JOMJ87 Posted June 28, 2007 Share Posted June 28, 2007 OK so some of you know i am doing F/R axle swaps to a 30/44 combo with 4.88s. Anyways i have had alot of issues and most are self caused but a few were just flukes. Now i have a big one!!!! OK i got the front in after 2 long nights after work. I took it for a test drive and as soon as i hit 47 mph i got the dreaded death wobble. Now it only happens on ruff roads and at 47 mph. Any faster or slower it don't do it and if I'm on smooth road it is fine. Well First off the alignment is off and i know it is. also the pinion angle is off because of guestimated Control arm lengths and the trac bar may be off a tiny bit. I know that sounds bad and i prob wasnt smart in driving it but i needed to know if it was ok to drive to work Tomm. morning. Obviously i need to fix these issues before It gets driven any more. But Second i have only heard of DW coming from loose or old joints or linkage not misalignment. so my questions follow... Can all the alignment issues cause death wabble?? Does anyone with a good alignment know the degree setting of any nice easy to get to flat spot on there Front axle to mirror mine from??? Whats the easiest way to check the trac bar alignment?? Thanks alot for any and all replys. I just need to get this taken care of and i need to know if i need to plan to buy parts if its turns out misalignment don't cause DW. Cause i already have to get a new front D-Shaft. Cole Link to comment Share on other sites More sharing options...
Tracker Posted June 28, 2007 Share Posted June 28, 2007 I've done a couple track bars like this: >Steering dead-ahead straight and wheels off. >Tape a weighted piece of string to your flare or fender, with the string centered to the axle. This assumes both sides of the truck are semi straight or at least not caved in. >Measure the distance from the string to the axle on both sides and adjust the track bar until they are equal. If you know the thread count on the track bar you can do a little math and stick it with the first adjustment. Link to comment Share on other sites More sharing options...
pingpong Posted June 28, 2007 Share Posted June 28, 2007 I am willing to bet that your alignment is causing your DW.... it is more then likely a combination of being toed in and caster being off Link to comment Share on other sites More sharing options...
CWLONGSHOT Posted June 28, 2007 Share Posted June 28, 2007 The thing that rings the loudest for me is the MPH. Tires begin to need balance at about 45MPH. Your problem starts at 47MPH. I would start with tire balance or a bad tire. There are many many "fixes" for DW. Truth be told it can be a number of things and with older trucks it usually is a combo of slightly loose worn things causing it. One thing is a fact, SOMETHING must cause it. Usually a bump or an out of balance tire. DW doesn't just happen, its caused. From there it can be anything mentioned here. The ONLY way to find it is roll up your sleeves and get to work!! Check and double check EVERYTHING! CW Link to comment Share on other sites More sharing options...
Eagle Posted June 28, 2007 Share Posted June 28, 2007 There are so many possibilities regarding DW that I wouldn't know where to start. And there's no agreement among Jeepers. I'm firmly in there with CWLONGSHOT -- something has to set off DW, and IMHO that something is USUALLY tire balance. But once it starts, other factors may play into how badly the problem escalates. I've driven my '88 XJ for thousands of miles with a front tire that was out of balance and would start jumping at 55 MPH -- and I could drive right trhough it until it smoothed out at 65. And I've head DW in the 88 MJ that was so bad at 50 MPH that there was no possibility of even TRYING to drive through it. Caster angle is a big one. You need probably 7 or 8 degrees of caster, but if you're lifting then you have to balance caster angle with pinion angle, and you may have to settle for around 6 degrees and hope for the best. Another point is that DW is a harmonic. The wobble usually starts in one wheel. Sometimes, like with my XJ, it stays there and never becomes DW. It becomes DW when a wobble or shimmy in one wheel is transmitted to the opposite wheel and starts that one shimmying at the same frequency. Why does one vehicle do it and another not? Could be that one has more loose tie rod ends, etc. Could be how well the shocks dampen the oscillations. Could be that the spring rate (coil springs have a natural frequency) happens to coincide with the frequency of the shimmy. Could be warped brake rotors. Start with tire balance. Beyond that, it ain't easy. Link to comment Share on other sites More sharing options...
UNL1MTD Posted June 28, 2007 Share Posted June 28, 2007 Is the wobble like the steering wheel is ripped out of your hands and the front end feels like its going to be torn from the truck? Or is it the wobble that the steering wheel makes from way out of balanced tires? In all my experiences with wobble (death/regularish) its been out of balance tires setting off another component that either was not tight or the bushing/joint had failed. I've had a loose control arms once and a loose trackbar about 5 times. If the trackbar has any play in the joints or isn't torqued to spec, its going to cause some wobble. Rereading your post, if you just sorta guess at all your suspension link lengths then that sounds like a good place to start, since there is a good chance they aren't right. Link to comment Share on other sites More sharing options...
