6066 (1960-1966) GMC Truck Club Bitcoin now accepted here! 
Pay Dues
Pay Dues or become a Site Supporter
 



Go Back   6066 (1960-1966) GMC Truck Club > 6066 GMC Truck Club Forum > Wheels, Tires, Suspension and Brakes


Wheels, Tires, Suspension and Brakes Keep them doggies rollin', rawhide

Reply
 
Thread Tools
  #1  
Old March 6th, 2021, 02:53 AM
biscaynebirdie biscaynebirdie is offline
Junior Member
 
Join Date: Jan 2021
Location: Santa Rosa, California
Truck: 1965 1000 Series with 250 engine and SM420 transmission
Posts: 26
Rep Power: 27
biscaynebirdie is on a distinguished road
Default Positive camber... just remove the shims?

It seems that after installing disc brakes on the front of my 1965 1000, I have some positive camber. After only about 10,000 miles, I have destroyed the outside of my 255/60R15 BF Goodrich Radial TAs.

I’m bringing the truck into Les Schwab on Monday for new tires (255/70R15 Cooper Cobra Radial GTs), and am curious if they will be able to fix the positive camber without needing any new parts. Will it be as simple as removing the original shims? I’m going to replace the tie rods tomorrow morning (might as well do it now... most of the boots are cracked/missing).

Thoughts?
Reply With Quote
  #2  
Old March 6th, 2021, 05:31 AM
FetchMeAPepsi's Avatar
FetchMeAPepsi FetchMeAPepsi is offline
-= Dues Paid =-
 
Join Date: Jan 2013
Location: Edmond, Ks
Truck: 1962 4x4 GMC CECILIA
Posts: 1,724
Rep Power: 545
FetchMeAPepsi is a glorious beacon of lightFetchMeAPepsi is a glorious beacon of lightFetchMeAPepsi is a glorious beacon of lightFetchMeAPepsi is a glorious beacon of lightFetchMeAPepsi is a glorious beacon of light
Default Re: Positive camber... just remove the shims?

Depends on where the shims are and what you did to set it up. Got any pics? Details?
__________________
Step by steps:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Some people are like slinkys. Not worth much but funny as heck when pushed down stairs.
__________________
If the women don't find you handsome, they should at least find you handy.
Reply With Quote
  #3  
Old March 6th, 2021, 07:21 AM
biscaynebirdie biscaynebirdie is offline
Junior Member
 
Join Date: Jan 2021
Location: Santa Rosa, California
Truck: 1965 1000 Series with 250 engine and SM420 transmission
Posts: 26
Rep Power: 27
biscaynebirdie is on a distinguished road
Default Re: Positive camber... just remove the shims?

The only things we changed on the front end was the new spindles for the disc brakes and the rims. We replaced the upper and lower ball joints for safety's sake. Nothing else has been messed with other than replacing the shock absorbers. Control arms, shim placement, steering box, and coil springs are all original. The first photo is the driver side (you can clearly see the steering shaft) and the second is the passenger side.
Attached Images
File Type: jpg IMG_3392.jpg (1.98 MB, Multiple views, 9 clicks)
File Type: jpg IMG_3395.jpg (1.86 MB, Multiple views, 9 clicks)
Reply With Quote
  #4  
Old March 6th, 2021, 08:25 PM
James James is offline
-= Extreme Supporter =-
 
Join Date: Jun 2013
Location: Greer, SC
Truck: 1964 GMC 1500 2wd
Age: 69
Posts: 432
Rep Power: 199
James will become famous soon enoughJames will become famous soon enoughJames will become famous soon enough
Default Re: Positive camber... just remove the shims?

Changing the spindle is enough to require a front end alignment. Worn parts: the old spindle might had a slight bend in them from years of driving, worn ball joints, or toe in too much. Plus manufacture tolerance can play a role in it. In my opinion any time I do front end work I perform a alignment check. Money ahead in my book. Whoever perform the alignment will be changing/adjusting the shims to get the caster and camber correct. And with our trucks the frame angle is taken into account (ref. the manual).

One thing to note if you have manual steering. Make sure your caster is close to zero on the positive side. This will make steering easier when drive slowly.
Reply With Quote
  #5  
Old March 7th, 2021, 05:13 PM
Sonic65's Avatar
Sonic65 Sonic65 is offline
Senior Member
 
Join Date: Sep 2013
Location: San Antonio Texas
Truck: 1965
Posts: 100
Rep Power: 95
Sonic65 is on a distinguished road
Default Re: Positive camber... just remove the shims?

Quote:
Originally Posted by biscaynebirdie View Post
The only things we changed on the front end was the new spindles for the disc brakes and the rims. We replaced the upper and lower ball joints for safety's sake. Nothing else has been messed with other than replacing the shock absorbers. Control arms, shim placement, steering box, and coil springs are all original. The first photo is the driver side (you can clearly see the steering shaft) and the second is the passenger side.
The offser of the new rims could be enough to add stress to the existing parts and cause wear on the tires.
Reply With Quote
  #6  
Old March 7th, 2021, 08:22 PM
James James is offline
-= Extreme Supporter =-
 
Join Date: Jun 2013
Location: Greer, SC
Truck: 1964 GMC 1500 2wd
Age: 69
Posts: 432
Rep Power: 199
James will become famous soon enoughJames will become famous soon enoughJames will become famous soon enough
Default Re: Positive camber... just remove the shims?

