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unsprung weight????

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by mudddog91, Jul 24, 2001.

  1. mudddog91

    mudddog91 1/2 ton status

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    Got a question about unsprung weight.......Ive got a 3/4 truck
    I know its not a k5 but maybe someone in here can help anyways?????Ive taken the bed off and fabbed a steel flat bed and cut about a foot off the rear of the frame.Its got a 14 bolt ff and 33's right now and the problem im having is that when ridin down the road a @ 45-50 mph if i hit a bump or series of bumps my rear end bounces and oscillates like crazy causing me to pretyy much be out of control!!!!!!Its like the left tire bounces up and then the right tire bounces up when the left tire bounces down and it continues to get worse until i hit the brakes and slow down to about 30 mph.
    Has any one had this problem?It seems like the unsprung weight is greater than the sprung weight.Is there any way to counter act this? maybe some type of ladder bar or traction bar?Its got axlewrap ;ike nobodys business because the springs are soft and its got 3 " blocks.help please!!!!!!!!!
     
  2. MaxCrack

    MaxCrack 1/2 ton status

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    I'm thinking ladder bars. But then I've only read about this problem, and have no first hand experience.



    That's because I'm the devil.
     
  3. gpd4

    gpd4 Registered Member

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    I ripped my tie rod off on the pass. side a few months ago, and drove it for a few days w/o the steering stabilizer. I had the same problem until I put it back on. Maybe your's is just worn out...

    '85 Blazer... 9" lift... 35-12.50 BFG AT's...LOTS of rust
     
  4. CV202

    CV202 1/2 ton status

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    Rancho makes kicker shocks that are basically a cushioned version of traction bars. They work pretty good at keeping the rearend planted on the ground and help tame washboard.

    Why do people keep calling it a Bronco!!!!! [​IMG]
     
  5. Triaged

    Triaged 1/2 ton status

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    Look into the shackles made by BFG. They are called "velvet-ride". It is a shackle that is 2 pices with a rubber spring in between the 2. That is exactally what they are made for.

    '71 Blazer CST w/ a 400sbc, 4" lift, 36" Supper Swampers, and alot of rust
     
  6. Twiz

    Twiz 1/2 ton status

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    I'm with triaged on the velvet ride shackles.
    I have a buddy that did the 'gass body Bummer converstion- and it kindof sounds like the same problem he had. He installed the velvet shackles and said it helped out alot.

    Twiztid
     
  7. 6.2Blazer

    6.2Blazer 1/2 ton status

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    I don't think that any type of ladder bar or kicker shocks will resolve the problem when hitting bumps going down the road. These types of devices are designed to prevent rotational movement of the axle when a lot of power (torque) is supplied to it (like under hard acceleration).

    My first thought when I read about a flatbed and bobbed frame was that it still had the original stiff 3/4 ton springs on the back, and with very little weight on them they really weren't flexing any which would cause the tires to kind of bouce when going over bumps......but then you mention really soft springs.

    Since you say soft springs, I then would be suspicious of the shocks (you do have shocks on it, right??). You would probably need a set of shocks that were fairly stiff in order to control the heavy rear axle with the soft springs.
     
  8. mudddog91

    mudddog91 1/2 ton status

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    aCTUALLY I t doesnt have shocls on it right now.........Will this stop this from happening?The leaf spring pack is the original minus 2 leafs with a 4 " block and shackle flip.
     
  9. Triaged

    Triaged 1/2 ton status

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    YES! Put shocks on it!

    '71 Blazer CST w/ a 400sbc, 4" lift, 36" Supper Swampers, and alot of rust
     
  10. bigredblazer

    bigredblazer 1/2 ton status

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    First of all put some qualityshocks on it. Ditch the lift block, and even though you took two leaves out of the spring pack, my guess is it's still too stiff. Since you bobbed it, and made a flat bed ( depending on the weight of the flat bed) you took off a lot of weight. Look for some good springs paying attention to the spring rate, and maybe some adjustable shocks. Good luck. Jon

    Blazin' Trails ORD Style
     
  11. Twiz

    Twiz 1/2 ton status

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    No shocks on it! Jeez, well what do you expect....

    Thats what I get for "assumeing"

    Twiztid
     
  12. 6.2Blazer

    6.2Blazer 1/2 ton status

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    They just ain't for show!!!!!!
     

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