2WD C10 Modern/Performance Alignments

[tinydb84]

The bolts on my 75 are 9/16''

[67_C20Pres]

Originally Posted by BMERDOC

The frame bolts that retain the upper control arms are actually 1/2". The part number for the HF shim kit is 67585 and works perfectly.
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Link = http://www.harborfreight.com/144-pie...ent-67585.html

[BMERDOC]

Yup. Thats the one. On a side note, I got an 09 Silverado not too long ago. I'll be looking into doing some alignment improvements soon. Both before and after a 4/7 drop.
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[pablo101]

Here's the Alignment sheet

[BMERDOC]

You guys are using a Hunter machine. See if this link helps dial it in a little better.

http://67-72chevytrucks.com/vboard/s...d.php?t=582187
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[eightbanger]

I live in the U.K so getting stuff done on my Truck is just that bit harder, the shop I go to will do my Toe, because as luck would have it it's on their computer, but they will not touch the Caster/Camber. So I just had my Toe done today as the truck was pulling to the right, I've had to mess with the camber/caster at home on the drive but still don't really get it, anyway drove out of the shop and its still pulling to the right.

Frustrated at my lack of understanding of technical stuff, im going to have to post this and ask, whats it telling me?

[BMERDOC]

First thing's first....swap the front tires side-to-side. If steering is neutral or pulls left you have a tire issue. Hopefully it'll steer straight. Critiquing the other angles if I may, your caster is too shallow and should be between 2 and 3 degrees from the factory. If you can dial in more than 3 that'd be great Too shallow will cause wander other issues that will affect the stability feel of a vehicle.. I'd like to see your camber under 1 degree negative. I understand you frustration. If you'd like, post pics of your shim packs and I'll see if I can help get you straight.

[eightbanger]

Originally Posted by BMERDOC

First thing's first....swap the front tires side-to-side. I understand you frustration. If you'd like, post pics of your shim packs and I'll see if I can help get you straight.

Yes please mate, i'm desperate for this kinda help. I'll get some pics taken and post em up.

Thank you.

[eightbanger]

Nick, I took the wheels off and switched them round as you suggested and to my complete surprise the truck now pulls to the left...how is that possible? is there a right and left wheel because its as different as putting my shoes on the wrong feet

Does it need to be aligned again? surely not!

[BMERDOC]

Your truck has a condition know as Tire Pull. The old alignment is now "burned" into the tread causing the condition. Swapping tires side to side proved this. The truck now wants to go left. If your tires are the same all the way around you do have the option of swapping one of the tires to the diagonal corners to see if the pull goes away (left front to right rear or vice versa). The only other option if you were serious about eliminating the pull is to purchase a new pair for the front. Aligning it again would not show any improvements. If you decide to mess with the shim packs to correct caster and camber you'll want to have the alignment rechecked.

[eightbanger]

Thank you mate, I really do appreciate your help and advice, I will swap the wheels and let you know what happens, and I really want to get a handle on this whole caster/camber thing, so i'll take some pics of the shim packs tomorrow.

Thanks

[eightbanger]

Well Nick here's the scooby, switched all the wheels diagonally as suggested, and when I took her out she drove nice and straight...Thank you man. I can't tell ya how over the moon I'am to have this finally sorted....BUT! when I took the front wheels off (one of which had been causing it to pull to the Right, then when switched it pulled to the Left) well I know why, one of the tires had a large bulge running about half way round the tire.

I took some pics of the shim packs for you also. First two are of the PS, the last iS DS.

[jjzepplin]

That will certainly do it. I think you may also be missing some big rounded type spacers behind those control arm bolts.

[Hart_Rod]

Just had my 86 C10 aligned. It's got a flip kit in rear which equated to about 8" of drop and a 3" spindle with 3" dropped springs in the front. Here's the alignment paperwork. Thoughts?

[Advanced Design]

Hart_Rod, are the caster and camber in the positive range? If so, does your truck pull left?

[tinydb84]

I remember reading in the make it handle thread that you should avoid postive camber. Do you still have any shims in the upper control arms?

[BMERDOC]

Sorry Guys. I'm usually quicker with responses. Looks like I dropped the ball. Here we go...

Eightbanger: That tire has a busted belt and should be replaced before it completely fails. The alignment shop should have spotted this before the alignment. It can affect the anlges of your alignment. I feel like they owe you a freeby alignment once you get a good tire on it. JJZepplin was right. It looks like you may be missing some spacers. The top and middle picture shows them behind the shim packs on the right side but its hard to tell if the others have them. You have excessive negative camber (I like to see no more than -1 degree. You don't have enough positive camber. Both the missing spacers and the bad tire can affect this and the readings. Can you confirm all the spacers are intact? BTW, I see an E46 in your driveway. What model is it? They don't call me BMERDOC for no reason.


