Positive camber on rear wheels after installing spring relo kit and SS springs

-
rkh17

rkh17

Active Member
Joined
Aug 25, 2014
Messages
28
Reaction score
3
Location
Maryland
Looks like my wheels are showing a bit of positive camber after the following work on my rear end:

1) Mopar spring relocation kit installaiton (used for more clearance with larger tires)
2) New SS springs (P3412002/3)
3) new 15x8 wheels (moved from 15x6.5's)
4) new 275 60 R15 tires. (upgraded from 235's)

Car is a 1972 Plymouth Duster which I primarily use only for bracket racing. It is on the street but doesn't go there much except for a test drive or cruise-in that is w/in 5 miles.

Questions:

1) So positive camber looks bad. Is it an issue? How to best address the condition.

2) I'm in the lower hole on the front bracket of the spring relocation kit. Differences between upper and lower holes (obviously ride height) with respect to racing?

Thanks,
-Rob

photo 1.JPG


photo 2.JPG


photo 3.JPG


photo 4.JPG
 
Last edited:
It doesn't say you changed shocks which is required with the ss springs , hard to tell by the photos but the passenger side should be higher than the drivers and at rest the passenger side wheel should be 1/2 inch forward of the drivers side , it's referred to as thrust angle in the books and the increased arc of tge passenger spring causes it . under launch load the spring compresses farther and the wheel mives back into line creating a straight launch.
 
cannucky said:
It doesn't say you changed shocks which is required with the ss springs , hard to tell by the photos but the passenger side should be higher than the drivers and at rest the passenger side wheel should be 1/2 inch forward of the drivers side , it's referred to as thrust angle in the books and the increased arc of tge passenger spring causes it . under launch load the spring compresses farther and the wheel mives back into line creating a straight launch.
Click to expand...

Hey Cannucky, Thanks for the response.

I have not changed the shocks. What is recommend. Seems I missed that part.

As for the height, I took measurements before and after and my right side (passenger side) is now measured higher. There is a difference in the front clearance as well between left and right sides. I will need to check my book tonight and can quote back.
 
You need to explain what you are seeing better. The only way to cause toe in on a solid axle is if you bent the housing, which I doubt.
If 1 side in pointing inward (at the front of the tire) the other side should be pointing outward. As already stated this is called thrust angle not toe.
Measure wheel base on both sides of the car and compare it.
 
Lonewolf3165 said:
You need to explain what you are seeing better. The only way to cause toe in on a solid axle is if you bent the housing, which I doubt.
If 1 side in pointing inward (at the front of the tire) the other side should be pointing outward. As already stated this is called thrust angle not toe.
Measure wheel base on both sides of the car and compare it.
Click to expand...

Hey LoneWolf,

Thanks for your reply. It may just be an optical illusion so I will have to try to do some more measuring this evening. What I'm seeing with my eyes is that tops of each wheel are leaning out from the centerline (positive camber).

Any thoughts on the choice of hole in the front brackets? Somebody said it looks like the rear is sitting pretty high.

Thanks,
-Rob
 
Last edited:
Okay we're not talking about the front wheels right? What you're describing is called CAMBER, and again it's not affected by anything but the rear axle housing. It may be an illusion caused by the body sitting higher on the one side of the car. Take some measurements and let us know what you find.
 
Some have used C body shocks but I got the proper # number from the Mopar Performance Catalogue and oredered a pair through the local dealers parts dept , they were cheaper than the KYB's they replaced , basically you need a longer shock to accomodate the taller springs .
 
Lonewolf3165 said:
Okay we're not talking about the front wheels right? What you're describing is called CAMBER, and again it's not affected by anything but the rear axle housing. It may be an illusion caused by the body sitting higher on the one side of the car. Take some measurements and let us know what you find.
Click to expand...

FYI - I'm talking about just the rear wheels... and yes sorry I meant Camber. Seeing positive camber. Corrected the title accordingly.

-R
 
Last edited:
With the spring relocate the perches on the axle had to be moved as well. When I set my Demon up I measured from the back side of the torsion bar crossmember by dropping a plumb bob off the sockets for the t-bars. I measured not only drivers to driver rear but driver to passenger side. And the reverse the other way. I dropped the plumb bob off the rear axle flange for the rear. I got within an 1/8" from side to side. This may be an area to look into and measure. Of course the suspension needs to be weight on (jack stands under rear axle) to simulate weight on wheels.
 
cannucky said:
It doesn't say you changed shocks which is required with the ss springs , hard to tell by the photos but the passenger side should be higher than the drivers and at rest the passenger side wheel should be 1/2 inch forward of the drivers side , it's referred to as thrust angle in the books and the increased arc of tge passenger spring causes it . under launch load the spring compresses farther and the wheel mives back into line creating a straight launch.
Click to expand...
At about 2.44 in this video you can see the rear hop with stock springs and jump to the left.

