Author Topic: DIY Alignments  (Read 2240 times)

Shovel

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DIY Alignments
« on: October 06, 2017, 12:34:39 PM »
Gen 2 Monteros have the following alignment specs according to what I was able to find:  (will update if superceded by actual Mitsubishi data from a legit source)

0.66 Positive Camber +- 0.5 
0.14" Toe-in +- 0.14"  (that is, inches measured from the front of the tire not degrees)
3.00 Positive Caster +- 1.0

That means the top of the tires should lean out slightly past the bottom of the tires (but almost imperceptibly so) and there should be almost no toe but what's there should be in not out,  and the upper ball joint should lean behind the lower ball joint so that there's a 3 degree angle from vertical when viewed from the side.      Use the googles if you need to know what these things mean, I'm writing with the expectation that the terms are understood and that you're already pretty decent with a wrench so if any of these things don't make sense  it's time to either learn the hard way or get out your wallet and pay somebody. 


So how do you get those precise looking numbers at home?

Cheap tools and cheaper tricks.    You'd be surprised how good a job you can do of this,  in fact fuck paying $80 for a "toe only" adjustment at the tire store... I promise no tire stores are doing caster/camber adjustments on a Gen2 Montero.   

Let's get caster out of the way first:

You probably won't have to mess with caster unless your Montero was in a wreck or something it's going to be pretty much within the specification already.    There are ways to adjust caster but you have to be careful with that, it gets complicated kind of fast and yes you can do it,  NO this forum post from an internet stranger doesn't want to be responsible for your growing pains if you try to learn that magic on your own.     Just measure your caster,   confirm it's within spec and move on.

Camber:

Get one of these tools,  they're about 15 bucks online.  Including shipping (ebay, amazon prime..)    There are fancier and presumably more accurate ones I guess, but I didn't feel the urge to step up for my purposes. 

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You can google alignment camber tool .   

It should go without saying that you should be doing the remainder of this work on a level, flat, clean concrete surface because we're going to be dealing with measuring stuff and if you're parked out in your mud puddle gravel driveway it might throw some of those measurements off a bit. 
 
Take off your front wheels and remove your front shock absorbers.   Yeah that's a pain in the ass, the other alternative is go find a frame shop and pay them money to do it - no shame in that but this topic is for the DIY'er.

Use blocks of wood or jackstands or whatever you like to safely hold up the front of your vehicle by the lower ball joints or as far outboard on your lower control arms as possible.      This is because you want to have the weight of the vehicle on the suspension so it compresses to the normal place it would be with the tires on the ground.    Remember that the lower control arms move in an arc so you'll have to support your vehicle in such a stable way that you can jounce the vehicle a bit to shift the weight against lateral friction and really settle down to actual ride height or pretty close to it.     

Point your steering straight. 

Now stick  your magnetic alignment gauge to the disc brake with the bubble dealie facing level up.   There might be a thumb adjust wheel on it,  be sure to adjust that so the movable level carriage is flush with the actual tool body,   since we're not trying to achieve any weird racing camber nonsense.         Read the bubble.   Neat.

Now you can use regular tools to loosen (but not remove) the nuts that hold the upper control arm pivot bar,  and insert or remove shims as needed to achieve the camber you want.   If you're doing round shims (precision thickness washers)  you might still want to use saddle shims to discover the right shim stack height, then just measure that and duplicate that height with your round shims.      Also if you're doing round shims, loosen both front and rear bolts but only remove one at a time for inserting the round shims,  or you'll be sorry that you didn't heed that advice. 

Good?    Tighten to appropriate torque spec (don't remember the numbers, will update later when I find them) . 


Toe:

Put all your stuff back together,  shocks and tires back on,  back on the ground and be sure to move the vehicle back and forth a foot or two so that arc the control arms move when the suspension travels isn't putting tension on the tires.   

