Dos and Don'ts When Buying a Thrust Arm
The suspension system in your car consists of different bars linked together to keep the vehicle in one piece. It also connects the car's body and wheels so you can roll safely above the ground. An important component that allows the steering knuckle to move vertically is the thrust arm. It is often referred with different names, and even interchanged with different functions that might mislead and confuse you. Read this guide to help you clarify the things you should know about this part.
- Determine first if the thrust arm is the part that you really need. A thrust arm is a bar with a bent shape. It has a bushing holder on one end, and a ball joint at the other. Don't confuse it with a wishbone that's shaped like a wishbone, or a control arm that's just a straight bar. You can find the right description of the part to the thrust arm the installed in a BMW or a Mercedes Benz.
- Read the specifications when you are buying a new thrust arm. The details include the make, type, and year of a car. You should only purchase a thrust arm that's compatible to your car.
- Check if the thrust arm already includes a ball joint and a bushing. You can save your money if you choose to buy a complete set.
- Consider looking for a new rubber boot as well when planning to replace a thrust arm. Since you already purchasing a new thrust arm, it will be easier to install the thrust arm by dismantling the rubber boot in the process.
- DO NOT combine your old thrust arm bushing with the new thrust arm. This will only damage the new thrust arm, and it will only put your car at risk.
- DO NOT purchase a replacement thrust arm from an unknown brand or reseller. They will not be offering the same warranty that trusted names offer.
Vehicle Repair 101: Replacing a Thrust Arm
Your car's thrust arm helps you enjoy a smoother drive and easier handling. However, over time, it'll wear out. Good thing replacing it is a fairly mangeable process. If you need to replace a thrust arm on a BMW E34, read on.
Difficulty level: Moderate
- Floor jack
- Jack stands
- 22mm wrench
- Socket set
- Pickle fork
- Lug wrench
- New thrust arm
Step 1: Park your car on a level surface, and engage the parking brake.
Step 2: Jack up the vehicle, and secure a comfortable working height using the jack stands. Never use the floor jack to hold the vehicle's position. It has a tendency to slide down.
Step 3: Check on which side of the car is the thrust arm you need to replace. Remove the lug nuts using the lug wrench and the front wheel on that side.
Step 4: Use the 22mm wrench to remove the two nuts that hold the thrust arm at both ends.
Step 5: Take the pickle fork and remove the thrust arm's ball joint. If a pickle fork is unavailable, you may use a tie-rod puller. Be careful not to damage the thrust arm boot if you will not be replacing it.
Step 6: Remove the nuts and bolts that hold the thrust arm to the frame. Pull out the current thrust arm afterwards.
Step 7: Get the new thrust arm and mount it to its frame. Secure the thrust arm using the nuts. If the ball joint rotates while the nut is tightened, hold its position using the pliers.
Step 8: Re-install the lug nuts and the wheel in their previous position. Bring down your car by jacking it up again, and then by removing the jack stands below.
Step 9: Tighten the thrust arm bushing nut under load. It is better to use a ramp so you don't have to slide underneath.
- If you will replace your current thrust arm with a new one, then you should also replace the thrust arm bushings. It will be time-consuming to detach the parts again just for a bushing replacement.
- You may use a lubricant like WD 40 to remove the parts easier, and you can use it to clean as well.