WahooSteeler Posted December 14, 2019 Share Posted December 14, 2019 Had my truck 10+yrs. Was DD for my son last 18mos before he went to college, otherwise probably was driven 2-3k/year. Been running 31s since right after I bought it. Originally put on mild lift with ZJ V8 coils and pucks, WJ LCAs, everything else stock, maybe 2" lift. NEVER had death wobble at any speed, not even a hint. Been accumulating parts for HD steering upgrade for couple of years, OE track bar recently broke so went ahead and replaced ALL front end components with new parts I've accumulated along with a little more lift, probably 3.5" now. OME 2930 coils, 1.75 pucks, fixed LCAs for 3-4" lift, adj UCA, HD adj track bar, HD XJ drag link, ZJ V8 tie rod, new shocks, new steering stabilizer. The only parts that are not new on the front end are the axle bushings for UCAs and ball joints on steering knuckles. Probably put a few hundred miles on it since these were installed, no problems at various speeds up to 70mph. Yesterday installed extended shackles on rear to level it out. Today, under hard acceleration, death wobble at @45mph!!!! Under normal acceleration up to 60mph it did not happen, but then happened as I slowed down, again @40mph. I can't even say how upset I am. First because i have never had DW even with OE 227k mile steering components, and second because lately it seems like every time I fix one thing another thing happens. I don't have the time or tools to do this type of work and it is turning in to a money pit. I am at my wits end.......anxious for feedback since everything is new. Confused and frustrated. Link to comment Share on other sites More sharing options...
Eagle Posted December 14, 2019 Share Posted December 14, 2019 Caster angle. The longer shackles changed it. Link to comment Share on other sites More sharing options...
Jeep Driver Posted December 14, 2019 Share Posted December 14, 2019 7 minutes ago, Eagle said: Caster angle. The longer shackles changed it. Agreed. I would also suggest your toe changed ever so slightly also......just enough. Link to comment Share on other sites More sharing options...
WahooSteeler Posted December 15, 2019 Author Share Posted December 15, 2019 Thanks guys.......so the solution is?? Isn't the caster difficult to adjust on MJ's? Link to comment Share on other sites More sharing options...
Eagle Posted December 15, 2019 Share Posted December 15, 2019 I don't know if caster is the problem without knowing what the angle was before you lifted the rear. We do know that caster angle can be a contributing factor. It's not difficult to adjust, but it is difficult (let's just say impossible) to measure at home, in your garage or driveway. Take it to a front ed shop and have it aligned. Link to comment Share on other sites More sharing options...
Eagle Posted December 15, 2019 Share Posted December 15, 2019 4 hours ago, Jeep Driver said: I would also suggest your toe changed ever so slightly also......just enough. True. 'Tis possible. Link to comment Share on other sites More sharing options...
Andy in Pa Posted December 15, 2019 Share Posted December 15, 2019 Did you get it aligned after changing all those front end components? If not, that is a contributing factor. Castor angle has been mentioned, and is likely why you got DW. If you look at the inner C's on your front axle, they should be tilted back around 8-12 degrees, like this "/" if looking from the tire side. IS the steering really light, almost wandering a bit? If so, the inner C is too close to this "I". Since you have adjustable UCA's, you should be able to adjust more castor into the front end. Changing the lift in the back can actually cause this too, because it rotates the axle counter=clockwise just a tiny bit, which decreases castor. Also keep in mind that now that you have gotten DW, it may have loosened other components in the front end too. Track bars are particularly susceptible to this. Take a really goo look at your track bar bushings. I have had brand new HD track bars with a poly mount at the axle end (installed for only a few months) fail after a bad case of DW. Link to comment Share on other sites More sharing options...
omega_rugal Posted December 15, 2019 Share Posted December 15, 2019 10 hours ago, Andy in Pa said: Track bars are particularly susceptible to this yep, even if it´s barely loose it WILL cause DW... Link to comment Share on other sites More sharing options...
WahooSteeler Posted December 15, 2019 Author Share Posted December 15, 2019 Yes, shop aligned it after installing front end components. I will check and re-tighten everything today then take it back to the shop tomorrow to do an alignment again now that the rear is lifted, and see about adjusting the UCAs. Link to comment Share on other sites More sharing options...
Pete M Posted December 15, 2019 Share Posted December 15, 2019 2 hours ago, omega_rugal said: yep, even if it´s barely loose it WILL cause DW... *could* would be a better word. I've driven on a few bad/loose trackbars and have never experienced DW. Link to comment Share on other sites More sharing options...
omega_rugal Posted December 15, 2019 Share Posted December 15, 2019 8 minutes ago, Pete M said: *could* would be a better word. I've driven on a few bad/loose trackbars and have never experienced DW. who knows, i couldn´t figure out the problem until i shook the track bar hard and noticed it moved, retighen it, problem solved mine is bone stock, no lift, no anything, changing the suspension in any way introduces more variables to the ecuation... Link to comment Share on other sites More sharing options...
