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Things To Improve Stability On Short Wheel Base Cj5

Discussion in 'Intermediate CJ-5 and CJ-6 Tech' started by Mazinger, Apr 2, 2017.

  1. Apr 2, 2017
    Mazinger

    Mazinger New Member

    United states
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    Hey guys another thread im starting i need some ideas to improve the stability and minimize rollover change on my 1973 CJ5. here are some ideas i have not sure if they would improve stability

    1. i was thinking of doing wider tires and 4.5 backspacing wheels would this extend the wheelbase on the jeep? would using heavier steel wheels instead alloy keep the jeep firmer on the ground?

    thats what i have so far do you guys have any ideas to improve the vehicle in this area?
     
  2. Apr 2, 2017
    PeteL

    PeteL Member Sponsor

    Hills of NH
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    In correct terms that would increase the track, not the wheelbase.

    In over fifty years I've never come close to rolling a CJ5.
    To answer your question, the biggest thing you can do is drive sensibly.

    Although I will confess to doing a lateral 360 in an XJ that one time...
     
    dnb5853 and cookieman like this.
  3. Apr 3, 2017
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    Pete, you just aren't trying hard enough. :D

    The biggest single improvement you can make in the stability of a jeep is the addition of a front anti-sway bar. They weren't offered as factory equipment until much later, so some custom fabrication and ingenuity would be in order to make one work.
     
  4. Apr 3, 2017
    tarry99

    tarry99 Member Sponsor

    Northern California
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    Lower Center of Gravity.............coupled with a more compliant suspension.
     
  5. Apr 3, 2017
    PeteL

    PeteL Member Sponsor

    Hills of NH
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    M38A1 had a sway bar ("front stabilizer"). Ought to fit a CJ5.

    But ironically, that would make the suspension less "compliant." You pays your money and you takes your pick.
     
  6. Apr 3, 2017
    johneyboy03

    johneyboy03 The green beast

    Quebec, Canada
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    Front say bar from a 1976 and up jeep cj. You can make some disconnect for the trail.

    There also the steering box brace that is a good addition to help the steer wander.

    As for the offset rim, it may help but it will put some bad stress on the bearing.

    Also frame condition will be something to check.
     
  7. Apr 3, 2017
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member Sponsor

    Tantallon, Nova...
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    I had a sway bar on order for Tonk, didn't need it after I adjusted the tire pressure.

    I'd say good shocks will help but it's more a case of bad shocks will cause problems.

    Stability issues back in the day were *way* over reported.

    From "It Didn't Start With Dateline NBC" (National Review 6/21/93) :

    In December 1980, 60 Minutes reported that the small army-style "CJ" Jeep was dangerously apt to roll over--not only in emergencies but "even in routine road circumstances at relatively low speeds." A Jeep is shown crashing. "We'll get to precisely what the conditions were that made that single-car accident happen in a moment," promises Morley Safer.

    The footage, it seems, is of tests run by the Insurance Institute for Highway Safety and was produced in collaboration with a CBS film crew. It shows Jeeps going through what appear from a distance to be standard maneuvers. Safer describes the first. "It is something called a J-turn: a fairly gentle right-hand turn that a driver might make if he was going into a parking lot." The Jeep flips over. Safer concedes that "it does not happen every time," and a good thing too, since if it did the nation's parking lots would be cluttered with overturned Jeeps spinning their wheels helplessly like so many ladybugs.

    The camera then shows a second test run, "an evasive maneuver, as if the driver is trying to avoid something on the road." An unwanted object is shown obstructing a roadway, lending a you-are-there touch. "The driver would pull out of his lane to the left, go around the obstacle, then pull back to the right into his lane," explains Safer. The Jeep flips over again. Dummy occupants, outfitted in plaid shirts and farmer caps, tumble out to their doom.

    Now by this point even trusting viewers might have felt a gnawing canker of doubt. Jeeps may be awkward, hard-to-control vehicles, but do they really do that? After all, skillful stunt drivers can tip over many sorts of vehicles on purpose. Chrysler/AMC, which makes the Jeep, sends out a tape in which this trick is performed on various stock cars and trucks, including a Toyota Corolla, a Ford Bronco, and a Datsun 4 x 4 pickup.

    Tantalizingly, Safer seems to share or at least foresee these same doubts. He chats with two guests from the Insurance Institute. "I'm trying to think of some of the things that AMC would accuse you of doing if they were here watching these tests along with us. For example, putting the vehicle through the sort of turns and the sort of stresses that it just would never be put through in normal real-world driving on the road." The guests are reassuring, if that is the right word: yes, the test conditions "do occur in the real world," at least "in panic situations." AMC, for its part, is quoted as saying it suspects the tests of being "contrived to make the Jeep turn over." But the detail stops there.

    Too bad. Viewers might have profited by knowing, for example, that testers had to put the Jeeps through 435 runs to get 8 rollovers. A single vehicle was put through 201 runs and accounted for 4 of the rollovers. Make a car skid repeatedly, Chrysler says, and you predictably degrade tire tread and other key safety margins.

    Was the J-turn, or for that matter the evasive maneuver, "fairly gentle"? The Jeep was occupied by robot drivers that were twisting the steering wheel through more than 580 degrees of arc, well over one and a half full turns of the steering wheel. (Do not, repeat _not_, try this cruising in your own vehicle.) More striking yet was how fast and hard they jerked the steering wheel: in one case, at a rate in excess of five full turns a second. A study for GM, apparently unrelated to the Jeep affair, found that average drivers' maximum steer rate in emergencies reaches 520 degrees/second, while expert drivers can reach 800; rates above 1,000 degrees/second seem to happen mostly when drivers lose control. The robots used rates of from 1,100 to 1,805 degrees/second in the obstacle-avoidance maneuver. They were also gunning the accelerator-- not what you or I might do if a crate of hens suddenly fell in front of us on the highway. (An Insurance Institute internal memo had proposed arranging variables "to ensure rollover.")

