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

911 Porsche World - - Contents -

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

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