Springs n suspension

[shipahoys_antique_and_collectable_centre]

Just wondering if anybody knowledgeable can help advise me -  Have an old VC (Classic!) V8 Commodore which has only just started rubbing the rear tyre on one side, every time I hit a dip or bump on the road. It's only just occured in the last few days, and the one side is definitely sitting lower than the other, and worse when I have passengers in the rear. I am thinking that replacing the springs will hopefully cure the problem, and perhaps new shocks too.  Is there any way to confirm that the springs are no longer serviceable? Also, If the one side does require replacing, I presume that both sides should be done?  Many thanks Paul

[viewmont1071]

Springs generally become "straighter" rather than having a described definite arc when they "lose their set".

The springs may be unserviceable however a competent blacksmith or boilermaker may be able to reset and retemper your

springs.

Odds on bet is that you have lost the set in both and have a broken centre bolt in one spring pack try Lovells, Kings Springs or Pedders

http://www.lovellsauto.com.au/docs/cat_passcomm13.pdf

copy and paste from the link above

Leaf Springs (Laminated Springs)

As per Lovells coil springs, leaf springs are designed as a superior replacement part for mass produced O.E.

(Original Equipment) leaf springs.

Practically all leaf springs used on cars, 4x4’s andtrucks are of the semielliptic type.

The semi elliptic spring has function of not only a spring, it can dampen vertical deflection, supports the vehicle, positions the axle and cushions both driving torque and brake reaction.

Lovells leaf springs are again manufactured using premium quality OneSteel micro alloy steel. Leaf springs are cambered on specially designed machines before being assembled, rate tested and inspected.

All leaf springs are enamel dipped in Lovells Navy Blue ready for despatch

[viewmont1071]

The springs need to be replaced as a set

screen shot of Lovells VC combinations

                                                                         fronts                                                                           rears

[shipahoys_antique_and_collectable_centre]

Thanks Viewmont!  The springs on the Comm are Coil though, not leaf.  It originally had factory fitted pump up shockers, but seens to just be plain shocks now.

[joz*garage]

poor shocks can wear your tyres out, front or rear

have you checked them?

[shipahoys_antique_and_collectable_centre]

Gday Joz, I initially thought that it may be the shockers, but I dont think that woud be reason for the car to drop?  From what I can ascertain from my basic knowledge, the springs hold the car in place and the shockers just stop the springs from making it bounce around. 

[joz*garage]

hi barn, i initially thought the same with my vc commodore. i didnt investigate it though cos it wouldve ate into my profits and passed it on. gee it drove very good hey.. 202 4sp & was way better to drive then a uc 202 torana that i had.

anyway, have you pushed down with both hands on each corner and is it very springy?

(there are suspension joints around that will give you a free appraisal, btw)

[viewmont1071]

The theory is still the same though whether leaf or coil.

The spring holds the weight while the shock absorber dampens the bounce.That's why suspension is given the name it"'suspends" the cars weight

If the car is sitting low then the spring has lost its temper. no ifs or buts. If the tyre is wearing unevenly then you also need to fit

track rod  and trailing arm bushes when  the springs are done 

If it is a variable rate spring (the coils are not set equidistant) then it is harder to retemper.

Heat is created when a spring actuates which sort of recreates the original temper process that created the "spring" then over a long period the spring loses its tension. 

To retension the spring the coil spring needs to evenly heated to black hot and then quenched in oil a number of times. It is an

exacting process and if incorrectly tempered will casue the spring to become brittle and extremely dangerous if refitted.. I have a

vb/vc  factory manual somewhere I will see if I can find it

[viewmont1071]

VB rear suspension diagram

[viewmont1071]

Scan above of the factory air shock system. rthis however it  is not load bearing. Some styles of "air suspension" systems like earlier Subarus were true "airbag" systems. Some enthusiasts modify their suspensions by removing the metal springs and inserting airbags this allows them to adjust ride height. Earlier Citroens had what is called an oleopheumatic suspension which could rise and fall but used oil rather than air to control ride height that was pumped into and out of the system.

While inserting air into the shock absorbers of the commodore system  will control to an extent the rear bounce caused by heavier loads and slightly raise the rear when fully pumped they are not load bearing and leave that  job to the springs.

I think the diff codes are the same for VB and VC if you look at your build plate for the diff code then this chart should tell you what ratio diff is fitted