Hart Rod: This is a great example of how green is not always good. Your camber started out in the negative range, which is good but then they added shims to move it into the positive range. While it is in spec, positive camber is not good. They also show your caster as non-adjustable but we both know it is. The difference in side to side caster is over 1 degree. Because the ride side is higher it would cause your truck to drift or pull to the passenger side. I wouldn't want to see more than .25 degrees difference from side to side. The shop you used has a Hunter machine. In my signature you will find a link called "Easiest Alignment Ever". If you show them this link they can align your truck like I did mine and its the fastest route to get a great alignment for your truck.

[eightbanger]

Originally Posted by BMERDOC

Sorry Guys. I'm usually quicker with responses. Looks like I dropped the ball. Here we go...

Eightbanger: That tire has a busted belt and should be replaced before it completely fails. The alignment shop should have spotted this before the alignment. It can affect the anlges of your alignment. I feel like they owe you a freeby alignment once you get a good tire on it. JJZepplin was right. It looks like you may be missing some spacers. The top and middle picture shows them behind the shim packs on the right side but its hard to tell if the others have them. You have excessive negative camber (I like to see no more than -1 degree. You don't have enough positive camber. Both the missing spacers and the bad tire can affect this and the readings. Can you confirm all the spacers are intact? BTW, I see an E46 in your driveway. What model is it? They don't call me BMERDOC for no reason.

Your a diamond mate, and no appologies nessasary, just glad to have this help from a pro, it's invaluable, at last I have a chance of getting the alignment done right and educated on the way.
The sun was splitting the trees yesterday, but the British weather being what it is it's cold and pissing down today, so no chance to get out and confirm if those spacers are there or not...i'll get back to you on that. Yes my old 1999 323 on the drive, I always say if you want a reliable well built run around as your other car...buy German.

[eightbanger]

Originally Posted by BMERDOC

Can you confirm all the spacers are intact?

Yes it looks like they are definately in there Nick.
Can you tell me whether it's positive or negative caster that I need to get the steering to return by itself? also im confussed about shims.....if I want more positive caster do I add or subtract shims from the front or back and vice versa for negative?

Thanks

[BMERDOC]

Yup, they are there. You'll want Positive caster (upper ball joint is tilted rearward on the axis in relation to the lower joint). You can add shims to the front or remove them from the rear to increase Postive caster. The prefered methos is what we refer to as the "Caster Mod". It will greatly increase positive caster and in something you can do in you fore court. The shims can still be used for fine adjustments. From what I remember you had little to no caster initally and excessive camber on the left side. If you can get camber somewhere between -.5° and _1.3°, caster as high as 6° to 7° and 1/16 toe per side and as equal as possible you are gonna have one nice driving truck. Good Luck and Cheers! Keep the questions coming when needed and keep us in the loop!

[eightbanger]

Originally Posted by BMERDOC

Yup, they are there. You'll want Positive caster (upper ball joint is tilted rearward on the axis in relation to the lower joint). You can add shims to the front or remove them from the rear to increase Postive caster. The prefered methos is what we refer to as the "Caster Mod". It will greatly increase positive caster and in something you can do in you fore court. The shims can still be used for fine adjustments. From what I remember you had little to no caster initally and excessive camber on the left side. If you can get camber somewhere between -.5° and _1.3°, caster as high as 6° to 7° and 1/16 toe per side and as equal as possible you are gonna have one nice driving truck. Good Luck and Cheers! Keep the questions coming when needed and keep us in the loop!

Thank you very much for your help Nick, it is greatly appreciated
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[eightbanger]

Hi Nick, I have taken a couple of new pics after removing more shims in an effort to get the camber to -.5, you'll notice that on the PS I am unable to get the same reading as the DS, I had to remove all but 1 shim and in an effort to get it near -.5 and to get any pos caster on the PS I now have no shims....this can't be correct, is it?

[BMERDOC]

Yup, thats pretty much correct! If you look in my Sig you'll see a link called Easiest Alignment Ever. Look at that post. My passenger side had no shims whatsoever and my driver's only required a total of three shims.

[eightbanger]

Thank you Nick for all your help, we're very lucky to have you here...

[picklito]

After a little home tweaking, I'm pretty close to "neutral" on all my specs now. Caster is about 2 degrees, and I have equal shim thickness at front and back locations on the upper control arm...

How much shim differential can I run between the front and back locations? Can I add a bunch to the front and remove from the rear to increase caster? I know the answer is "yes," but how much of an angle can I put into that cross shaft?