    An investigative engineer at the National Highway Traffic Safety Administration later wrote that the tests' validity was "questionable" given their apparently "abnormal test conditions and unrealistic maneuvers," and also found signs that the vehicles' loading had been "manipulated in combination with other vehicle conditions to generate worst-case conditions" for stability. The "vehicle loading" issue was clarified by the testers' own internal report, which was not disclosed at the time but emerged later in litigation. In their report, the testers say that at the request of Insurance Institute personnel, they had taken the step of _hanging weights in the vehicle's corners_ -- inside the body, where they were not apparent to the camera
    .

    I'm not going to argue that a jeep isn't more tippy than a passenger car, but they are not death traps waiting for the chance to kill you by spontaneously flipping upside down while halted at a stop sign. :whistle:

    H.
     
    Last edited: Apr 3, 2017
    heavychevy likes this.
  8. Apr 3, 2017
    PeteL

    PeteL Member Sponsor

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    Mighty be worth considering that CJ's were designed to ride on bias-ply tires. Less sidewall sway and squish than radials.
     
    1974Sixer likes this.
  9. Apr 3, 2017
    Twin2

    Twin2 wasn't me Sponsor

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    shortly after this viewed . I was notified by GEICO . they would no longer insure jeep on my policy :mad:
     
  10. Apr 3, 2017
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member Sponsor

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    These are NDT bias ply tires, I had them at 22 PSI for some reason & I wasn't driving so much as diving. Popped them up to 28/26 front/rear PSI & now he rides like he's on rails.

    Very bumpy rails but rails non-the-less.

    H.
     
  11. Apr 3, 2017
    Mazinger

    Mazinger New Member

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    these are awesome ideas thanks guys yeah i saw that infamous 60 minutes report. do the swaybar from a 76 bolt on?
     
  12. Apr 3, 2017
    johneyboy03

    johneyboy03 The green beast

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    Width is right for the 76 sway bar, but frame braket wont fit over 75- frame. But making some custom braket is pretty easy for having it done on my 75 before.
     
  13. Apr 3, 2017
    Mazinger

    Mazinger New Member

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    When you get a chance could you take a picture of the bracket and what the sway bar looks installed thanks
     
  14. Apr 3, 2017
    zila

    zila I throw poop

    Rock Springs,...
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    Those old jeeps and I mean every one I ever rode in are devious.. They all seem like they are about to tip over on side hills etc. Don't know why but it is an illusion. Even on two track trails you get one wheel in the rut and one not. The wife is whinin about it etc...But it is a long way from tipping over..
     
  15. Apr 3, 2017
    ITLKSEZ

    ITLKSEZ Volvophilic

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    This is what I wanted to get to last night, but I only had a second to post. Not much, short of lowering the center of gravity or adding wider axles, will increase the actual tipover point of a vehicle. 95% of that "tippy" feeling you feel is in your head, multiplied by the lean caused by narrow springs that are mounted close together (allowing more than average lean in off-camber trails or high speed turns). A sway bar will limit the lean/body roll and give a more balanced feel.

    They really are surprisingly difficult to tip over.
     
  16. Apr 3, 2017
    timgr

    timgr Jeepin' Nerd Sponsor

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    Factory backspacing is about 3.75". If you want a wider track, you reduce the backspacing, not increase. Wheels with 2.5" backspacing are available. This will give you a 2.5" wider track.

    Center of gravity matters. More lift will make the Jeep more likely to tip over. Wide tires make a tip over more likely, since you are more likely to roll than slide on pavement. My feeling is that a more supple suspension (softer) will make roll over more likely, since the body roll will be larger. The original Jeep design controlled body roll by using stiff springs, which mostly overcame the extreme inboard mounting of the springs. You need the inboard mount with leaf springs so that the turning radius is not huge. The '76-up Jeeps mount the rear springs more outboard to better resist body roll.
     
    Last edited: Apr 3, 2017
    1974Sixer likes this.
  17. Apr 3, 2017
    Daryl

    Daryl Sponsor Sponsor

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    I swap out front axles on pretty much every old Jeep I build just because the Dana 30 is so much simpler to work on, but it is 3 inches wider then a 25 or 27. Maybe it does make a big difference because it really is pretty hard to tip over a Jeep unless you do something to put yourself into a bad situation. In street driving and even moderate trails, the chance of tipping over is very low to the point that Jeep didn't even start to put in "rollbars" until 1969.
     
  18. Apr 3, 2017
    nwedgar

    nwedgar Now with TBI!

    Newnan, Georgia
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    What Tim said. I bought steel "D" window wheels with 2.5" backspacing and it does help the stance. I made sure my bearings were high quality and have plenty of grease, I don't think the reduced backspacing has been detrimental at all. But still, the springs mounts are only...what...28" apart?

    I think adding a sway bar would help road manners tremendously. Not to mention making sure that all front end components are in very good repair and adjusted properly.
     
  19. Apr 15, 2017
    Mazinger

    Mazinger New Member

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    I believe my cj5 is lifted not sure about how can i go about finding out if thats the case?

    I also noticed the way my 258 sits in the engine bay is slightly slanted towards the front is that normal all the motor mounts seem to be okay
     
  20. Apr 15, 2017
    Mazinger

    Mazinger New Member

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    Is there a way i can measure the height to see if the jeep is lifted if someone could provide me with a stock height of a 73 cj5 maybe?
     

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