 
Has this car rolled yet? Check for wobble. Are your tires touching the inside of the wheel house?
 
You cannot have positive camber on a solid axle car unless the axle tube is bent. It is simply sitting differently than you are used to.
 
RustyRatRod said:
You cannot have positive camber on a solid axle car unless the axle tube is bent. It is simply sitting differently than you are used to.
Click to expand...

Hey Rusty,

Yes, I'm hoping this is just a noob false alarm. Still learning as I go.

Do you have any thoughts on the upper or lower hole in the front bracket(s). I'm currently using the lower hole. Some have commented that the rear looks to be pretty high.

Thanks,

-R
 
IMO, it will not make a lot of difference whatsoever by changing holes in the bracket. It does however, affect how the car launches more then the actual height.
 
RustyRatRod said:
IMO, it will not make a lot of difference whatsoever by changing holes in the bracket. It does however, affect how the car launches more then the actual height.
Click to expand...

Can you elaborate on the differences in the car launch?

Thanks,
-R
 
It really depends on the car. With the springs in the upper hole, the rear suspension has a little more room to push the springs down and plant the tires more.

But that's all dependent on whether the car had the power to use that extra room.

Also, did you make sure to do your final bolt torquing with the wheels on the ground and torque the U bolt nuts to only 45 LB FT? That's very important.
 
RustyRatRod said:
It really depends on the car. With the springs in the upper hole, the rear suspension has a little more room to push the springs down and plant the tires more.

But that's all dependent on whether the car had the power to use that extra room.

Also, did you make sure to do your final bolt torquing with the wheels on the ground and torque the U bolt nuts to only 45 LB FT? That's very important.
Click to expand...

The car is my first bracket car. I'm new to the sport. I was shooting for 12's and currently my best in the /4 is 12.79 @ 105. Motor is a 408 stroker motor making 430hp and 495ftlb on the dyno. Sounds like the lower hole will be fine based on what you're saying.

I did torque the U bolts to 45 ftlb but did it while up on the stands. I can revisit that now that it's back on the ground.

Thanks,
-Rob
 
I'm unfamiliar with this.... Did it require relocating the perches on the axle?

A simple angle finder will tell you if the wheels are truly cambered. Plumb Bob on a bare rim, from top edge to bottom edge can too.
If it is truly cambered, and you relocated perches, you could have warped the axle with the welding?
 
Not trying to be arguementive but wouldn't the upper hole move the body closer to the snubber, or the tire closer to the upper wheelhouse, thus shortening the available travel ? Either way I doubt it would have much effect on launch and certainly none on thrust angle .
 
67Dart273 said:
THIS. Bending the axle is the only way to change toe or camber on a solid axle
Click to expand...
Tell me about it even after adding a spacer to reduce my thrust angle to 1/2 inch I still have toe in on both sides , another quality piece from the Ahat that did my resto , still trying to bribe Inertia to move the perches on my spare housing so I can build a straight one .But to be specific in my case it's the housing tubes that aren't straight not the axels.
 
Lonewolf3165 said:
You need to explain what you are seeing better. The only way to cause toe in on a solid axle is if you bent the housing, which I doubt.
If 1 side in pointing inward (at the front of the tire) the other side should be pointing outward. As already stated this is called thrust angle not toe.
Measure wheel base on both sides of the car and compare it.
Click to expand...

I used a plumb bob on the wheels and everything looks fine. All the other differences in before/after measurements make sense for SS springs.

Looks like this is a false alarm. Thanks for all the input.

-Rob
 
The heat from welding the new spring pads may have pulled the tubes down some?
 
cannucky said:
Cool now get you some proper length shocks and a snubber
Click to expand...

Looks like the JEGS Super Stock suspension kit

JEGS Part Number: 312-P4120863K1
Super Stock Suspension Kit
1964-76 A-body
All transmissions
2800-lb springs

The kit has Comp Eng 2620's on the Front and Comp Eng 2635's on the rear.
Front - 2620 - Extended Length 16.84" Collapsed Length 10.37"
Rear - 2635 - Extended Length 24.5" Collapsed Length 14.5"

Will have to check mine to see if they match (already have Comp Eng shocks installed).

If they are the correct length, I'll need to change the rear shock setup (currently 50/50 left, 30/70 right) to 50/50 left, 50/50 right. FYI Front shocks are 90/10.

Thoughts?
 
Last edited:
You must log in or register to reply here.
-

Back
Top