Fourth Gen F-Body Torque Arms

Discussion in 'Suspension, Steering, Brake & Wheel Topics' started by danbrennan, Jun 26, 2007.

  1. danbrennan

    danbrennan Veteran Member Lifetime Gold Member

    2,745
    13
    Mar 13, 1999
    Brighton, MI
    Why did the third and fourth gen f-bodies need torque arms, while our second gen f-bodies didn't? Did the leaf springs in the second gens serve to take the place of the torque arms? If that was true, why doesn't my '72 442, with rear coil springs, also need a torque arm? I'm a little puzzled about what the torque arm does.
     
  2. ColdBastrd

    ColdBastrd Veteran Member Gold Member

    4,049
    0
    Jul 9, 2002
    Orange County NY
    It controls wheel hop during acceleration. It helps plant the rear tires to the ground in acceleration and braking. Ever put a lot of juice to the stock rear of an old A-body like your 442? Bet that the rear wheel will bounce like crazy. There are kits to improve that now. With leaf springs, the torque is loaded differantly, hence traction bars.
     
  3. LRoberts73

    LRoberts73 Veteran Member

    177
    0
    May 10, 2004
    Durham, NC, US
    The torque arm resists the twisting motion of the rear axle assembly during acceleration and deceleration. You are correct, with a leaf spring rear suspension, the forward portions of the leaf springs act to resist those same movements.

    IIRC, a '72 Olds 442 has a four link rear suspension.. two lower trailing arms, and two upper. This configuration does not need a torque arm... the trailing arm geometry is designed to allow the arms to absorb the twisting motion. This is called a 4-link suspension system.

    I'm guessing that the fourth gen Camaro does not have upper trailing arms in the rear, (I can't remember exactly how they are set up). So, with two lower arms and a torque link, you have a 3-link suspension. The long trailing arm is needed because the two lower trailing arms alone do not handle the twisting motion sufficiently.
     
  4. tom3

    tom3 Veteran Member

    10,615
    40
    Aug 1, 1999
    ohio
    I think it has to do with a unibody compared to a full frame car. The older cars with the frame were stout enough to have the upper control arms while the unibody made do with the control arm back to the tranny with only the lower trailing arms. Pretty good setup I've always thought, keeps the wheels planted and the drive angles correct.
     
  5. Ian76LT

    Ian76LT Veteran Member

    760
    0
    Aug 10, 2001
    Hillsborough, NJ
    LRoberts73 is right, the third and fourth gen F bodies have two lower control arms and a torque arm.
     
  6. Wouldabin

    Wouldabin Veteran Member Lifetime Gold Member

    they also have a panhard bar (parrallel to the rear) in addition to the torque arm and lower trailing arms.
     
  7. danbrennan

    danbrennan Veteran Member Lifetime Gold Member

    2,745
    13
    Mar 13, 1999
    Brighton, MI
    I completely missed that the Formula doesn't have upper trailing arms. Thinking about the axles trying to wind up, I think I understand now. Thanks.
     
  8. BigAls87Z28

    BigAls87Z28 Veteran Member

    357
    0
    Jul 8, 2003
    Ocean Twp. NJ, USA
    Its design comes from the X-Body of the late 70's. Third/4th gens have a Torque arm that attaches from the back of the trans tail shaft to the pass. side of the center diff. Then there are 2 lower control arms, 2 shocks, 2 coils prings, and a panhard bar that locates the rear. This set up was done to enhance the handling of the third gen when it first came out since performance as of 1982 was a little sad. So to boost the brand new for 82 Camaro's performance angle, the handling was turned up. Third gen also uses a strut front end with only one lower control arm, 4th gen uses an SLA with a coil over type shock system, but from the trans back, its still a third gen.
     
  9. danbrennan

    danbrennan Veteran Member Lifetime Gold Member

    2,745
    13
    Mar 13, 1999
    Brighton, MI
    I'd read the back half of the fourth gens was pretty much the same as a third gen, but I never had a third gen F-body, so I didn't know first hand. I remember reading third gens had a strut-type front suspension, and was surprised when I looked at this '95 Formula that they had went back to SLA. Not disappointed, though. Thanks again.
     
  10. BigAls87Z28

    BigAls87Z28 Veteran Member

    357
    0
    Jul 8, 2003
    Ocean Twp. NJ, USA
    Odd part is...they are going back to a strut front end for the 5th gen...but a multi link IRS for the back. w00t!

    Yeah, third and 4th gens share rear parts. When you look for rear suspension parts, you will see the years going from 82-02.
     
    Last edited: Jun 27, 2007

Share This Page