Rose Joints & Bushes
Now don’t panic; this isn’t a recap of High School biology, nor are we looking to discuss peoples never regions. Instead this article will cover one of the most over looked chassis components that will dramatically affect the drivability and handling characteristics of your vehicle. No matter whether you wish to maintain OEM performance or look to build a monster of a track vehicle, the choice of bushes or hard fixed applications are critical.
For those still learning the ropes of being a spanner monkey or petrol head; the bushes are the very component found around both front and rear subframes, differential mounts, supporting traction arms and suspension components. On some applications, you can find bushes within the steering rack, anti-roll bars and drop links, as well. Ultimately the purpose of the bush, no matter the location, is the same; to provide an element of shock absorption as means of comfort and tolerance for parts to move under stressful conditions.
Rose Joints and Solid Bushes however, are used in place of bushes to ensure rigidity. By trading comfort for rigidity, the car will feel more solid, but also a lot more predicable and agile. Additional benefit can be found within the delivery of power to the wheels, with less slack (lash) within the mounts of the drivetrain (differential, etc), maximum power is delivered to the wheels. That said, if you drive the car like a hero or drift king without uprating the drivetrain or strengthening mods (covered in other articles), then this will begin to stress the chassis, causing more cracks than your granny’s face.
How Can I Tell If I Need to Upgrade?
- The car will drive in a nervous fashion, especially over uneven, rough surfaces
- Components will knock, clonk and bang
- The vehicle will surprise you with sporadic drifting from steering straight
- OEM bushes are cracked and crusty
- You’re the next Vin Diesel and you want overnight parts from japan to wipe the floor with other racers.
Enough Education, Tell Me What I Need…
You’ve got yourself a nice, sporty little number; The question is, what do you want from your vehicle?
Designed for road use, maximum comfort and drivability under normal conditions and OEM vehicle performance
Designed for fast road, to provide improvement to road handling and performance, with minimal impact to comfort.
Designed for fast road and track use; Handling performance is considerably improved, but comfort is sacrificed. Ideal for vehicles with enhanced performance over standard.
Designed primarily for track use; Optimum performance, minimal comfort. For extreme vehicle applications with uprated drivetrain and strengthened chassis components.
Rose Joints are solid joints that remove the requirement for bushes in the suspension/tracking arms.
The offer the same benefit as the solid bushes shown above, however solid bushes aren’t available for the suspension arms, instead rose joints are used.
The joint itself allows for adjustment as well as providing a stiffer form of shock absorption.
Parts In Hand, Let’s Do This
So you’ve got the parts, you’ve got a tool kit and your ready to hide in the garage away from your partner. Before you fit the parts, it’s good to understand the different bush designs and what tools are needed before turning your pride and joy into a mechanical jigsaw puzzle.
There are often two types of bushes, the solid state and two piece. The solid-state bushes are those that come in one piece, commonly OEM replacements and solid. Pending the brand, the majority of aftermarket bushes (Mild/Hard) come in two parts. The reason for a two part design is to make installation easy and something relatively straight forward; without the need for a hydraulic press, you can simply push each part into either side of the mount or arm. Single piece units will require a hydraulic press to remove the old unit and install the new; yes, this means you either need to pay a garage or get creative on the driveway.
Tips For Installation:
- Use plenty of grease when installing the bush; get the lube on and it’ll slip right in.
- When installing two piece bushes, ensure the metal bolt collar (tube) is installed. Without this, the bush will perform as good as not having the bush there at all.
- Check all bolts and fixings are to the correct NM torque settings.
If you install solid bushes and rose jointed control/traction arms, ensure regular ‘nut checks’ are conducted. This isn’t an act of fondling yourself, this is a safety critical action that needs to be conducted periodically or if the car is used on track/driven hard. It is good practice to get the car up in the air and check that nothing has worked loose from vibration, a side affect from having no absorption.
Once fitted, give the car a spin, feel like a driving hero. Enjoy!