Went for an alignment- positive camber& no shims

[ryangreen19]

I recently finished re-building the entire front end of my 68 c10, I swapped spindles out of an 85 to get discs, but kept the 68 control arms. I also did the Caster mod, I wan't as aggressive as some but moved things forward a 1/2". The issue I appear to be having now is that I have positive camber on both sides and no shims in yet to increase caster. Caster is in the 1-2 range and needs to go up obviously. The alignment sheet showed about +0.3 camber give or take on both sides before any shims to increase caster. Now from searching these forums, this doesn't make a lot of sense. I get the sense that camber should be slightly negative without any shims. The caster mod would have no effect. The spindles wouldn't either. What came to mind tonight was the springs. I have the HD spring option in the front and rear, but I boobed and ordered standard spring for the front. The free height of what I have, GM 45H0011 is 13.18", installation height 10.00". The HD (45H0041) springs free height is 12.56" and installation height is 10.00". Could this 0.62" make the difference? I know from reading that short springs give you too much positive camber, too tall would do the opposite right?

Thanks in advance.

[SCOTI]

Originally Posted by ryangreen19

I recently finished re-building the entire front end of my 68 c10, I swapped spindles out of an 85 to get discs, but kept the 68 control arms. I also did the Caster mod, I wan't as aggressive as some but moved things forward a 1/2". The issue I appear to be having now is that I have positive camber on both sides and no shims in yet to increase caster. Caster is in the 1-2 range and needs to go up obviously. The alignment sheet showed about +0.3 camber give or take on both sides before any shims to increase caster. Now from searching these forums, this doesn't make a lot of sense. I get the sense that camber should be slightly negative without any shims. The caster mod would have no effect. The spindles wouldn't either. What came to mind tonight was the springs. I have the HD spring option in the front and rear, but I boobed and ordered standard spring for the front. The free height of what I have, GM 45H0011 is 13.18", installation height 10.00". The HD (45H0041) springs free height is 12.56" and installation height is 10.00". Could this 0.62" make the difference? I know from reading that short springs give you too much positive camber, too tall would do the opposite right?

Thanks in advance.

You're on the right track. A shorter spring would/should yield neg camber ~ zero. A taller spring would/should yield zero ~ pos camber.

[ryangreen19]

I would imagine that it would be easiest to simply cut a small length off the coil to get things in order. I don't want to lower my ride height any more than necessary. Would a cutoff wheel on a grinder heat things up to much? Or should I try and find a hacksaw blade up to the job.

[oldman3]

Cut off wheel will work fine. But before you cut the spring, have you driven the truck for at least 100 miles. Sometimes it takes that long for them to settle to their ride height. I've cut springs before driving and after they were to short, live and learn...Jim

[chevyguyase]

I like the .03 positive camber. Are you more than .5 degree apart on your caster left and right? For instance +1.5 and +1.1. If you are within .5 degrees I'd set the toe in and road test it. If you need more caster your steering wheel will not return to center. If it goes straight down the road and doesn't wander and the steering wheel returns to center I'd drive it. Radial tires like a lot of caster but a road test is where I would start.

[ryangreen19]

I am 3.2 DS and 1.3 PS for caster. There is a definite difference steering. Easy to go right, bit harder to turn left. I think I am going to have to reduce spring length to get enough negative camber in order to match my caster better. I did a quick toe-in alignment with tapes on my treads and it sure drives straight for the time being.

[BCash]

Reviving an older thread since I have a similar issue:

My 1968 c20 got a full front suspension/brake overhaul and I ended up swapping in half ton parts off of a 73+ squarebody truck to achieve disc brakes. I used the squarebody lower control arms/spindles/steering arms/brake parts but kept the 68 c20 uppers and put in new ball joints.
Everything went together perfectly although I didn't realize until about a year later that there is a lot of positive camber and there are no shims on the upper control arm cross shafts that I can remove to dial the camber back into spec. Are the 68 c20 upper control arms longer than 73 and later c10 ones? I see now that I should've swapped the full crossmember but it's too late for that.
Is my only option now to try and get some 73+ upper control arms? I'm also at stock ride height, so no issues from drop springs or spindles etc. If anyone has any recommendations, I'm all ears. Thanks!

[SCOTI]

Originally Posted by BCash

Reviving an older thread since I have a similar issue:

My 1968 c20 got a full front suspension/brake overhaul and I ended up swapping in half ton parts off of a 73+ squarebody truck to achieve disc brakes. I used the squarebody lower control arms/spindles/steering arms/brake parts but kept the 68 c20 uppers and put in new ball joints.
Everything went together perfectly although I didn't realize until about a year later that there is a lot of positive camber and there are no shims on the upper control arm cross shafts that I can remove to dial the camber back into spec. Are the 68 c20 upper control arms longer than 73 and later c10 ones? I see now that I should've swapped the full crossmember but it's too late for that.
Is my only option now to try and get some 73+ upper control arms? I'm also at stock ride height, so no issues from drop springs or spindles etc. If anyone has any recommendations, I'm all ears. Thanks!

Swapping the entire x-member is an option, not a 'need'.
The upper arms are roughly the same length as are the lowers.

