Things to look for before you modify your 4WD.
When it comes to getting the best out of your 4WD the idea of modifying the vehicle comes to mind. Especially when you need it to perform its best in rough terrain. At Indrotech we have found through our 20 years of dealing with 4×4 driveshafts that when raising your vehicle things can go wrong. Whether it be a Nissan Patrol a Toyota Hilux or any other popular 4WD people will always modify it to suit their needs; be it rock climbing, 4 wheel diving or just “bush-bashing”. But before you start we just wanted to give you a few hints on what to look out for to give you the best chance of it doing it right.
1. What the Manufacturer intended
First of all, you must remember that the original manufacturer made the vehicle to perform at its best in its current state. There is a geometry associated with the vehicle that is specifically designed to keep all moving mechanical components work in harmony. Altering this state will change these settings and therefore the dynamics of the vehicle.
So we have come up with 4 things to look out for when deciding to modify your vehicle.
2. Raising the vehicle
Once the chassis is further raised from the wheel base there is a significant change in the drivetrain. To explain, a universal joint angle is set to perform between 2-4°. If the vehicle is raised by 3″ or 75mm, as in the above drawing, this will increase the angle to 8°. This is over double the amount of the intended angle. The result of this would more than likely be catastrophic. The vehicle will severely vibrate and the universal joints will fail. That’s if the weld yokes that hold the universal joints don’t fail first. We also see in the drawing that the main prop shaft will need to be extended and rebalanced. The double cardan shaft, being a shorter shaft than the prop, will also need to be altered to accommodate the massive angle increase. You will need to talk to us about that…
3. The ride will change.
As a consequence of this alteration, you won’t only experience a horrible vibration; you will also feel that you’re riding in a boat. This is because the Centre of Gravity (C of G) has been horizontally offset by the amount the vehicle has been raised. In this example it sits 75mm higher. Therefore you will notice a more pronounced sway when you take a corner. You will also experience odd behaviour when you hit potholes. This is a suspension issue of which other specialists can solve.
4. There are experts that can help you.
Acknowledging what obstacles will arise if going down this path, please consider talking to industry professionals before you “open a can of worms” It truly disappoints me seeing young enthusiast spending lots of money only to find they have been lead down the wrong path. This can be a very expensive mistake that can be avoided if you speak to the professionals.
Remember we can all do our own handiwork with our 4X4’s but was this what the manufacturer intended. To avoid any issues or bumpy rides there is always someone to help you get the right advice.