need to replace the UCA to change the camber bolts out. The bolts holds the UCA on, so, the UCA comes off, but, back on again.

If you sagged/are at stock height, you don't HAVE a PML, so he's telling you you are at stock height, so stock alignment specs work.

Did you WANT a PML?

 

[shyamrox]

Haha I WANT a PML - All I can say is that my bump stop gap is at .5"....sooo not sure what else I could do short of swapping out the UCA.. The camber was slightly off but still in spec, as he put it.

I can definitely notice a difference in lift... I have before and after pics in my build thread..

 

[TJTJ]

Haha I WANT a PML - All I can say is that my bump stop gap is at .5"....sooo not sure what else I could do short of swapping out the UCA.. The camber was slightly off but still in spec, as he put it.

I can definitely notice a difference in lift... I have before and after pics in my build thread..

OK, then, we just need to reconcile him telling you that you are at stock height "Due to sagging", while you say you are not.

Is it possible he said that to get out of doing the camber bolts, and send you on your way?

 

[shyamrox]

He would not need to replace the UCA to change the camber bolts out. The bolts holds the UCA on, so, the UCA comes off, but, back on again.

I think his point was that in order to get the camber bolt out he would have to torch/cut the UCA and have to replace it, he said he could do it, but the camber wasn't so out of spec that he would recommend that I spend the $$ to do it.

 

[shyamrox]

OK, then, we just need to reconcile him telling you that you are at stock height "Due to sagging", while you say you are not.

Is it possible he said that to get out of doing the camber bolts, and send you on your way?

Yea - its possible... he showed me the screen and gave me print outs, i could probably share them later tonight and get your input...

 

[TJTJ]

You don't need to torch the UCA, just the bolt itself.....they rust weld all the time, and, you cut off the bolt...not rocket science.

That's a SECOND thing he told you that is in conflict with other information.


For example, when doing 3" SLs, when we go to replace the UCA, the camber bolt is typically rust welded....so, if planning a SL, we get the camber bolts, nuts and washers before starting...knowing we will most likely cut the bolt off....and use the new bolt to replace it.

I have never had to cut off a UCA though, ever.

 

[shyamrox]

Sorry, I might be mistaking what he told me - I'm pretty new to this stuff... But yes I agree, the bolt was rust welded, and he didn't do what was required to break it free. Should he have? is it typical that shops will do this when you pay for an alignment?

 

[TJTJ]

Sorry, I might be mistaking what he told me - I'm pretty new to this stuff... But yes I agree, the bolt was rust welded, and he didn't do what was required to break it free. Should he have? is it typical that shops will do this when you pay for an alignment?

Its fair to charge you more for repairs needed to perform an alignment.

But, a good shop will replace the bolt and be ABLE to do an alignment.


As you have your print out, a key to look for is the camber.

When you lift an IFS rig, the tires swing in and down, so the tops of the tires are tilted outboard:

\-----/

(As viewed from the front of the truck)


You WANT the camber to show the tires back upright again:



[-----]

(Same view)



Try to guess what that darn camber adjustment bolt is there to adjust?







Suggested QA/QC test - find a "thing" that's 1/2" thick, like a short dowel, or a sausage, whatever...as long as its 1/2" thick.


Pass it through your upper bumpstop gap, and see how much room it has to get through that gap (They are notoriously hard to gauge by eye, due to the angle).

Take a pic of the upper bump stop gap too, from a few angles.

 

[shyamrox]

Thanks TJ! Will do - When I did the front I used a couple thick paint sticks (the kind used for 5-gallon stirrers) taped together, measured at just a hair under .5" - i cranked the bars until I could just barely get it between the bumpstop and the UCA.

I'll also try to remember to post up the print outs they gave me.

Thanks!

 

[TJTJ]

Sounds plan-like.



Essentially, the t-bar adjusters are to compensate for sag over time....to allow you to restore lost ride height.

If your ride height is "restored" as high as it can be adjusted, it can't ALSO be sagged.

 

[robcarync]

If the stock bolts are fused in the bushing, you may cut them out, but not be able to get the cut part out of the UCA even after the UCA is removed. That would make replacing the UCA necessary.

