vanHunks

The rear shocks on my 2004 GT3 need to be replaced. My OPC reckons the rear suspension must be disassembled partially to make enough room to remove and insert the struts. Moreover he asserts this is the approach recommended by Porsche to dealers.

Apart from the additional labour this creates the requirement to CC&A (check camber and alignment ?) so that total labour time is just under eight hours, which seems ridiculous to me (4.2 to remove / replace struts, 1.0 to disassemble/assemble the struts and 2.5 for the CC&A).

I was wondering :

1. Is this really Porsche's recommended approach ? It doesn't seem well-suited to the quasi-racing role of the GT3.
2. If so, is the time allocation correct (that is, Porsche's standard rate) ?
3. Is there a clever way of doing this, that avoids the suspension disassembly ?

The manuals/information to which I have access are frustratingly silent on this specific job. If you could let me have the correct procedure number this would be of great assistance.

Thanks, Dominic

ninerguru

Here's a writeup I found for a Boxter... I think it is similar to GT3.... It will give you an idea of what needs to be done... http://gwl.rmsolo.org/hacks/suspension/#front Hope it helps...

911SLOW

Disassembling and assembling rear spring strut - GT3



The spring strut has a thread and a height adjusting nut No. 2 for height adjustment. The height adjusting nut No. 2 is secured against turning by the lock nut No. 1.
The stabilizer block - No. 4 - (mounting saddle for the stabilizer mount) is also fitted on the thread. The stabilizer block can be vertically adjusted and it is provided with a lock nut No. 3. This adjustment possibility is only useful for racing. It can be used to ensure that enough clearance is available for the stabilizer mount even for deviating vehicle heights (only for racing) and also that the stabilizer mount can be fitted free of tension.

The stabilizer block No. 4 does not need to be adjusted for the vehicle height prescribed for street use.
The stabilizer block No. 4 - dimension B and dimension C - is also set with replacement dampers.

1 - Lock nut
2 - Height adjusting nut
3 - Lock nut
4 - Stabilizer block


Dimension A = pre-setting dimension for production (185 mm). The dimension may be different with the prescribed vehicle height.
Dimension B = 105 mm (plus/minus 1 mm)
Dimension C = 90 degrees (see illustration 42930001)






1
Fastening nut M 12 x 1.5

1
If necessary, pre-tension the coil spring with the spring clamp before loosening the lock nut. This depends on the pre-tension of the coil spring.
Support at the piston rod with a 7-mm open-ended wrench when loosening the nut.
Use new fastening nut.
Tighten to 60 Nm (44 ftlb.).
First position the spring strut mount (No. 3) (see under assembly instructions).

2
Disc (stop plate)
1
Mount in correct position (No. 2 and No. 6 are identical parts).


3
Spring strut mount
1
The mounts for the right and left sides are identical parts.
Position the mount before tightening the fastening nut No. 1 (see under assembly instructions).



4
Spring plate
1

5
Coil spring
1



6
Disc (stop plate)
1
Mount in correct position (No. 2 and No. 6 are identical parts).



7
Washer
1


8
Additional spring
1


9
Vibration damper


1
The vibration dampers for the right and left sides are identical parts.




Disassembly
– If necessary, tension the coil spring with the spring clamp until the piston rod is relieved.
– To undo the connection (piston rod to spring strut mount) counter at the piston rod with a 7-mm open-ended wrench. Important: Never use an impact bolter to loosen or tighten the fastening nut.
– Remove all parts from the piston rod.

Preliminary work and notes on assembly
– Replace nut for fastening the piston rod on the spring strut mount.
– It is recommended to replace the coil springs only in pairs.


If the vibration damper is to be replaced, set the height adjusting nut No. 2 to the same position as on the old vibration damper (transfer the actual dimension A to the new vibration damper).