Pete M Posted December 15, 2019 Share Posted December 15, 2019 Death wobble is a very complicated thing. no single thing always causes it, and no single fix always cures it. Link to comment Share on other sites More sharing options...
Andy in Pa Posted December 16, 2019 Share Posted December 16, 2019 7 hours ago, Pete M said: Death wobble is a very complicated thing. no single thing always causes it, and no single fix always cures it. x2 for sure... Its usually slight looseness in a few different components, and can be combined with alignment problems, and even tire pressure too. Link to comment Share on other sites More sharing options...
WahooSteeler Posted December 19, 2019 Author Share Posted December 19, 2019 For now, the culprit apparently was a loose lower shock mount on the front axle. Time will tell, but I'm not sure if that didn't come loose because of the DW. Shop said that was the only thing they found loose. The tech drove it, the shop owner drove it and I drove it and no DW. I'm gonna take a closer look at the trackbar mounts and see if the mounting holes have worn themselves larger and put a torque wrench on everything again in about 3-4 weeks. Link to comment Share on other sites More sharing options...
75sv1 Posted December 19, 2019 Share Posted December 19, 2019 On 12/15/2019 at 1:03 PM, Pete M said: *could* would be a better word. I've driven on a few bad/loose trackbars and have never experienced DW. I've driven with the track bar detached. On smooth roads it was like a rudder on a boat. I could do 55 mph. If I hit a pot hole or something, not good. Long story on that trip. Link to comment Share on other sites More sharing options...
Andy in Pa Posted December 19, 2019 Share Posted December 19, 2019 2 hours ago, 75sv1 said: I've driven with the track bar detached. On smooth roads it was like a rudder on a boat. I could do 55 mph. If I hit a pot hole or something, not good. Long story on that trip. Wow, I couldn't even back mine out of the garage with a 3" lift and no track bar. I would have drilled and mounted up a damn broom handle before trying to drive with no track bar. ANYTHING is better than nothing in that case. Link to comment Share on other sites More sharing options...
75sv1 Posted December 19, 2019 Share Posted December 19, 2019 2 hours ago, Andy in Pa said: Wow, I couldn't even back mine out of the garage with a 3" lift and no track bar. I would have drilled and mounted up a damn broom handle before trying to drive with no track bar. ANYTHING is better than nothing in that case. mines 4.5" lift. And no I do not recommend driving without a track attached. Its basically, Russian Roulette. It was a Sunday and I was far from home. I did get to an exit and had it welded back on. That lasted and hour or so of driving. When they brake off, it gets interesting. I did roughly 20-30 mph down the side of the road. In some spots it was more like 10 mph. I parked it a week to get it welded back on. It actually, did well in the 15 mile drive. I took back roads as best I could. I think mine was a few items. First was a lose TRE. Taper was to big. Chevy 1-ton. The next is the frame was cracked a bit back from the gear box. Edit: I forgot to add that the upper control arms had the holes wallowed out. They were old style Rust's, and used. 1/16 sheet metal. I replaced upper and lower with JKS. I bought some CORE uppers to replace the Rusty's upper as I have a few other XJs to build. Also, my Trac bar is a Rusty's OTK. I do not see anything wrong with it. I did buy an OTK Ironman 4X4 tracbar, etc. See how that goes. Link to comment Share on other sites More sharing options...
Andy in Pa Posted December 19, 2019 Share Posted December 19, 2019 8 minutes ago, 75sv1 said: mines 4.5" lift. And no I do not recommend driving without a track attached. Its basically, Russian Roulette. It was a Sunday and I was far from home. I did get to an exit and had it welded back on. That lasted and hour or so of driving. When they brake off, it gets interesting. I did roughly 20-30 mph down the side of the road. In some spots it was more like 10 mph. I parked it a week to get it welded back on. It actually, did well in the 15 mile drive. I took back roads as best I could. I think mine was a few items. First was a lose TRE. Taper was to big. Chevy 1-ton. The next is the frame was cracked a bit back from the gear box. No worries, I get it. I have had some sketchy rides home as well. Have made "track bars" from crossing ratchet straps under the front end just to get some XJ's /MJ's out of the woods and on the trailer. Trail repairs bring out all kinds of ingenuity sometimes. Link to comment Share on other sites More sharing options...
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