What happened, is that even with the PML, the lift was NOT high enough to throw your camber off TOO BAD. It is in the "GREEN" technically, but not optimal. The tech is talking about sagging etc just making stuff up to explain why it is in the GREEN. The real reason it is still in the "GREEN" is that the computer has loosey goosey wide spec ranges, and the PML is not a very aggressive lift.

You will eventually want to take care of it and try and dial some camber out, but I don't think it is incredibly urgent.

Who knows, fast forward another 6-12 months and you may be drooling at the thought of UCAs for a higher lift

 

[shyamrox]

Haha I'd already be considering it but I don't have the tools or know how to break loose the camber bolt!


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[TJTJ]

Haha I'd already be considering it but I don't have the tools or know how to break loose the camber bolt!


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Its settled then, do a 3" SL, as you get new UCA anyway, and have at it.

We typically sawzall off the bolt along the UCA bushings, and then, if need be, drive the bolt out of the bushing. I have never had to replace the UCA, as it can be driven out, but, I could see it if someone didn't have time to Kroil it, etc, beforehand.

My personal ones came off w/o even cutting off the bolt, but that's with a lot of advanced PB Blaster, etc. I always get the camber bolt stuff in advance, just in case though, as the others I see don't always get enough soak time.

 

[shyamrox]

We need an awesome how to on installing the 3" sl UCA


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[TJTJ]

We need an awesome how to on installing the 3" sl UCA


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Its just like the PML combined with the existing AAL how-to...with the addition of changing the shocks and replacing the UCA when you get the bolts out.

 

[robcarync]

We need an awesome how to on installing the 3" sl UCA


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http://www.clubxterra.org/forums/showthread.php?t=11604

Step 1

Sawzall the UCA cam bolts out...and replace them when you put new control arms in. It was much easier and faster for me to just cut them out instead of hoping that they could be removed.

https://www.4x4parts.com/nissan/xterra-cam-bolts-p-6123.html


Step 2

Removing the upper ball joint is tough...but use a pickle fork or ball joint press...torch, big hammer, etc:

http://www.clubxterra.org/forums/showthread.php?t=38088

http://www.clubxterra.org/forums/showthread.php?t=30567

Step 3

Remove the old UCA, while removing any ABS sensors or brake lines etc that are strapped to the control arm

Step 4

Bolt up the new UCA using anti-seize compound or grease on the bolts and bushings.

Step 5

Re-adjust your torsion bars to get some more lift. You may need to Re-Index (see How To in my signature). The UCA does NOT give you lift...they simply allow more room to adjust your torsion bars and still get a green alignment

Step 6

Get an alignment quick!


This is much easier said than done. Most of the time it spend beating up on stuck hardware or ball joints.

 

[shyamrox]

Its just like the PML combined with the existing AAL how-to...with the addition of changing the shocks and replacing the UCA when you get the bolts out.

TJ - You're an enabler - feeding my mod bug! LOL I think I'm going to stick with just the PML for now at least until I get bored and need something new to do


I attached the Snapshot of the specs they did the alignment to... I won't be able to take pics of the bump stop gap until I get home later tonight.

 

[robcarync]

TJ - You're an enabler - feeding my mod bug! LOL I think I'm going to stick with just the PML for now at least until I get bored and need something new to do


I attached the Snapshot of the specs they did the alignment to... I won't be able to take pics of the bump stop gap until I get home later tonight.
View attachment 2290

The left toe measurement would be a tire wear issue. 0.2 and 0.4 isn't too bad for camber...0 is better, but it shouldn't be too much of an issue.

Camber and caster are both adjusted with those bolts, so those can't be adjusted until new bolts are used. Your toe is set to spec now, so you should be OK as far as tire wear.

 

[shyamrox]

Thanks! sounds similar to what the tech told me

 

[shyamrox]

It is possible to figure out, based on that spec that I uploaded, whether I could get a bit more lift out of bump stop gap and still be ok with resulting camber? Or should I just leave it all alone?

I have unlimited alignements for the year, (yes I paid the extra $20 for it knowing full well that I can't leave things alone haha)

 

[robcarync]

At 0.5 * camber, I would not go higher....especially since you can't adjust camber with your bolts the way they are

 

[shyamrox]

Here a dumb question. Is the left side considered the drivers side or the passengers side?