A hook wrench insert - special tool (Porsche calls it 9647_) - is required for this purpose.
It is required to change the vehicle height (dimension A) and to adjust the stabilizer mating bearing No. 4 - on the front and rear axles.
The special tool is used together with a torque wrench to tighten the lock nuts (slotted nuts) on the spring struts.

Important: The stabilizer mating bearing (mounting saddle No.4) need not be adjusted for street use.

1 - Lock nut
2 - Height adjusting nut
3 - Lock nut
4 - Stabilizer mounting saddle





Assembly
– Push additional spring No. 8 onto the piston rod.
– Slide the disc No. 7 and stop plate No. 6 (stop plate No. 6 in correct position) as far as they will go onto the piston rod.
– Place coil spring in the correct position - tighter winding facing down - on the vibration damper.



The coil spring is equipped with an approx. 50 mm long protective sheath at the top. This protective sheath is not yet present on vehicles from the initial production run.


A - Top
B - 10 mm
C - Protective sheath approx. 500 mm long

– Place spring plate on the coil spring.
– Place stop plate in the correct position on the spring strut mount. Screw new fastening nut onto the piston rod until approx. 1 to 2 threads are visible above the fastening nut.
– Position the spring strut mount for installation (correctly position spring strut mount with respect to the damper).
Information

The mounts for the right and left sides are identical parts.

– The spring strut mount is positioned correctly if one of the 3 fastening pins is aligned with the stabilizer mounting saddle.


– Once the mount has been positioned correctly, tighten the fastening nut to 60 Nm (44 ftlb.) . When tightening the fastening nut, hold at the piston rod using a 7-mm open-ended wrench.


Never use an impact bolter to tighten the fastening nut.

AudiOn19s

I just installed suspension on my GT3 recently, the rear really is cake to do. Honestly It'll take longer to dis-assemble the OEM unit to get the spring perches and drop link collars off and switch them over to the new unit than it takes to actually get the coilover unit out of the car and back in.

There is a good bit of time in getting ride heights correct once everything is together if you're being really picky about it. I probably had 2 hours in getting ride heights exactly where I wanted them once everything was together. this was setting both front and rear though.

Andy

spare tire

I just installed new springs last weekend. Removing one rear strut can easily be done in less than a half hour. My spring perches were frozen in place due to not being spun or moved in years. So expect trouble spinning them off. I just did the job with my new JackPoint Jack Stands in my yard.
1. 8 hours for both is reasonable.
2. the suspension does not need to come appart.
3. one hour to jack up car and pull both shocks
4. Minimum one hour each side to remove perches and springs
5. one hour to reassemble new shocks or rebuilt shocks. ( both)
6. one hour to put them back on the car (both)
7. That is 5 hours of work so far and to corner balance and align 3 hours in reasonable = 8 hour day
8. You could do it yourself in 8 hours and that gives you time to solve the little problems that will happen.
After you have done it once and all the threads and bolts are free of corrosion , then you could do it in 4-5 hours total.

vanHunks

Gentlemen, Thanks for your replies. My concern was the necessity or otherwise of the partial disassembly of the rear suspension to remove and fit the struts and it's clear this is not necessary. Now to persuade the OPC !

GT3 Racer

Take off the OE stuff and replace with Motons I have for sale in the parts section!

vanHunks

The start of a slippery slope. In fact the front struts were replaced recently under my used-car warranty and I'm committed to the new rears. Perhaps when another 90,000 kms have rolled under the car . . .

runet

Just wanted to add a couple of points to make sure others wanting to do this have the info straight:
To remove the whole strut from the car all you have to do is remove the 3 nuts from the top mount (inside the car) and the bolt at the bottom. The strut can then be pulled straight out, no other parts of the suspension has to be removed.

To dissasemble the strut you do not have to use a spring compressor, if you turn the hight adjustment nut down you can release all the tension from the spring before loosening the single top nut to dissasemble the strut.

MTB

And to lift the back end up, so no tension on swaybar, then remove the swaybar link.