Finally my heep is mving down the road under its own power but.. When i hit about 20-30 mph and hit a couple bumps my front axle will bounce and shake all over until i hit the brakes and come to almost a complete stop. and it feels alot like the death wobble i've seen in cherokees, but i think it seems worse cause my tires stick out so far i can see them bounce and shake where with a XJ you just feel it.
I thought it was cause i didn't have shocks but then i put shocks on and it still happened, so far i've put on shocks, balanced the tires and did a alignment on it. The TRE's are all new. Now i'm thinking the bushings in the 15 year old waggy springs i have could be the problem but i can't find poly ones to replace them with and i noone has stock rubber ones in stock. I guess i'll order so rubber ones if noone knows where it get poly ones.
I guess the Questions are
where can i get poly waggy bushings, or thier P#'s
And does anyone have any ideas on what could cause this wobble. Its on a 89 YJ with 3/4 ton fullwidth axles with all new outers.
thanks for any help

Hey, I know what your going through. I have a 94 YJ with fullsize 3/4 axles also and I get that same wobble. Only happens after hitting bumps, I think mine is mainly caused because I have no steering damper on yet, but when I was crawling around underneath I noticed that the bolt that holds the drag link to the knuckle had come loose and the cottor pin was keeping it on, so I tightened it up and torqued my other bolts down and greased up things and the problem got better.....might just check to make sure your tight on the bolts:smokin:

what steering stabalizer and how man are you running on what size tire???? i would also replace the bushing because it is about time for that but the steering stabalizer should be the first thing that you consider, the dampeners seems to be the root to all of the death wooble probs

Just to chime in. I run HP60/14bolt full width with 44044s (rancho waggy lift springs) and have absolutely no "wobble". I also do not have a steering stabilizer and run 38's. I don't think worn bushings would cause that severe of a wobble, perhaps the springs are totally shot. Poly bushings might help and are no doubt a good replacement for old rubber bushings, but are your rubber bushings that wallowed out?

If they are ovaled out then I think it could contribute, but watch your springs when you get the "wobble". What is your draglink angle (steep, 5-10 degrees, or what)? High-steer? What's your caster? All these could contribute to a wobble also. Good luck with it.

My Yj did this exact thing when the axle ubolts in the front were loose. A buddies does it when the shackle bolts are loose.

David

if the angle on your drag link is high it will make your tie rod twist, this will give you alot of play in the steering. It will do this even if you have new tie rod end's. Have some one look to see if your tie rod is rotating while you turn.

i just tried a search on "death wobble" and there was a few threads that you might want to look at.

I'm running 35 15.5 SX's on full width 3/4 ton dodge axles. 44/60. I have the drag link above the springs and the tie rod below. ( simple crossover) The drag link is almost horizontal to the ground. Not running any stabilizers and i'm pretty sure the spring are fine. they are the 6 leaf packs and have some pretty good arch to them still. I tighten up tha shackle bolts and that seemed to help but it still did it a couple times. the bushings arn't wallowed out at all just real soft from age. I couldn't find the bushings at autozone or advanced and the dealer wants 25 a piece for main eye bushings so i am going to try and find some poly ones for it. Castor is stock for a 70's 3/5 dodge and i've only used 3 degree shims so far so i don't think the castor is bad.
thanks for the ideas fellas

I got YJ poly bushings, but you'll have to get extras.

The large bushing at the frame end of the YJ spring is used on both ends of the waggy spring (at least on the 44044s I have) So if the bushings are the same size (I'm just not sure on stock waggy's so check) then you can use the large YJ bushing in each end. Basically it'll take 1 energy suspension kit to get 2 large bushings and 4 small bushings. You only need one small bushing for the frame (unless you've already changed those).

I only needed 1 kit because I got poly's with the 44044s and just replaced the frame bushings. I'm not sure if you can purchase these bushings individually but it sounds like that would help. Just call up someone who deals Energy suspension an check.

It sounds like you've covered all your bases otherwise. Just out of curiosity did you find out what stock caster was for a 70's 3/4 ton dodge? I was just thinking that if it was less than 3 degrees (which I doubt) and you added 3 degree shims it might produce some funky handling. Have you run in 2wd without the shims just to check? might just give you piece of mind.

The stock waggys have a large bushing at one end and a smaller one at the other. I will check on if a YJ bushing would work in the big end and on the small i used small YJ shackle bushings but had to trim a little off the edges to get it to fit in the stock hangers. I drove it in 2wd with and without the shims in and it still did it. For some reason it isn't doing it as much now, maybe tightening the shackle bolts helped. It still does it sometimes. i am going to order some poly bushings and see if that cures it. now its time to figure out why my engine is ticking. thanks

Have you checked toe in?;)

yes, that was the first thing i checked

I have the same problem, and have gone through a LOT of research and testing, and have concluded that mine is caused by too MUCH castor.

A lot of research yielded the information that most long time builders like LESS castor as tire size goes up to reduce/eliminate death wobble. This goes contrary to what you might think, but this is from experienced guys who've done it.

In my case, I ADDED castor when I did my shackle reversal (springs lower in the back), and when I did my cross over (had to tip back the axle so that there was no interference between the drag link and the springs). Either one of these things alone would not cause a problem, I know because at various times I've had one or the other. But added together they add up to a lot of castor which causes the problem.

I am currently building a new steering arm with more lift on it which will allow me to rotate the axle back to a castor which is more preferable, which I hear is around 3 ~ 5 degrees. Currently I am sitting at 10 ~ 14 degrees of castor.

I am not saying this is your problem, because the frustrating thing about DW is that there are so many things that can cause it it can be difficult to trace, and it's often caused by a combination of things.

Some other things I've found:

While the amount of castor in my setup creates the PROPENSITY for death wobble, I still need an event to set it off (ie: hitting a bump with one tire), as well as some play in the components. I found that making sure everything is TIGHT can really cut down on the DW, as well as the severity of it when it does happen. This is very important. After doing this, it didn't really change the 'feel' - I still got the feeling it was going to DW at a certain speed at any time - but often it didn't actually happen any more,and when it did, it was less severe.

The other thing that made a BIG difference was switching tires. I run 35 X 15.5 swampers. These things are notoriously out of round and unbalanced, and I found that between these two facts and the flat spotting, the swamper vibration ALONE was enough to set off a DW - I didn't need to hit any bumps of anything, the bumpiness of the tires set it off! Now I'm not giving up my swampers, so what I did was get a set of cheap ATs to run as street tires for those few occasions when I HAD to use the rig as a DD, which happens very infrequently. My point is that a good set of ROUND, BALANCED tires will make a huge difference. The propensity to DW is still there, but it rarely happens with the street tires.

The other thing I really found was the flat spotting. This of course causes major tire vibration, which can in itself induce the DW. What I found was that if I drove the rig after it had been sitting on the tires and they flat spotted, it would almost certainly DW. If I drove the rig immediately after mounting them, so they were not flat spotted, the tire vibration was reduced by like 2/3, and therefore they did not DW nearly as much. This is where having another set of tires comes into play again - because I have 2 sets, I typically mount my swampers just before going wheeling, and so I avoid the DW before I am happily and safely on the hwy at > 30 mph on my way to my trail.

Anyway, check your castor and I hope some of this helps.

Chad

Chad that's some good tech:beer:

This thread will definitely be good for the newbie searching on DW from now on