HOW TO: 964 SUSPENSION PART TWO
Our wide-ranging 964 suspension overhaul continues, this month with the encouragingly straightforward process of extracting the four struts and the rear anti-roll bar. Text and photographs by Chris Horton
Further update for our 964 suspension project in conjunction with Eibach, Bilstein and Center Gravity
The story so far: two months ago, in the August edition of the magazine, we left Chris Howell’s 964 Targa on the combined lift and geo rig at Center Gravity in Warwickshire, in the early stages of what would prove to be more or less a full suspension overhaul, using brand-new Bilstein dampers, Eibach Pro-kit springs, and anti-roll bars from the latter
company’s recently launched Classic range. Also fitted would be a number of the top-quality Australian-made polyurethane bushes from Superpro. CG proprietor Chris Franklin and his assistant, Peter Leason, had closely inspected – and measured for its inherent ‘straightness’ – the barn-find car from end to end and, having made sure they had all the relevant new components, were ready to begin.
Remarkably – or perhaps not for two such highly experienced experts working together – the job was completed within around 12 hours. Even so, I came away with several hundred close-up photographs of this multi-faceted and genuinely absorbing operation, and as a result have divided the story into several instalments. Shown in this second part, then, is how Chris and Peter removed the four spring-
strut assemblies and then the rear anti-roll bar – with some invaluable tips and tricks of the trade. That wasn’t precisely the running order on the day, and it would have been logical to include here the front ARB, but by that stage – and, as I say, with two people working on the car – any chance of videostyle ‘continuity’ was a distant hope. (And that lower front end will arguably need its own separate story, in any case.) No matter, though: it will all come out in the wash, as the old saying goes.
Next time – which probably won’t be next month; we don’t want to overdose you on suspension, 964 or otherwise – we’ll have a look at stripping and rebuilding those struts and, space permitting, the slightly unorthodox methods required to extract that front anti-roll bar without further major surgery, thanks to our old friend galvanic corrosion. After that it will be refitting the struts, and getting to grips with wishbone bushes, before the final big build-up. I hope you enjoy the ride. PW
The 964 was famously the first 911 with ‘conventional’ spring struts, as opposed to the torsion-bar springs of the Carrera 3.2 and earlier models. In some ways this makes the suspension more difficult to adjust to suit one’s taste, but by the same token it became – relatively speaking – much easier to remove the units for overhaul or, as here, complete replacement. As ever, though, don’t attempt work of this nature unless you really do have the necessary knowledge and tools – and ALWAYS make sure the car is safely supported before venturing beneath
The key to quickly and easily removing the front suspension is having socketry man enough to undo the potentially very rusty nuts and bolts securing each hub assembly to the lower end of its strut – after non-destructively disconnecting the pad-wear and ABS wiring, of course. Ideally, that nonoriginal hydraulic brake pipe would be replaced with a genuine Porsche item – or even just a better-made copper one – but in this particular car that’s a job for another day. To avoid breaking the connection, and so later having to bleed the system, Chris Franklin simply cut a slot in the mounting tab at the base of the strut, allowing the pipe to be slid out. Looks a bit brutal, but it’s what most experienced Porsche technicians would do in the same circumstances. With strut disconnected the heavy brake disc and caliper will hang as in penultimate pic, right, so support them on suitable blocks of wood for the duration
Up top, as it were, the strut is attached to a special mounting plate, itself secured to the body by four M8 nuts (and here with the slight added complication of a transverse brace). Undo them, ideally with an assistant taking the weight of the strut from beneath, and this (near left, top row) is what you will be left with. Brown gasket will need to be replaced, so buy some before you start. Note, too, that the mountings should have been fitted in a particular way according to the car’s specification. On this standard C2 the one on the right-hand side of the vehicle should have the green stripe facing forward, but the one on the left side with the stripe toward the rear. Fitting them with both stripes facing the same way, whether to front or rear, will generate all sorts of weird geo problems. But note, too, that both can be reversed to offer the level of increased camber you might wish from a track car. Rear struts have their upper mountings tucked away at the front of the engine bay, and secured with three M8 nuts. Undo those, being careful not to drop them, and release the large bolt at the base of the strut, attached to the trailing arm. Corrosion on the height adjusters means that these would effectively be permanently locked, but that won’t be a problem with the new ones. Porsche springs are rather crudely colour-coded for identification (far left); these are clearly the originals. Removing the front anti-roll bar will be, as we’ve suggested, a bit of a mission (see next instalment), but the one at the rear is straightforward enough – badly corroded fixings notwithstanding. Again, no worries on that score: all the old hardware will be ending up on the scrap pile. Superpro bushes, made in Australia, are CG’S choice: great quality, and easy to fit. More on these next time