Death wobble with smaller tires?

[JohnQ]

Due to all the accidents my family has had since April 18th, I am now driving my Comanche daily. I have a 62 mile round trip and I decided to swap my 245/75/16 MTR's for my set of 235/70/16 Bridgestone Revo's to save on some gas. Both sets of tires are on Rubicon Moabs. I had three episodes of Death wobble this morning on my way to work. My truck has a rough country 3 inch lift and some 2.5" spacers in the front.

 

Is there anything I can do to stop the wobble and keep the smaller tires on?

 

Does it make any sense that my truck has death wobble with the smaller tires or is it time to fix my front axle?

[mvusse]

If it didn't occur with the larger tires, I'd have the smaller ones rebalanced. If they are not the same rims, check to make sure they have no dents. Or put your rear tires on the front see if the problem persists. It may just be the different weight (and inertia) of the smaller tires creates just the right harmonic frequency with your suspension and steering system to start oscillating.

 

The smaller tires may or may not save you gas.They are narrower, so less roling resistance, and smaller diameter, so you're lower to the ground, but they also turn faster covering the same distance, making the engine rev faster for the same speed.

 

When you switch tire sizes, do not go by the odometer for distance or speedometer for speed. Use a GPS instead, or a trip of a known length. If you're speedometer/odometer assembly is correct for the one tire size, it will be off for the other size. You may think you saved gas because you're odometer says you drove 120 miles while in fact you may have only driven 114.

 

The two tire sizes are almost exactly 5% off from each other.

[Eagle]

Why are you running spacers on the front? You shouldn't need them with those smaller tires. Try driving without them. Elimnate another variable.

 

And +1 on having the tires balanced.

[brigarpeon]

I would say what has happened in your case is the largest tire weight nodules and largest wheel weight nodules are aligned around the concentrical center. Heavy side tire and heavy side wheel are both on the same side of the assembled wheel and tire in relation to the center. It could be only one of the front tires.

 

Take them to a shop that has electronic spin balancing with a kinetic read out and use the adhesive weights. That will tell you how much weight is off to one side. Break that tire and rotate it 180 on the rim. Then have them balance as close as they can with as little weight as possible. Doing both fronts will guarentee wheel balance.

 

The truck did not do it before the tire change so in this case the balance is the most proable cause of Death Wobble.

[DrThunder]

Don't want to be a wise guy but 5.5" of lift on short arms can be the culprit. Take the spacers out, you don't need that much lift ever imo.

[camo89]

there are maney things that can cause deth wobble

 

but if this dident start till after tire swap

 

the rubber is the problem

 

rotoat see if it gose away

rebalance

[JohnQ]

Well I went to a shop today and had the tires all balanced and rotated again. Had all my bushings and ball joints checked. Nothing is loose, but I still get the wobble. And at 50-60mph it is pretty darn scary!

 

I have the spacers in the front because of the heavy @ss ARB bumper. My truck sits nice and level with them in. I'm going to switch my wheels back and see if I still get the stupid DW.

[Eagle]

My bad. I read the initial post quickly and I thought you were running wheel spacers, not spring spacers.

 

Gotta be tire balance if the other tires didn't do it. How much weight is on each front wheel, and how much is to the outside and how much to the inside?

 

I've said before and I'll say again -- just because you paid a shop to balance your tires does NOT mean that your tires are balanced. An awful lot of the so-called "technicians" running those machines don't really know anything, and they rely on the machine to do all the thinking. "Close enough" when you're dealing with a solid axle Jeep is usually NOT close enough.

[JohnQ]

No more death wobble! At least for now.

 

I'm pretty sure my stabalizer was shot and the whole steering set up was pretty loose. I robbed the whole steering set up from my 89 and put it on the 88. Everything is nice and tight now. I put almost 20 miles on her and no more DW so far.

 

I also get to keep my baby tires on for now! :D