2WD C10 Modern/Performance Alignments

[68 TT]

Originally Posted by Portmod7

...One thing I've noticed about toe over the years... If you have toe-in, the front end will usually be very touchy and darty as you turn the wheel. If you have toe-out, it usually makes the front end seem lazy.

I thought it was just the opposite.

[usmcchevy]

Originally Posted by Greywolf200

This is exactly the setup I'm considering. How about some side pics to show the stance and what are your tire sizes?

Thanks,

Current tires are front 255/60R15 and rear 275/60R15.

Just got the new front tires on tonight and this is the best I can do. Tomorrow or friday I'll get some better pics.



I drop her off tomorrow at 7am for an alignment.

[BMERDOC]

usmcchevy, I know I dont even have to ask you to post the results when you get them Robnolimit said he had 8-9 degrees with a 1" inch movement of the cross shaft mounts. So I wanna see what caster spec your 3/4" movement delivers.

[DM Garage]

Here is a great article that should help people understand alignment angles. Keep up the work Nick!

[BMERDOC]

Very good article! Thank you for posting as a PDF so that it doesnt disappear from the thread. Once I started this thread I looked around for little tid bits of info and realized I coulda just posted a bunch of websites to explain the different angles but that woulda bean cheating.

[Greywolf200]

Originally Posted by Portmod7

Won't this increase positive caster?

Love the thread by the way, very good info.

One thing I've noticed about toe over the years... If you have toe-in, the front end will usually be very touchy and darty as you turn the wheel. If you have toe-out, it usually makes the front end seem lazy.

Reading the concerns over thrust angle, if you did find yourself having issues with it because the frame might be tweaked, you might be able to get some satisfaction out of removing the rivets on the trailing arm mounts, replacing them with bolts, and using washers to shim between the mount and the crossmember on whichever side of the truck is too short. Just a thought....

The intent of the modification is to increase positive caster. On Rob's recommendation, I changed from traditional toe-in to toe-out and am very pleased with the results. No effect on straight line driving, but much improved turn-in.

[Greywolf200]

Originally Posted by usmcchevy

Current tires are front 255/60R15 and rear 275/60R15.

Just got the new front tires on tonight and this is the best I can do. Tomorrow or friday I'll get some better pics.



I drop her off tomorrow at 7am for an alignment.

Thanks, that looks really good. I'm not really fond of the frame dragin' types of trucks out there. I'll be running the same size tire all around.

Thanks again,

[Portmod7]

Originally Posted by Greywolf200

The intent of the modification is to increase positive caster. On Rob's recommendation, I changed from traditional toe-in to toe-out and am very pleased with the results. No effect on straight line driving, but much improved turn-in.

I understand the intent, and couldn't agree more. The wording used seemed (to me anyway) to contradict what was being accomplished, just didn't want those that were seeing this stuff for the first time to become confused and wonder if they were missing something.

I believe most of the factory produced geometry isn't designed for people who want to or know how to "drive" their vehicles. Little tweaks here and there can provide much more driving pleasure for those of us who REALLY "drive".

So you say the turn-in is "improved" with some toe-out. "Improved" in what aspect? Is it more responsive to wheel input(oversteer), less responsive(understeer), etc? I am just curious, I LOVE this stuff. The cause and effect of it intrigues me.

[usmcchevy]

Bad news for me.

Camber -.5 drivers side -.8 pass
Caster 5.6 drivers side 0.4 pass

They said when they tried to get more caster out of the passengers side the camber would go positive.
This is the passengers side



Drivers side...normal



I'll be taking it to a different shop next week that has a frame rack

[hairlesshobo]

Originally Posted by usmcchevy

Bad news for me.

Camber -.5 drivers side -.8 pass
Caster 5.6 drivers side 0.4 pass

They said when they tried to get more caster out of the passengers side the camber would go positive.
This is the passengers side



Drivers side...normal



I'll be taking it to a different shop next week that has a frame rack

Damn man, that sucks.

Just wondering, for it to be that far off on one side, wouldn't that almost have to mean that you have a bent control arm? I would imagine that a control arm is the problem and not the frame itself.. or am I way off on that?

Keep us posted!

[usmcchevy]

Originally Posted by hairlesshobo

Damn man, that sucks.

Just wondering, for it to be that far off on one side, wouldn't that almost have to mean that you have a bent control arm? I would imagine that a control arm is the problem and not the frame itself.. or am I way off on that?

Keep us posted!

