After a complete front end urethane kit was installed on my 66 427 the front end shop complained that I STILL need more shims.
He is using a high tech laser alignment system and ensured me it is extremely accurate.
It used to have minimum shims and the Vette went down the road dead straight w/o pulling before the new front end was installed.
He also complained that the right rear suspension needed additional shims.
He suggested installing offset upper control arms shafts.
http://www.ecklers.com/product.asp?p...8&dept_id=1790
Do I need two or just on the side that needs the extra shims?
I doubled check and made sure I did not have the upper control are reversed.
Can anyone provide any time saving and safety hints to make this job easier?
Does the spring have to be removed again?
What a Disappointment / nightmare!
Thanks in advance for helping!
Andy

 

You may have found that your frame is out of wack, and the accuracy established by all new stuff is exposing it. How experienced is the system operator? The shop owner could be shopping in your wallet. Dennis

 

Andy:

I have the VBP offset upper control arms on my car.

My alignment guy uses a Hunter machine that is the laser type also. He was able to obtain factory correct settings with the stock uppers but I didn't want stock settings. They could not be achieved with the stock uppers but by changing to the offset uppers we were able to make it.

You don't have to remove the spring to change the upper arm out.

I don't know if they sell the offset arms individually but you would want to replace as a pair anyway. They are visually quite different from your stock arms.

Rich

 

My alignment guy is also using the Hunter laser based alignment system and has over 20 years of experienced.
What does the installation of the offset upper control job involve?
1. Remove both front wheels – can the calipers remain on?
2. Does the shock have to be removed?
3. Jack the lower control arm & remove the upper (should a chain be used to make this is safer operation? I’m concerned that the car will lift up and not compress the new stock BB spring.
4. Is the removal and installation of the offset arms a big deal with the urethane bushing?
5. Can the urethane bushing be used again or will new ones have to be installed? The kit comes with rubber bushing but I would like to stick with the urethane.
Any information to make this job easier will be much appreciated!
Thanks again!
Andy

 

You said he is recommending offset control arms shafts, not offset control arms. The offset shafts are for camber adjustment and the offset arms are for increased caster adjustment. What are the alignment specs he achieved?

 

Good Read Tom:

The offset shafts should be available from your FLAPS.

Rich

 

those offset shafts are from MOOG, you can buy them cheaper from rock auto dot com....

 

Stock shaft on the left, offset shaft on the right.

 

I assume these offset control arm shafts allow more caster

I could use a bit more

Where can I get a set ??

 

They provide more camber.

Jim

 

Hello Sky65,

Here are the alignment specs for my 1966 Big Block.
Primary Angles



Front Caster Left Init -0.20 Spec 1.25 - 3.25 Final 0.52
Caster Right Init 2.41 Spec 1.25 - 3.25 Final 2.59

Camber Left Init 0.16 Spec 0.25 - 1.25 Final 0.62
Camber Right Init 0.03 Spec 0.25 - 1.25 Final 0.21

Toe Left Init -0.11 Spec 0.09 -0.15 Final 0.12
Toe Right Init -0.29 Spec 0.09 - 0.15 Final 0.11
Total Init -0.41 Spec 0.19 -0.31 Final 0.23

Rear Camber Left Init -3.04 Spec -0.05 - 0.5 Final 0.14
Camber Right Init -0.55 Spec -0.05 - 0.5 Final 0.07

Toe Left Init -0.17 Spec 0 - 0.06 Final 0.03
Toe right Init -0.19 Spec 0 - 0.06 Final 0.23
Total Init 0.02 Spec 0 -0.12 Final 0.26
Thrust Angle Init -0.37 Final -0.2


I just received the offset shafts and want to make sure I install them correctly. Does the offset go towards the engine? Another words - I want to move the upper control arm towards the engine!

