I'd bought Autotech Sway bar front/rear many years ago for the Endless Corrado project. The front and rear bars theoretically worked well as a complete set. So I bought both. The front solution simply replaced the existing front sway bar. But unlike the front, the rear was a little different.
The Autotech solid sway bars are very well built. They really tighten up the suspension and really improve confidence while driving in hard turns. But unlike the front bar, the rear bar does not replace the original rear sway bar. The OEM rear trailing arm incorporates an internal rear sway bar integrated into the trailing arm. The Autotech Rear sway bar supplements this existing rear sway bar.
To complicate matters, the rear sway is mounted on different axis points within the suspension and therefore, if not properly designed, the addition of a second sway bar could conflict with the geometry of the existing bar. This is simply because the bars do not mount or pivot at the same points within the rear suspension. As the rear suspension moves within it's travel, the two competing sway bars work against each other as the suspension travels through it's movement. All solid mounted aftermarket sway bars have this inherent conflict. (And they hoped you wouldn't notice)
Unlike other aftermarket sway bars, Autotech had a clever solution which allowed the rear mounting points to slide along the bar. This method would more closely match the existing bar by dynamically changing the rear pivot points depending on the position of the rear trailing arm. This unique approach allows the Autotech rear sway bar to supplement the action of the existing sway bar in the rear. And this was the reason why I originally bought this sway bar. All of the other aftermarket bars used static mounting points which can work against the suspension. The Autotech package included beefier links, mounting hardware, and polyurethane bushings. The other aftermarket sway bars I'd used were not quite as stout as the Autotech version and I often broke the linkages while driving hard into the corners. The Autotech product is well made.
I opted for the solid bars because due to budget. But this bar is heavy! I would guess roughly 15 lbs! This is significant addition to unsprung weight. Autotech did offer a lightweight hollow version which was even more expensive.
After years of driving on this setup, not all was perfect with the aftermarket bar.
The lower mounting point utilizes Heim Joints and a longer mounting bolt that passes through the bottom mounting hole of the rear shock.. This addition adds an extra centimeter to the mounting hardware reducing rear suspension clearance on the inward side. This means the longer mounting bolt is closer to the gas tank on the passenger side and the muffler on the drivers side.
After years of driving, I noticed the rear trailing arm flexes more than I imagined. I did notice contact marks where the bolt does make contact with the gas tank. On the other side, there is a small dent and scratches where the sway bar bolt made contact with the Borla Muffler. I would surmise that the aging rear trailing arm bushings begin to loosen up with age causing more unwanted lateral play of the rear trailing arm under hard cornering forces. I feared this extra movement would eventually wear a hole into the gas tank if I continue on this path. I also recognized the same on the muffler side. So I made the decision to delete the aftermarket sway bar and return to original OEM configuration.
This means that I would need the original shorter shock mounting bolts. Of course, I could not find the original OEM bolts in my old parts bin. Nothing comes easy! That's par for the course for me and my Corrado project. So I had to order a pair of the original length bolts from the local VW Dealer.
The original bolt that came with my car is a 17mm. The newer bolts I ordered from VW utilize 16mm heads. That was surprising and caught me off guard. All of my socket sets and box wrench sets do NOT include a 16mm tool. I wonder why VW/Audi would begin to use 16mm bolts? My Audi used 18mm bolts (Another box wrench and socket that isn't utilized in industry.
The rear suspension has now been fully reassembled.
I don't regret using the Autotech suspension enhancements over the years, but I don't want to further an inevitable replacement of a gas tank and muffler. I'd much rather enjoy the weekend drives and not worry about punching a hole in my gas tank.
On to the next item.
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