[BCash]

Thanks for the reply. I guess I'm trying to figure out what the issue is that's causing excessive positive camber; maybe the squarebody lower arms are shorter or it's something to do with the spindle?
I know I could take the upper arm cross bars off and grind down the spacer/back of the cross arm, but that will leave no room for any alignment adjustments at all. Just looking for some advice on what to do - I still need to get a good pic of the positive camber but it's obvious just from eyeballing it on the ground.

[SCOTI]

Originally Posted by BCash

Thanks for the reply. I guess I'm trying to figure out what the issue is that's causing excessive positive camber; maybe the squarebody lower arms are shorter or it's something to do with the spindle?
I know I could take the upper arm cross bars off and grind down the spacer/back of the cross arm, but that will leave no room for any alignment adjustments at all. Just looking for some advice on what to do - I still need to get a good pic of the positive camber but it's obvious just from eyeballing it on the ground.

As mentioned, the arms are basically the same (both upper & lowers). The bushings were different & the BJ sizes vary depending on size/weight of the chassis (1/2 ton vs 3/4 & 1-ton).
I have OE stamped steel 63-72 1/2 ton upper arms (w/1-ton BJs) on my CC Squarebody dually. It had the stock lowers & now has Porterbuilt 1" Forward aftermarket lowers.

Hopefully you can that pic & post it so we can get a better idea of what you're up against.

[BCash]

https://imgur.com/a/qKfJkfh

Here's a quick gallery of some photos, you can sort of see the positive camber when it's sitting on the ground.

[HO455]

What are your alignment specs?

[BCash]

Originally Posted by HO455

What are your alignment specs?

Haven't been to an alignment shop yet since I already know they'll tell me it is out of spec for camber and there isn't any adjustment left. Here are a few better photos (forgot how to properly attach these in previous posts). You can see it has positive camber with the naked eye which means it's gotta be out by at least a few degrees. You can also see that there aren't any shims on the UCAs

[HO455]

Are the control arms on the correct sides? From the photos I can't tell if the upper control arms are. It is easy to get them backwards. The rubber bump stop should towards the rear of the truck.

Do you have the correct concave washers between the shaft and the frame? See photo.

[BCash]

Yes sir, control arms are on the correct side with bump stops to the rear and concave washers are in place behind the UCA cross bars. Mine are square shaped/flat on the top so they're a little tricky to see in that photo

[SCOTI]

I'm curious if there is a variance on the dimensions of the shaft itself?

[BCash]

Originally Posted by SCOTI

I'm curious if there is a variance on the dimensions of the shaft itself?

That would be interesting. I measured from the shaft to the center point of the ball joint and it's almost exactly 9" which seems to be the norm.
I re-used the 1968 upper control arms and bought new cross shafts and ball joints when I did this disc brake swap, so there was no real change there from the factory drum setup. I'm thinking there's something different in either the lower control arm whether it be length or some other metric, or possibly the spindle dimensions from the late 70's donor truck front clip I used that is causing this camber issue.

[pjmoreland]

Here's an option.

https://www.performanceonline.com/19...-Control-Arms/

The stock convex washers are not easy to remove.

[ryangreen19]

I still haven't figured this out on mine. That being said I have not had any time until now. I am going to check out the camber now that my springs have had 7 years to sag a bit....

[BCash]

Originally Posted by ryangreen19

I still haven't figured this out on mine. That being said I have not had any time until now. I am going to check out the camber now that my springs have had 7 years to sag a bit....

Similar situation here, I've been scratching my head thinking of a good solution but haven't quite come up with a good one yet. Those smaller concave washers would help but probably wouldn't completely solve the problem.

I'm thinking the disc brake spindle is taller than the drum one which is causing the excessive positive camber. It's either that or the disc brake crossmember itself has the lower control arms mounted slightly further out. Those are the only two options I can see causing the geometry issue for our swaps. Unfortunately I scrapped the disc brake crossmember I got when I made the swap, mostly because I didn't want to go through the hassle of using it and assumed they were the same.

Anyways, update this thread if you figure out a good solution/answer to the riddle!

[SCOTI]

Originally Posted by BCash

Similar situation here, I've been scratching my head thinking of a good solution but haven't quite come up with a good one yet. Those smaller concave washers would help but probably wouldn't completely solve the problem.

I'm thinking the disc brake spindle is taller than the drum one which is causing the excessive positive camber. It's either that or the disc brake crossmember itself has the lower control arms mounted slightly further out. Those are the only two options I can see causing the geometry issue for our swaps. Unfortunately I scrapped the disc brake crossmember I got when I made the swap, mostly because I didn't want to go through the hassle of using it and assumed they were the same.

Anyways, update this thread if you figure out a good solution/answer to the riddle!

I have never seen ANY differences (dimensionally) discussed regarding a-arm locations for the x-members. Drum vs disc x-members had different brake line mounting tabs/locations but bolt-in & locate the arms in the same place.

As far as any info I've ever come across, there is also no dimensional difference on the height of the disc brake spindle vs the drum spindle. I did my first aftermarket spindle swap back around 1988 under a 67/67 pick-up & have done more than a few since.

My bet is if there's a dimensional difference, it's @ the upper a-arm cross-shaft & the requisite spacers specific to that style of shaft. Things changed along the years so I can see the possibility of variance there.