(Looking at the front versus sitting in the drivers seat)


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[robcarync]

sitting in drivers seat

 

[TJTJ]

I hate trying to read stuff like this on my phone, but, it LOOKS like you have some camber adjustment to do yet, once you get new bolts, etc...plus, you have waay too much toe in.

For a PML, you want ~ 0.08" per side, for a TOTAL TOE of ~ 0.16" (You have ~ double those specs)

You do want more caster on the right than the left, about a 0.3 difference, you have ~ 0.2 difference in the correct direction, but, you have a lot of caster, in that the number on the right would be better if ~ 1.2 instead of 1.6 for example.

So the excess toe tends to hurt mpg and tire wear, and the responsiveness to steering input...while increasing straight line stability (I you were skiing, you would be described as "snow-plowing").

Caster in of itself tends to increase stability, and, also hurt responsiveness to steering input. (A "Chopper" style motorcycle's front wheel has a lot of caster, while a cafe racer would have almost none...as an example)


So, here's the situation - You really can't change one thing w/o the others changing too, as the parts are connected. You plan on getting new bolts and adjusting the camber, to get the tires upright again...so, when you do that (Soon, before the front tire wear sets in) - you can have it all re-adjusted to the PML spec.

If you wait too long, the outer edges of the front tires will get worn down.

Once that happens, even after set upright and the toe is corrected, etc...whatever wear pattern you have will tend to continue anyway (Tires "Take a set" typically).

So, do it soon before you ruin the front tires.

 

[shyamrox]

Sorry to keep dragging this thread on and on - here's another question... If my bump stop gaps are already at .5", and I didn't get the full lift of the PML....such that the camber on my wheels didnt change so dramatically, that I can get an alignment to the PML spec... what is the solution to get the full PML height? replace the torsion bar to one that hasn't "sagged"?

Just asking for now...not likely something I will actually do for the time being...

 

[Prime]

As has been brought up before, every X is a little different. Don't be obsessed with the .5" bump stop gap. It's not an exact science. Crank it until you are happy with the way it drives. Keeping in mind that it may have to come back down in order to be properly aligned.

The only thing you want to avoid is sitting DIRECTLY on the bump stops.

 

[robcarync]

TJTJ...he has .32 degrees of total camber, which should be the equivalent of 0.16 inches if I recall correctly. I know I looked the spec up in the FSM a while back and found that .32 degrees on each side was the degreed version of inches.

The toe in has more of an impact on tire wear in my experience. Having your tires angled in too much will constantly scrub the outside edge of your front tires as you drive.

The caster angle will give you steering stability. Think of a chopper motor cycle and how the handle bars are angled. It allows for a smooth turn having the tire that far out in front of the bike. Then, compare that to turning on...a unicycle where the turning tire is immediately below you. Tight sharp turning and if you turn too fast, you can flip over on yourself. You typically want the right front tire to have the most caster as possible, and you adjust the left tire to have slightly less caster. This compensates for road crown, as most roads slope to the right for drainage. Having the left tire adjusted back causes the vehicle to pull left slightly on a perfectly flat surface...which means it will track straight on most roads.

The camber just means the angle of your tires relative to the flat ground. Is the outer edge leaning more outboard than the bottom edge on the ground? That is positive camber. Ideally, you want zero camber, which means the tire sits perfectly perpendicular to the ground and your tire tread is perfectly flat and center on the ground. This can cause uneven tire wear as it leans more on one side of the tread, but since the angle of the tire in this way does not increase rolling resistance (only toe in does...as both tires point inward toward the middle of the vehicle), there is not a huge increase in force/load on the tire.


As Prime said, it is not an exact science. Swapping a new torsion bar won't increase lift height. The bump stop gap defines the angle of the upper control arm. This upper control arm angle defines how high the truck is sitting. A stiff torsion bar adjusted to a 0.5" bump stop gap will be the same height as a saggy torsion bar adjusted to 0.5" bump stop gap....you just might have to adjust one bar more to get there.

The 0.5" gap is not a hard rule. As long as you can get a good alignment, you can lift it however much you want. I would not lift any more until you get your cam bolts taken care of, though. I would also do that pretty quick.

 

[shyamrox]

Thanks for the info all! I will call them back to see how much it would cost to get the cam bolts cut off and replaced to get proper camber on the tire.