Death Wobble

[Gunnibronco]

So yesterday my truck went into "Death Wobble" 3 times. The first two times, I was traveling about 25mph on a poor quality paved road. It would start while rounding a bend on bumpy pavement. The last time was about 45mph on a highway, but the right wheel hit a dip in the pavement.

I have looked things over and see a few problems.

First the frame is cracking, and flexing badly around the steering gear mounting points- typical. Time to plate the frame and probably do the 4x4x2 box.

Second, the passenger side radius arm is just slightly loose in the hanger. The heim misalignment (really just pieces of pipe, supplied with my arms) has a bit of slop against the bracket. Like the bracket has opened up slightly. I think this is caused by the wobble, not the original cause of the wobble. The drive side is tight.

P1020251.JPG

Finally, when turning the steering, the tie rods rotate A LOT. I've attached a video here, its most obvious starting about 25 seconds into the video:
https://www.youtube.com/watch?v=YwYc16w ... e=youtu.be


The TRE & DOM was installed when I went full width in March 2011. New high end Moog ball joints, wheel bearings, etc then too. I reamed the pitman arm for the drag link down through to get a better draglink/track bar alignment. The TREs and drag link ends chewed up and out a couple of the rubber dust boots pretty quickly. I always wondered why. I'll probably switch to a stock pitman arm when I swap the steering box, so that might not be an issue soon.

Thoughts, ideas, glaring problems?

[Justin]

Yes to all of the above. My tie rod ends were about that bad when I did the 1.5" tube upgrade and new ones made a significant difference in how the rig drove. I'd put proper misalignment spacers in the heims if you don't have them already (I can't remember which arms you're running-Battlement?). Probably the biggest safety issue is the frame repair.

[Gunnibronco]

Thanks,

Although I can't find my receipts, based on current prices, I'm pretty sure I bought the "premium" TRE's from Carquest when I did my C***y/DOM steering. I just thought they should have lasted longer than 3 years. Any ideas on why they have failed so quickly? I know I drive my truck a lot & a fair amount of off road, but just 3 years?

[Gunnibronco]

I found a picture from my axle swap thread, looks like I have the Pro grade Raybestos TREs. They only have a 24 month warranty, Moog has a lifetime warranty. Guess I'll get the Moog this time.

[ZOSO]

It's just the design of the system. Moog's will wear out too. Only way to get rid of it and the slop in that style steering is find a tre where the draglink will mount on top. Or get hi steer arms and run the drag link to the arm and off the tre. With the angle of the drag link on a downward slope its pushing "down" and pulling "up" with each turn of the steering. Thats where the roll comes from.

[landshark]

I have always fought this as well chad. No matter how tight (or new) my tre's are after a few weeks they start to flop from the angles. What I have found that has helped for a while is to retighten both ends of the tres at the knuckle angling it back to help the draglink push and pull more " flat". If that makes sense. I plan on going histeer one day but right now drives pretty well.

[Gunnibronco]

Cool, thanks for the advice. I'll just add new TREs to "to do" list.

Looks like I'll be swapping to the 4x4x2 box (rebuild & drill & tap for hydro assist), new TREs, and maybe new brackets & high misalignments for my radius arm rod ends. I'll be cutting off my upper spring buckets & installing the adjustable, full width buckets and pushing the axle forward 1" or 2".

[Digger]

2x on everything said already. The only way to get away from the wear issue on the TREs is to get the drag link level so there is not a vertical component to the forces on the tie rod link. OR come up with an anti-rotation feature on the tie rod link.

I have had limited success with tightening the TREs on the tie rod with one rotated forward and the other backwards such that the tie rod cannot rotate.

In you video, there looks to be some lateral motion between the axle housing and the frame. How are your track-bar bushings? Bad bushings would be a major contributor to death wobble.

[Gunnibronco]

Thanks,

I'll look at my track bar when I pull things apart. On the frame end, it is a Ruff Stuff rod end, intstalled at the same time as the TREs, axles, radius arms. The axle end still has the poly bushing that came with my lift kit. Its only been installed since 1996 so it couldn't possibly be bad, right? LOL. It didn't look bad when I swapped axles 3 years ago.

[Digger]

Check the rod end because any play is bad. It would allow the body to freely float back and forth and when it closes the gap, will act like a very high rate spring. (Think about a ping pong or golf ball bouncing rapidly between two hard surfaces.)

[Gunnibronco]

I went to Carquest today and asked about the warranty on their TREs. It is a "lifetime" warranty so they will swap my bad ones out.

On Rockauto, they list Raybestos as a 2 year warranty. Carquest is selling the same Raybestos stuff with lifetime warranty.

[Gunnibronco]

I've got everything apart. The track bar rod end seems tight, but the jam nut was not tight.

The sloppy tie rod ends, flexible/cracked frame, and the loose track bar end I'm sure all added up to the wobble.

I'm replacing the heim joint on the track bar, high misalignment spacers to the radius arm ends, and replacing the tie rod ends & drag link ends.

[Jesus_man]

That is indeed the trouble with DW, it's usually a factor of many components. I've also found it easier to spot the slop in the steering with the engine off and just steering the wheel until it's too hard to do with one hand and back again. It helps a lot to have a partner steer for you, while you crawl under it and look at the system from one end (steer box at the frame) to the other (knuckles).

[Gunnibronco]

The only way to get away from the wear issue on the TREs is to get the drag link level so there is not a vertical component to the forces on the tie rod link. OR come up with an anti-rotation feature on the tie rod link.

Just saw Ruffstuff came out with these.

Camera Download All Photos until 10-31-14 1279.jpg

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http://www.ruffstuffspecialties.com/catalog/R1768.html

What do you all think? From their description, this should stop the tie rod from rolling, due to the vertical push from the drag link.

[Justin]

Interesting. I could see it help on end with some wear.

[Dirtheadz]

Just saw Ruffstuff came out with these.

Camera Download All Photos until 10-31-14 1279.jpg

FULL019.jpg

http://www.ruffstuffspecialties.com/catalog/R1768.html




These are popular with the desert racing crowd, typically used on twin I beam, swing set steering. People used to make them out of regular poly spring bushings. Keeps heims from flop'n

[landshark]

ha i was just looking at those.. pretty interesting might pick up a few to test out

[Gunnibronco]

ha i was just looking at those.. pretty interesting might pick up a few to test out

So it seems these just go on the drag link/tie rod connection, not on each tie rod end. Right?