Now find a really consistent element on the tread of your tires,   a place that's exactly the same on either one.  Ideally it will be near the outer edge of the tread but it doesn't really matter where as long as it's really consistent.       

Use a plumb bob or a laser pointer to measure from that spot on the extreme front of your tire straight down to the ground,  and mark the ground there with a sharpie marker, crayon,  blood of your enemies, whatever.         Do the same thing from the extreme rear of the tire,  and do the same thing on the opposite side of the vehicle.   

Now measure the distance between those marks with a tape measure.       Adjust the toe as needed.     Repeat as needed.   

Also if your steering wheel isn't centered you'd be wanting to take that up by balancing which side you're adjusting more, or less when setting toe.     

That's it.      A $15 specialty tool,  a plumb bob you could make out of a key and some thread or you could use that laser pointer you're always shining at the cat's bumhole,  a tape measure and a good flat clean surface to park on.   

Hope this has been helpful. 



RyanY

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Re: DIY Alignments
« Reply #1 on: October 06, 2017, 06:23:41 PM »
Your procedure for measuring toe is ballpark close, but will vary depending on the size of the tires on the vehicle. Using your procedure, the 30.5" stock tires will yield a different toe setting than a set of 35" tires would.

Shovel

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Re: DIY Alignments
« Reply #2 on: October 06, 2017, 08:19:36 PM »
If we're splitting hairs, 0.00" is within the acceptable range  8) 


MudRaider

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Re: DIY Alignments
« Reply #3 on: October 07, 2017, 05:29:00 AM »
Your procedure for measuring toe is ballpark close, but will vary depending on the size of the tires on the vehicle. Using your procedure, the 30.5" stock tires will yield a different toe setting than a set of 35" tires would.
I'm not understanding why tire size would affect it. It would seem the static settting would be the same, regardless.

Shovel

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Re: DIY Alignments
« Reply #4 on: October 07, 2017, 05:56:33 AM »
Since the specified measurement is a distance quantity from a point on the tires vs. the center of the tires (pivot point) the radius of the tire affects the resulting angle.

For a 30" tire,  0.14" of toe in is a 0.535 angle while the same toe measurement on a 35" tire is 0.458 

The acceptable range includes 0.00" of toe, which would result in a 0.00 angle without respect to tire diameter.     

I doubt anybody outside of a professional race driver at the top of the profession could realistically tell the difference between 0.535 and 0.458 all else equal;  I've always just measured from the front and rear edges of the tire - doubling the measured range - and then aimed for as close to zero toe as possible while trying to bias any error slightly inward.    Differences of a tenth of a degree are going to produce less perceptible effects than the difference in tire temperature from parking with one side of the truck shaded and the other side in sunlight. 

RyanY's complaint is technically accurate but practically I don't consider it significant beyond just something to keep in the back of your head when deciding where to bias your expected inaccuracies.  :D

MudRaider

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Re: DIY Alignments
« Reply #5 on: October 07, 2017, 10:58:35 AM »
Roger that.  Thanks for the clarification.

RyanY

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Re: DIY Alignments
« Reply #6 on: October 08, 2017, 04:17:56 PM »
You're absolutely right, I hadn't really considered how insignificant the difference due to tire size would actually be.   

JohnnyBfromPeoria

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Re: DIY Alignments
« Reply #7 on: October 16, 2017, 10:14:22 PM »
Toe check: Also, instead of attempting to find a consistent place on your tires to measure from, try this trick: Use two bottle jacks to jack up both front wheels under the lower control arms so they are sitting loaded, but able to spin. Get a can of white spray paint and hold it with the bottom of the can on the ground so it stays in the same place, pointed at the tire, a couple of inches away so you get a narrow line of spray, spin the tire by hand and spray the paint. Now you've got a pretty easy-to-use line to check toe with. That's how my preferred alignment shop does it, but with Eric's method above (and I saw his gauge in his garage - neat tool), I may never need them again.

John B.
AZ Crew/East Sider/Former 14th St Crew
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