Take a tape measure and measure the toe on the front and back of the front tires. Should be toe in approx 1/8" (front of tire closer together than the back of the tire), this allow the wheels to roll down the road straight. Too much toe in could cause excessive wear on the outside edge of the tires. Too much toe out can cause excessive wear on the inside edge of the tires. Also wider rim/tire will make this wear more noticeable.
Reply With Quote
  #7  
Old March 10th, 2021, 06:01 PM
biscaynebirdie biscaynebirdie is offline
Junior Member
 
Join Date: Jan 2021
Location: Santa Rosa, California
Truck: 1965 1000 Series with 250 engine and SM420 transmission
Posts: 26
Rep Power: 27
biscaynebirdie is on a distinguished road
Default Re: Positive camber... just remove the shims?

Well, got the truck back from the shop. I could instantly feel the difference in ride, as well as ease of turning. It feels like it rolls much more smoothly. They removed most of the original shims as well as added some new ones.

Unfortunately someone made a mistake and accidentally ordered two 225/70R15s for the front instead of 255/70R15s all around, so I'll be bringing it back into the shop on Friday to swap them out. I didn't even realize it until I was looking at the truck from a distance, noticed something looked off, and checked the numbers. I know a lot of people like the staggered look, but I'm not the biggest fan.

My biggest concern is this... If they did the alignment with these smaller tires up front, should they recheck the alignment once they put the 255s up front or does it not matter?

Here's the before and after alignment adjustments, as well as a photo of how it looks (for now):
Attached Images
File Type: jpg 63693341099__3873A8C6-3A5B-4F16-A813-7B69CFC28EDA.jpg (1.05 MB, Multiple views, 10 clicks)
File Type: jpg IMG_3473.jpg (1.35 MB, Multiple views, 9 clicks)
Reply With Quote
  #8  
Old March 10th, 2021, 10:32 PM
James James is offline
-= Extreme Supporter =-
 
Join Date: Jun 2013
Location: Greer, SC
Truck: 1964 GMC 1500 2wd
Age: 69
Posts: 432
Rep Power: 199
James will become famous soon enoughJames will become famous soon enoughJames will become famous soon enough
Default Re: Positive camber... just remove the shims?

Yes it will affect the alignment. It will increase the Caster, making it harder to steer with manual steering (power steering not so much). With that much camber and over an inch of toe-in no wonder your tires got ate up.

In fact with that much caster with manual steering it would still be hard to turn the wheel. In my 64 maintenance manual it stated I needed to set it to approx .5° and I have manual steering. Before I adjusted it it had over 3° and extremely hard to steer.
Reply With Quote
  #9  
Old March 10th, 2021, 11:01 PM
biscaynebirdie biscaynebirdie is offline
Junior Member
 
Join Date: Jan 2021
Location: Santa Rosa, California
Truck: 1965 1000 Series with 250 engine and SM420 transmission
Posts: 26
Rep Power: 27
biscaynebirdie is on a distinguished road
Default Re: Positive camber... just remove the shims?

Quote:
Originally Posted by James View Post
Yes it will affect the alignment. It will increase the Caster, making it harder to steer with manual steering (power steering not so much). With that much camber and over an inch of toe-in no wonder your tires got ate up.

In fact with that much caster with manual steering it would still be hard to turn the wheel. In my 64 maintenance manual it stated I needed to set it to approx .5° and I have manual steering. Before I adjusted it it had over 3° and extremely hard to steer.
Well shoot... Should I say something to the tech about it Friday morning? I can't really afford to pay another $90 for alignment at the moment.

The 1964 GMC manual calls for .5° caster? The 1963 Chevrolet Truck Shop Manual (if I am reading the chart correctly) calls for 2° caster at 0° camber, so it seems like the tech got pretty close to spec. I have a scan of the chart on my computer, but I'm not sure if I should share it here for copyright infringement reasons.
Reply With Quote
  #10  
Old March 11th, 2021, 01:26 AM
James James is offline
-= Extreme Supporter =-
 
Join Date: Jun 2013
Location: Greer, SC
Truck: 1964 GMC 1500 2wd
Age: 69
Posts: 432
Rep Power: 199
James will become famous soon enoughJames will become famous soon enoughJames will become famous soon enough
Default Re: Positive camber... just remove the shims?

Quote:
Originally Posted by biscaynebirdie View Post
I have a scan of the chart on my computer, but I'm not sure if I should share it here for copyright infringement reasons.
I don't know the copyright laws, but I been lead to believe if it been over 20 years since the last copyright date in the document then it can freely be copy. Maybe someone else that know more can chime in for clarification.

My caster is what is measured at the wheel without taking into account the ride height or frame angle. Your manual should show you a formula on getting the corrected caster angle. My frame angle is 2.5°. So my corrected caster is 3°. Also the manual talk about ride height of the front suspension, this give me the range for my caster setting. Both measurements is used to determine corrected caster for different load on the truck. Even my 79 Chevy pickup 1/2 ton maintenance manual make reference to frame angle for setting the caster.

Hope this help.
Reply With Quote
Reply

Bookmarks

Tags
camber, camber adjustment, disc brake, positive camber

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
starter shims Texas63GMC GMC V6 and V12 Engines 5 September 27th, 2015 07:20 AM
Alternators and "shims" Archiver Previous Forum Posts 0 January 5th, 2004 12:56 AM
3 speed shims Archiver Previous Forum Posts 0 January 4th, 2004 04:58 AM
3 speed shims Archiver Previous Forum Posts 0 November 11th, 2003 12:20 AM
...on a positive note.... Archiver Previous Forum Posts 0 December 11th, 2002 09:26 AM


All times are GMT +1. The time now is 08:56 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, Jelsoft Enterprises Ltd 681711554703|1710402985|0