Death Wobble is not always the track bar

I have some interesteing pictures from my recent work on the Daily Driver I am making. I have been battling some major DW that happens around 45-55 MPH but will go away at highway speeds. It is sparatic, and it usually happens after hitting a bump or some other unsettling of the suspension.

I am in the process of replacing my rear springs and front control arms, adding alot of Poly bushings along the way. I took a set of 4x4 MJ springs and Rehab'd them by tearing them down and painting them ala Mjeff87 with some EZ slide paint. I also added Poly bushings when I put them back together with my Rusty's AAL. I am replacing my control arms with Stock, that have rubber and poly bushings. On the Uppers I have the poly on the body side and the rubber in the axle. On the lowers it is the opposite. Poly at the axle end andurbber on the body side. This is where the focus of the story is. I presssed out the bushing on the passenger side after I had done the LCA swaps. When I compared it to the new one I was amazed at what I saw. The hole had grown by an 1/10 of an inch. That is alot of slop for suspension stuff.

Old one is on the left. Can you tell why I am amazed?

Old one Mic'd

New one Mic'd

I am not finished with the swap because I learned a very hard lesson today. When doing the control arms, it is alot easier to do when you unhook the shocks, swaybar, compress/remove the spring, and do the uppers first, then the lowers.

I will finish and report the ride quality in a few days. I hope to have new rear shocks on by then as well. The final touches will include new swaybar links from a TJ(about 2 inches longer), a new steering stabilizer, and rebuilding the trackbar with poly. All these things should make it a great daily driver.

my death wobble was fixed by LCA's

i have bad dw at 40 to 50, but you can feel it shaking at times when you first start off driving for that day. when in 2nd gear (i have an auto), it doesn't shake at all, not even at lower speeds.

i am not going to be throwing a lot of money at every issue this could be, because unfortunately, i don't have any money. so one of my dads buddies that he works with has a brother who is a mechanic. and he is going to take a look at it during the second week of march. he's over half way across the states right now i believe. but i have been told he knows the mjs like the back of his hand.

and actually you can have a loose track-bar with NO death wobble or any indication what-so-ever.

i was driving tonight, went into a slight corner at about 45-50 (the speed limit) and the truck iddn't turn so i cranked the wheel about far enough to make a 90* turn and barely scraped by without knockin the truck next to me.

pulled over as soon as i could and found my track-bar lying on the diff, and the castlenut chillin in the frame mount. :eek: :eek: :eek:

re-installed and cranked down as much as i could. but there was no prior indication of the problem, and it had ot have been loose for a while considering it fell out on its own. but i was doing 70 about 10 miles prior to this no problems, smooth as glass, hten the whole way home from work before that 45-60 smooth as glass.

While one bushings hole is larger that the other, really all you found is manufacturing differences.

If you look close at the old/larger holed bushing. You will see little "tits" on the inside. These are what the bolt rides on and these are what, in effect, creates the diameter of the hole. The new bushing is merely a piece of steel rolled making the same diameter hole as the "tits" make.

Don't read me wrongly, I am not saying that the old one isn't worn. It is, just look at the rubber. All I am saying is that the differences are not nearly as much as they first appear.

Also, a word of advice, if your building a daily driver, the poly may prove a bit harsh and will in-fact actually impede articulation. By not compressing as much or as easily as the factory rubber bushings will. As to the harshness, while it does isolate some of the bumps it will transmit more into the passengers than the factory rubber bushings do.

Good luck and good building!!

CW

While one bushings hole is larger that the other, really all you found is manufacturing differences.

 

If you look close at the old/larger holed bushing. You will see little "tits" on the inside. These are what the bolt rides on and these are what, in effect, creates the diameter of the hole. The new bushing is merely a piece of steel rolled making the same diameter hole as the "tits" make.

 

Don't read me wrongly, I am not saying that the old one isn't worn. It is, just look at the rubber. All I am saying is that the differences are not nearly as much as they first appear.

 

Also, a word of advice, if your building a daily driver, the poly may prove a bit harsh and will in-fact actually impede articulation. By not compressing as much or as easily as the factory rubber bushings will. As to the harshness, while it does isolate some of the bumps it will transmit more into the passengers than the factory rubber bushings do.

 

Good luck and good building!!

 

CW

This is my reason for keeping the front Control arms half poly and half rubber. My hope is that the rubber will add just enough drivability to make it tolerable. Also the plans for this truck are to complete a total Reso-Mod over the next 3-4 years as it is going to be my sons truck when he gets his license. I will have to look at the old bushing. I did not notice the inside. Thanks for the heads up.