I've known this truck took a hit and bent the passengers side rail, but I thought all the damage was ahead of the cross member. The control arms are not original to the truck and seem straight. I would think if the control arm were bent over 1"(guess) they would look like pretzels.

[69gmcc10]

usmcchevy, I am sorry to hear that. I was hoping good news from your truck so I knew what to do with mine. Hopefully you get it fugured out and you keep us posted.

[BMERDOC]

usmcchevy, that stinks! Hope you can find the problem and easily solve it.

[BMERDOC]

So I aligned my 325i tonight. Notice how much camber is allowed by the spec. Notice how little caster was dialed in back in those days (for a BMW) . I don't know why mine is closer to negative caster though. Check out the fractional toe! Again, 1/16th postive per side and 1/8th total.
The toe was so far out initially because I had to take off the steering wheel to do some work. When I put it back on I installed it one spline of to the right accidentally. Leveling the steering wheel before setting toe made it look like this.

[hairlesshobo]

Originally Posted by BMERDOC

So I aligned my 325i tonight. Notice how much camber is allowed by the spec. Notice how little caster was dialed in back in those days (for a BMW) . I don't know why mine is closer to negative caster though. Check out the fractional toe! Again, 1/16th postive per side and 1/8th total.
The toe was so far out initially because I had to take off the steering wheel to do some work. When I put it back on I installed it one spline of to the right accidentally. Leveling the steering wheel before setting toe made it look like this.

Just curious, what was the before and after caster numbers on your 325i?
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[BMERDOC]

Caster is non adjustable on these cars. It is possible to swap out the M3 strut plates or some adjustable plates (KMacs, etc). I can use 95 M3 control arm bushings to dial in some more caster which would be the cheapest/esiest route.

[hairlesshobo]

Oh, I didn't realize that. Good info to know.
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[Greywolf200]

Originally Posted by Portmod7

I understand the intent, and couldn't agree more.
So you say the turn-in is "improved" with some toe-out. "Improved" in what aspect? Is it more responsive to wheel input(oversteer), less responsive(understeer), etc? I am just curious, I LOVE this stuff. The cause and effect of it intrigues me.

Hi, turn in is quicker, plowing is much decreased. Not into the oversteer range, but much improved. It's ready to go when your are.

[Portmod7]

Originally Posted by Greywolf200

Hi, turn in is quicker, plowing is much decreased. Not into the oversteer range, but much improved. It's ready to go when your are.

Nice! Thanks for the reply!

[BMERDOC]

So I was aligning a S. Box today. I got my angles up and focused in on the specs. My knees buckled a little!! 8-9° caster! Ha! The camber isn't a crazy spec but who woulda thought that? I must admit, I've always looked at the numbers when I was aligning but never gave them a conscience thought. Now that I'm looking I'm finding some interesting stuff!

[Spla'nin]

As always, thanks for the data Nick ..

[INSIDIOUS '86]

Alright so here's my baseline specs.

Caster drivers side 2.2, 0.4 pass
Camber -0.5 drivers, -0.4 pass
Toe is .45* inward both sides

Not sure if rear camber will tell you anything but
Drivers rear. 0.2, -0.9 pass
Toe is -.50 drivers and 0.70 pass
And thrust says -0.6 ?
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[BMERDOC]

Ok, to start with the rear. Like we talked about in your thread, I don't think you have much to worry about. Unless you find out whats causing it you'll have to live with it.
As far as the front goes, without making mods to the front end my only concern is the caster on the passenger side (0.04) and the toe specs.
Are these baseline settings with all the shims removed? If you try to make passenger caster more positve you make that camber more positive too...no good. Is the suspension nice and tight (ball joints, cross shafts)? You have got to get the initial caster closer to matching your dr's side before any shimming can begin. My thought is that you may end up machining the lower cross shafts to gain more positive camber by drilling the dr's at 3/4" cl and the pass at 1" cl to compensate for the current alignment but I would definately check to make sure you wont be covering up a real problem.

[BMERDOC]

I meant to add that because your dr's rear is toed out and your passenger rear is toed in would indicate the Thrust being negative. So the truck would want to rear steer right causing you to correct it by steering left. Either your frame is bowed so that the right side wheel base is shorter or you have a problem in the rear suspension causing the centerline to aim negative. Are the bushing good in the springs? There may be NO problems at all with the rear end and -0.6 is what its been forever.

[INSIDIOUS '86]

Bushings seem ok. It's got drop hangers and shackles from po so the may not be even side to side so I will measure those. But a long time ago it got curbed on the pass side and I don't know if our licorice soft frames absorb that or just bend. Either way I want to be sure
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