How do I identify if my Jimny really has a death wobble?

Why does my Jimny have this potential problem?

The Jimny has a live axle and ladder chassis set-up, which is ideal for four-wheel driving but is a compromise for on-road comfort. In extreme cases, the King Pin / Shim preload is the main cause of the death wobble, and if the kingpin bearing preload is not correct and cannot be set correctly, new shims need to be fitted and torqued correctly (to correct preload) to resolve this problem. Worst case scenario, complete new King Pin bearings, and shims need to be fitted to rectify this phenomenon. Many live axle and ladder chassis vehicles have a death wobble speed range. With the Jimny it is between 60 to 80km/h.

If your Jimny has done in excess of 100,000 kilometres without having King Pin Bearings replaced or a lot of off-road work there is a strong possibility that your King Pin Bearings will need replacing.

Please Note: Death Wobble and Body Sway are two entirely different phenomenon. Death Wobble is when you feel as if you are losing control of your vehicle with excessive and uncontrollable vibration felt through the steering wheel. Body Sway (Gen 4 specific) is when the vehicle body sways / rocks from side to side gaining momentum uncontrollably with no vibration being felt through the steering wheel (suspension related).

What can I do to check if my kingpin bearings are a problem?

Checking if to see your Kingpin Bearings are worn is quite a procedure. This requires removing the front wheels and hubs, disconnecting the tie rod ends so that the steering knuckle moves freely, removing the side shaft and CV, then load testing the steering knuckle to check for the correct tension. At this point, given the time and cost of this exercise, one might as well replace the king pin bearings, seals and shim the kingpins at the same time.

In many cases, your king pin bearings and shim preload settings maybe 100%. In order to rule out performing the above costly exercise, below is a list of what you can do in order of cost priority before looking at / checking and replacing your Kingpin Bearings:

Please Note: Worn or damaged Castor Correction Bushes have absolutely no impact on creating a Death Wobble. The rubber bushings literally have to be completely separated from the inner or outer steel housing before impacting on, or adding to the Death Wobble.

Worn Castor Correction Bushes will only contribute to / create Bump steer or roll steer on a vehicle, which is the tendency of the wheel of a car to steer itself as it moves through the suspension stroke. Please see our FAQ document here for more details on Castor Correction Bushes.

Check your tyres thoroughly

Des Sol is finding that more and more customers are having problems with Death Wobble even with brand new tyres. Tyre problems seem to be a growing issue not just with worn tyres but also new tyres. We seem to be receiving a growing number of sub standard tyres in South Africa and Des Sol have had issues with “out of round” or “defective” new tyres that have contributed to Death Wobble problems. This is not brand specific. Defective tyres will result in both Death Wobble issues and vibration when travelling over 100km/hr.

• A quick give away is the amount of weights used to balance these tyres. The Jimny tyre’s should not have more than 90g’s of balancing weights in total on one tyre. If there is more than this, the fitment centre need to first rotate the tyres on the rim (normally 180° then 90°) and rebalance. This used to be a standard procedure but doesn’t seem to be followed that often anymore. If this does not rectify the balancing issue then the tyre is defective and MUST be replaced.
• Check your tyre pressures. The Jimny performs best at an on-road tyre pressure of between 1.6 -1.8 Bar tyre dependant on tyre size and side wall thickness, the thicker the wall the less pressure required. All tyres need to be at the same pressure, obvious but sometimes overlooked.
• If you have recently been off road in muddy clay conditions you might have mud stuck inside your rims.
• Get your tyres balanced. Make sure that your tyres are balanced using a stud balancer and not a spigot balancer. When your tyres have been balanced make sure that the wheel nuts are re-tightened while the vehicle is off the ground ensuring perfect central location.
• Check your tyres for wear / flat spots by spinning and monitoring the outer circumference of your tyre against a fixed point.
• If you have recently put new higher spec tyres on such as 205/75R15 or 215/75R15 for the GEN3 and 215/80R15, 225/75R15 and 235/75R15 for the GEN4 and they are muddies expect a small amount of wheel wobble occasionally but make sure you rotate your tyres regularly as the wear pattern on these tyres is not uniform.

Check your Steering components

An additional careful check of the following components before looking in detail at your Kingpin Bearings will potentially save a lot of time, money and frustration.

• Drag Link/Tie Rod Ends – Check the steering arm and trailing arm to make sure the adjuster bolts are tight, this is very uncommon but there have been occasions where wheel alignment centres have forgotten to tighten these bolts resulting in damaged arms and tie-rod ends.
• Steering Box Play – Excessive play in the steering box will emulate Death Wobble symptoms. The tension on the steering box needs to be increased, a quick easy fix.
• Suspension Bushings – Check for deterioration and play.
• Front Panhard Bar and bushings – If these are worn this will emulate King Pin Bearing failure problems.

What is a panhard bar?

A Panhard rod (also called Panhard bar, track bar, or track rod) is a suspension link that provides lateral location of the axle. Originally invented by the Panhard automobile company of France in the early twentieth century, this device has been widely used ever since. Click on the image below to see the full video of how the Panhard Bar works.

 

Please note that fitting larger tyres like 215/75 (Gen3 Jimny) or 235/75 (Gen4 Jimny) especially if muddies, expect a small amount of wheel wobble occasionally. To completely resolve this problem we recommend fitting our Des-Sol Steering Dampers.

Difference Between Jimny Models

The Gen 3 Jimny (JB43) is most prone to Death Wobble type issues for a number of reasons, mainly:

• The Gen 3 Jimny does not have an OEM Steering Damper fitted. A steering Damper goes a long way in absorbing wear during harsh on and off road driving conditions

Please Note: a Steering Damper should not be fitted after a steering wobble is apparent as this just masks the wear problem. A steering Damper should ideally be fitted only when the vehicle is operating at peak stability / performance as it will then extend the life of your steering components compared to when one is not fitted.

• The Gen 3 Panhard Bar Bushings tend to give problems early on in the vehicles lifespan and the bushing design has since been improved. This has been rectified on the Gen 4 (JB74) design where rubber bushing material and Pin OD have been modified.
• The GEN4 chassis is also significantly more rigid than the GEN3 chassis. As a result the Panhard Bars have larger bushing pin diameters and reduced bushing rubber content to minimize the build up of play which exacerbates Death Wobble.
• Des Sol have improved even further on this design with their High Strength Adjustable Panhard Bars for both the Gen 3 and Gen4 models. The bushings have been manufactured using ±40-50% less rubber bushing material and have a 20% larger pin OD. This has had a very noticeable and positive effect, reducing the incidence of Death Wobble problems over time and prolonging the steering components life span.