Thanks to everyone for your help!
Andy

 

I would suggest using the specs John Z recommends and see if that allows the alignment to come in without the offset parts. Nothing wrong with the offset parts but maybe you won't need them. Assuming stock suspension and radial tires.

http://forums.corvetteforum.com/c1-a...ent-specs.html

 

I purchased and installed the moog offset shaft on the right hand upper control arm.
However, as sanity check, I want to make sure the upper right control arm in on the right side of the Vette.
How can I definitively determine the difference between the upper left & upper right control?

Thanks!
Andy

 

The upper control arms are decidedly different RH and LH parts; if you had them reversed, the upper ball joints would be WAY forward, and you'd never be able to get positive caster readings. Photo below shows the difference in angle/contour between the front and rear surfaces.

 

You might want to call Paul at VB&P...he's very knowledgeable about these suspensions and may be able to help you figure this out.

 

After a complete front end urethane kit was installed on my 66 427 the front end shop complained that I need more shims.

He is using a Hunter Engineering, laser alignment system, and ensured me it is extremely accurate.

It used to have minimum shims and the Vette went down the road dead straight w/o pulling before the new front end was installed.

He also complained that the right rear suspension needed additional shims. This was serviced by a mechanic many years ago & he may have copied the shim placemtn form the other side & now it is creating problems.

He suggested installing offset upper control arms shafts.
http://www.ecklers.com/product.asp?p...8&dept_id=1790

I recently installed Moog offset control arms which after an alignment should take care of this issue.

I’m currently working on removing the rear trailing arm bolts & plan to install new bolts, nuts & slotted shims.
Here are my questions:
1. Can anyone provide any time saving and safety hints to make this job easier?

2. Reviewing the spec below can anyone tell me how many shims I have to add or subtract to get the RR trailing arm in spec?
The alignment shop will not work on the car unless I replace the bolts & shims.
I want to get it as close as possible so he does not have to adjust the Rear Toe.

Primary Angles



Front Caster Left Init -0.20 Spec 1.25 - 3.25 Final 0.52
Caster Right Init 2.41 Spec 1.25 - 3.25 Final 2.59

Camber Left Init 0.16 Spec 0.25 - 1.25 Final 0.62
Camber Right Init 0.03 Spec 0.25 - 1.25 Final 0.21

Toe Left Init -0.11 Spec 0.09 -0.15 Final 0.12
Toe Right Init -0.29 Spec 0.09 - 0.15 Final 0.11
Total Init -0.41 Spec 0.19 -0.31 Final 0.23

Rear Camber Left Init -3.04 Spec -0.05 - 0.5 Final 0.14
Rear Camber Right Init -0.55 Spec -0.05 - 0.5 Final 0.07

Toe Left Init -0.17 Spec 0 - 0.06 Final 0.03
Toe right Init -0.19 Spec 0 - 0.06 Final 0.23
Total Init 0.02 Spec 0 -0.12 Final 0.26
Thrust Angle Init -0.37 Final -0.2

Thanks!
Andy

 

There is a link to rear wheel alignment in the help section at the bottom of my home page (http://home.mchsi.com/~magicv8) that has the info on calculating rear shim thickness changes.

To get increased caster (3.5) in my 66, I replaced the factory bolts with longer (grade8) bolts that allowed a spacer to be placed at the base of the shims. Nothing else had to be removed.

 

You are all talking about caster. Is the problem that you have to much positive camber and want more negative camber?

 

Correction...Paul at Van Steel

 

Here are the questions:
1. What is the thickness of the Right Rear shim that has to be added or subtracted from the inner or outside trailing arm to meet GM spec?

2. I only want to remove & replace the trail arm bolts to get the rear suspension w/ in spec.
At this time I do not plan to remove the entire trailing arm unless I have to.
Is it safe to remove the training arm bolt w/ 4 jack stands supporting the frame & nothing supporting the trailing arm?
I'm very concerned about the rear spring pressure & getting a new bolt back in place w/ the rest of the trailing arm still attached.
Thanks!
Andy