Death wobble is both an issue and a misnomer. It is a condition caused by worn front end components on vehicles with sold axles. Death wobble is terrible to experience but can be avoided with quality parts, maintenance, and a little bit of knowledge.
I could spend a bunch of time trying to write what “Death Wobble” is. It’s far easier to show you. Check out the video below.
Now that you have witnessed what “Death Wobble” is let’s talk about “Why” it is.
There are multiple pieces that all tie together to keep everything tracking straight and true. When any one of these is off it shifts the workload to the other components. What happens over time is the next part fails and then the next because each failure compounds the work of the next part in line.
What are those parts we keep talking about? It starts with the steering box. Mounted to the frame rail it interpolates the rotation of the steering wheel through an output shaft that turns the Pitman arm. (Don’t worry we have pictures!) The Pitman arm moves the drag link. This is an adjustable length rod that runs from the Pitman arm to the steering knuckle on the passenger side of the vehicle. That adjustment is used to center the steering wheel.
The tie rod is attached to the steering knuckle and runs the entire width of the vehicle and attaches to the opposite side as well. On the Jeep we used for this article there is an adjuster on the drivers side to set the toe of the vehicle. Toe is whether the tires are pointed towards or away from each other in the front.
So how do you diagnose “Death Wobble?”
First you need someone to help you. Unless you are Mr. Fantastic your arms are not long enough to move the steering wheel and check the suspension at the same time. You need to check the steering while the vehicle is on the ground, there must be tension on the parts or the movement won’t show up that we are looking for. Before going any further make sure to torque all of the bolts to the proper torque setting. Loose parts will cause a wobble just as much as failed parts and it is hard to differentiate if they aren’t installed properly.
With the vehicle running have your buddy cycle the steering from side to side while you are under the front end. Starting at the Pitman arm use your fingertips to feel each joint. Be careful to keep your fingers out of pinch points and away from sharp areas. It does take any pressure to do this just contact. The stronger a jolt you feel the closer you are to the issue.
Normal operation of any of the joints is side to side movement. They have to have that to allow the suspension to artuclate and rotate. What you don’t want to see is an up and down movement at the joint. Don’t stop just because you find one fault. Go from the Pitman arm all the way to the end of the last tie rod and annotate any parts that have failed. If you get vertical movement you know that these parts need replaced. To check the ball joints you can lift the vehicle in the air. Grab the wheel by the top and bottom and try to wiggle the wheel. If you feel movement or see any movement in the ball joints they need replaced. You will be able to tell pretty easily as they often times will also make a thumping noise when worn as they move around in the socket. This is best done with the help of a friend who can look at the joints and make sure it’s not a loose hub. (Thanks Rick for the input!)
Another item not mentioned above is the track bar. This should move up and down as the suspension moves but not have any sloppiness at the joints. Look for worn or cracked bushings and any other obvious signs of wear. If you torques the bolts earlier and these were loose it’s worth looking at the mount brackets. Take the bolts all the way out and check for any elongation of the holes. If they are oval shaped this was loose enough to move. You can get these repaired and install a larger bolt to take up some of the excess room getting you back on the road safely.
What if none of this works?
Well so far we have spent $0 to try and diagnose a wobble. If you follow the above steps and find nothing wrong it could very well be your tires. They could have a bad belt, be poorly worn or simply out of balance. The larger the tire the more these conditions are likely to occur and to be magnified through the steering wheel. One of our brand new tires had a flat spot and were terribly balanced. At 50MPH the front wobbled but would go away at higehr speed. I ran through the above checks, determined it was tires and took them to a professinal shop. One replacement tire and balancing later it rides perfectly.
How do you protect against it?
Once everything is ship shape again there are some things you can do to prevent the issue from returning. Maintenance is paramount, lubricate the joints that need lubrication, check the torque settings when you change the oil. Keeping those components tight is one of the best preventors to premature wear. We also recommend spraying the suspension with a good silicone spray to help prevent rust and dirt from sticking.
There are some aftermarket solutions that help strentgthen the steering system and allow it to handle larger tires, taller suspension, and heavier loads as well. In the next article we will look at the installation of the Synergy Suspension sector shaft brace and track bar.