Next to your engine and gearbox, maintaining your suspension is one of the best things you can do for your car. The suspension is both what keeps you connected to the road, and what absorbs all the road’s imperfections, and in a bad state of repair, it will hurt your fuel economy, decrease the lifespan of your tyres, and adversely affect your car’s ride and handling, not to mention make your car less safe to operate.
Thankfully, rebuilding a suspension on many cars is not a terribly expensive or exceedingly difficult undertaking, and doing so can make a tired old car feel much newer again. It is also a job that can quite often be done an average DIY-er.
The front suspension on my 2002 SEAT Leon Cupra has been in need of a refresh for a while, and last week I finally got around to tackling the job. This post details the process. As the Mk1 Leon sits on the Volkswagen Group A4 platform, I believe the process will be the same (or very similar) for a Mk4 VW Golf, Mk1 Audi A3 and TT, and Mk1 Škoda Octavia. I apologise in advance for the quality of some of the photos – I was working in the evening as light was fading.
Notice the setup of the Leon’s front suspension. A lower control arm mounts in two places to the subframe, and to the bottom of the hub with a ball joint. Connecting the steering rack to the hub is a tie rod, and an anti-roll bar link connects the bar to the lower control arm. On the whole, it’s quite a simple arrangement.
The first step is to get everything loose. Begin with the 18mm bolts connecting the control arm to the subframe.
Next, remove the anti-roll bar link by removing the 16mm fasteners.
Following this, remove the tie rod end from the hub. The 19mm nut may spin off, but more than likely, particularly if the ball joint is worn, it will spin the ball joint as well. In my case, it was necessary to remove the boot, and firmly fix a pair of vice grips on the ball joint shaft in order to remove the nut.
However, before you actually remove the tie rod end from the hub, you will want to loosen the lower ball joint nut. If you wait until you’ve removed the tie rod end, the hub will start to move, making it difficult to loosen the ball joint nut. Just back it off to the point where you can spin it by hand, as you won’t be able to fully remove it with the CV joint in place.
Next, remove the three 13mm lower ball joint mounting bolts from the lower control arm, and pry the control arm away from the ball joint mount. This is not a necessary step, but it makes it a bit easier to remove the control arm if the ball joint is no longer attached.
At this point, on the other side of the car, the ball joint simply dropped out, but on this side it required the use of a ball joint fork to extract it from the hub. You’re not going to be saving any of the pieces, so do whatever it takes to get that old ball joint out. I had to pound on this one quite a bit to break it free.
Once the ball joint is broken free, simply remove the lower control arm. In most cases, you should be able to do this by hand, but a few taps with your rubber mallet won’t hurt if you find it’s stuck in the subframe mounts. Then spin the ball joint nut off all the way and remove the ball joint.
You can see here that the bush is worn out and cracked. It’s not the worst I’ve seen, but new bushes will certainly help firm things up. Some people choose to keep the control arms and merely replace the bushes, which can be done, but the cost of buying a new control arm is so minimal, that in my opinion, it’s not worth the effort.
The final step in the disassembly process is to remove the inner tie rod from the steering rack. Removing the boot is one of the most difficult parts of this job, simply because of lack of space. I took a long, flathead screwdriver and eventually managed to pry the clip free, but you’ll need some patience here. Once it’s off, take a 34mm spanner to the tie rod, and it will spin off quite easily.
Now that everything is out of the way, you can begin to reassemble the front suspension. Begin with the inner tie rod, and screw the new piece into the steering rack. Once it’s hand tight, finish tightening it with the 34mm spanner. Don’t overdo it – once it is seated, just give it a turn with the spanner to set it firmly in place. Replace the tie rod boot, and then spin on the new tie rod end. Don’t attach it to the hub at this point.
Then you can set the new lower control arm in place. You will need to use a rubber mallet to tap it into the subframe mounts, but it will slide into place quite easily. Do not worry about aligning the holes perfectly just yet.
Push the new lower ball joint into the hub, and tighten the nut. The control arm I purchased already had the ball joint attached, but if yours doesn’t, make sure you fit the two pieces together before you place the assembly in the car. Interestingly, despite the fact it was easier to remove it separated, it’s much easier to refit it together.
Pay close attention to what kind of nut comes with your kit. Notice here that the new nut has a rubber ring inside of it, which is meant to act as a kind of lock. Normally, nuts like this fit onto a bolt with an opening at the end for a 5mm allen key, which holds it in place as you tighten the nut. However, it would be impossible to use this nut here, because as you can see, there is no room to use the allen key with the CV joint where it is. The result would be that the nut would grip the bolt and start spinning the ball joint, meaning you couldn’t tighten it properly. In my case, the best solution was to re-use the old nut. Some people will tell you that is heresy, but you can figure on adding a few hours to this job to remove the CV joint if you want to make room to use the new nut. Given that the nut is only torqued to 33lb.-ft., it won’t have been under a lot of stress previously, so in my view, it’s not worth the effort to use the replacement.
With the ball joint in place, use a punch or screwdriver to align the holes on the subframe mounts, and refasten the bolts. Then reattach the anti-roll bar link.
The final step is to finish fitting the new tie rod. So that your car is not wildly out of alignment, you’re going to want to take some measurements first. Using a micrometer, take the old tie rod and measure from the start of the threads on the inner tie rod to the point the locking nut sat. As you can see, I did this after removing everything from the car – it is probably easier and slightly more accurate to do it whilst the old assembly is still in place. Take that measurement and carry it over to the new tie rod, spinning the tie rod end on until it reaches your measurement. Then reattach the tie rod to the hub.
Once you’ve done that, torque everything down. The only fasteners that you won’t be able to properly torque are the ball joint nut and the inner tie rod to steering rack, unless you have a torque spanner. Here are the torque specs:
Front subframe mount: 74lb.-ft. + 1/4 turn
Rear subframe mount: 52lb.-ft. + 1/4 turn
Anti-roll bar link: 33lb.-ft.
Ball joint: 33lb.-ft.
Tie rod end: 33lb.-ft.
With this, the job is complete, and your suspension is fully refreshed and reassembled. The only thing left to do is to have the car aligned. After this, you should notice it riding and handling much better again.
Here are some photos of the front end after reassembly.
Rebuilding the front suspension on the Leon (and related A4-platform vehicles) is a simple task. As you can see above, there are not many parts involved, and the whole job can be done with basic hand tools.