JOMJ87 Posted June 28, 2007 Author Share Posted June 28, 2007 OK thanks alot guys. I was just wanting to see if the linkages COULD cause it so knowing that i feel better cause I'm sure after a few hours of work i can get it right. It isnt DW so bad as to jerk me out of the road but the steering wheel does jerk back and forth pretty good. Out of balance tires have never felt like this. I will work on the suspension links and see what i can get done with it. EAGLE where do i mesure to check the castor angle??? I have a degre finder but i don't know where they take the messurement from to check it. I'm sure its out now that i have looked it over today. Thanks again Cole Link to comment Share on other sites More sharing options...
CWLONGSHOT Posted June 28, 2007 Share Posted June 28, 2007 They say a picture is worth a thousand words... :D 8) . CW Link to comment Share on other sites More sharing options...
JOMJ87 Posted June 29, 2007 Author Share Posted June 29, 2007 PERFECT thanks CW Cole Link to comment Share on other sites More sharing options...
HellCreek Posted June 29, 2007 Share Posted June 29, 2007 Hi, CWLONGSHOT, I've got to agree with the others in all respects, but I would check the balance first. On my 89 Sport Truck, I had just installed our 3 inch kit and test drove it. At about 45 mph the steering wheel was almost ripped out of my hands (I've got manual steering, so it was probably amplified). I took it to the tire shop and they balanced all four wheels with no improvement. I checked everything for tightness and was satisfied there, so I took it to another tire shop. They had what they called a "Road Force" balancing machine. This machine checks the balance of the tire while pressure is being applied by a steel roller. After checking the tires on that, I wound up buying new tires, since the old ones had such heavy spots that they could not be balanced properly. That fixed the problem, and I can drive safely now at any speed, within reason - of course. Link to comment Share on other sites More sharing options...
HellCreek Posted June 29, 2007 Share Posted June 29, 2007 Sorry, this was addressed to the wrong person. It should have been directed to JOMJ87, but you get the idea. Thanks, Tom Link to comment Share on other sites More sharing options...
JOMJ87 Posted June 29, 2007 Author Share Posted June 29, 2007 Well my only concern is i drove last week at 65 and had zero vibs so i don't think its the balance. I also balenced the tires myself on the machine. I am going to get the alignment of all the suspension componets right first and then if there is still an issue i will find a shop to balance the tires. Thansk for the input though Cole Link to comment Share on other sites More sharing options...
JeeperjohnfromPA Posted June 29, 2007 Share Posted June 29, 2007 I had the the woobles in my YJ, never could figure it out. Usualy when it would happen I would drive through it, or slow down for a bit, it would come and go arround 60-65mph. Anyhow one day think it was arround 200k miles the front left rotor seperated from the hub. Once I replaced the front rotors, the old beast lost it's wobbles. Turns out the recall for the front rotors that I ignored from way back was due to composite rotors. They were made from two different grades of metal, and in the northern part of the country,(salted winter roads), they were realy screwing up. Well your truely tries not to use the brakes :evil: I down shift alot,:driving: and always cleaned up after a good romp in the mud, so the things lasted me that long. :D So if you have the old composite type rotors :dunno: Maybe you wanna take a look at them too. Link to comment Share on other sites More sharing options...
mfpdm Posted June 29, 2007 Share Posted June 29, 2007 I've got to agree with the others in all respects, but I would check the balance first. I took it to the tire shop and they balanced all four wheels with no improvement. I checked everything for tightness and was satisfied there, so I took it to another tire shop. They had what they called a "Road Force" balancing machine. This machine checks the balance of the tire while pressure is being applied by a steel roller. I had my new tires balanced twice as well on two different types of balancers. My problem was that I kept throwing the weights off, which a 65 mph scares the hell out of you when it hits the fender then shoots out and hits the car next to you. :eek: I finally solved that problem with wheel balancers from here. http://www.centramatic.com/ Link to comment Share on other sites More sharing options...
88swampedmj Posted June 29, 2007 Share Posted June 29, 2007 leaf springs help with that lol Link to comment Share on other sites More sharing options...
CWLONGSHOT Posted June 29, 2007 Share Posted June 29, 2007 I finally solved that problem with wheel balancers from here.http://www.centramatic.com/ These are THE BOMB!! I have them on my TJ...ZERO problems since install!! CW Link to comment Share on other sites More sharing options...
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