rear end whine..

Discussion in 'Transmission & Driveline Topics' started by 71RS6SPD, Oct 7, 2017.

  1. 71RS6SPD

    71RS6SPD Veteran Member

    143
    4
    Nov 14, 2016
    I have about 100 miles on the new setup. Best news is that the
    Pinion angle change has eliminated the high freq vibration yahoo! It's only been tested up to 90 so far. I now have a tire balance issue as I can go faster since the drive line vibes are gone. I could not really go above 70 before and vibes started at 60. Today I had it up to 90 but I think I lost some weights off the wheels as I have a lower freq vibe now. Will test wheels for vibe while off the ground to see if its front or back or both.

    The worst news is that the drive line whine is still there although not as loud. From 50 and up - it fades at higher speeds 80+ and is loudest during slight cruise/acceleration. I am going to ignore it for now as much as I can and hope it fades. if it never goes away - I will put in a new ring/pinion set next year. I will stick with the 4.10's, Love them. 1600 rpm @ 70 in 6th.
     
  2. 71RS6SPD

    71RS6SPD Veteran Member

    143
    4
    Nov 14, 2016
    So I have discovered another issue with the traction bars. I went to check the snubber height and realized that they are touching the spring - and not barely - they are bound up. The ride is no softer either even with the removed leaf. Possibly due to this situation. I guess I will try to cut the snubbers shorter and see what happens. I should extend their length so they hit under the eye and not the 3 inches back where their horrible design places them.
     
  3. big gear head

    big gear head Veteran Member

    5,871
    17
    Jul 30, 2001
    Central City, Ky.
    Competition Engineering J bolt bars hit in the correct place, but the outer shock mounts hit the tires. We put a set on my brother's '70 Z28 and had to cut the outer mounts off.
     
  4. 71RS6SPD

    71RS6SPD Veteran Member

    143
    4
    Nov 14, 2016
    There were other shock mounts that worked on the CE units? They hit under the spring eye?

    I have older lakewood j-bars but I switched to double ubolts as the Lakewood install PDF says to. It says their j-bars are for track use only. They also had a rear safety ubolt unlike the new ones. I had to cut them as they hits the rims. Also had to trim a shock mount to clear rims.

    I removed the snubbers snd cut them down to 1" from 2.5" on a band saw. Now the drivers' side just touches and pass side has 1/4" clearance. Went for a short ride and it did feel better. Will know more tomorrow. I have not launched the car yet as it still has under 1k miles on it.
     
  5. big gear head

    big gear head Veteran Member

    5,871
    17
    Jul 30, 2001
    Central City, Ky.
    They had mounts on both sides of the bars. The inner mounts worked fine, but the outer mounts hit the tires. After cutting the outer mounts there were no more problems. This has been 30+ years ago, so memory may be a little off.
     
  6. Fbird

    Fbird Veteran Member Lifetime Gold Member

    2,386
    87
    Feb 12, 2011
    atlanta, ga
    take your CHEAP traction bars and simply WELD them to your lower shock mount plate. You will find that when you cut off the original lakewood stuff....and slide them forward to the spring eye... they fit wonderfully!! You can also clamp them up with the snubber on, weld them, then take and cut about 1/2" off your snubber ;)
     
  7. 71RS6SPD

    71RS6SPD Veteran Member

    143
    4
    Nov 14, 2016
    So I am sure frustrated. Spent 1200 on all new internals but did not replace the gears as there was only 700 miles on them. I now have a noisy rear end. It howls under accell from 35 and up. I think its getting louder too. Can't ignore it much longer.
     
  8. SRGN

    SRGN Veteran Member

    258
    67
    Feb 20, 2009
    Central NJ
    Once a pattern wears into the gears, its difficult, if not impossible, to get rid of the noise even after you fix the setup issues.
     
  9. 71RS6SPD

    71RS6SPD Veteran Member

    143
    4
    Nov 14, 2016
    Yes ordering new gears today.. I think I will try 390s. I've been loving the 410s but I need wider tires. It spins the 245s really easy. I have to avoid full throttle in first or spin. At the current rate I will wear these out soon. It's fun for sure.
     

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