408537 Disassembling and assembling front spring strut - with and without PASM
WM 408537 Disassembling and assembling front spring strut - with and without PASM
Tools
Information
Component and assembly overview (with and without PASM)
There are three different types of running gear: standard running gear, sport-type running gear (Performance) and PASM chassis.
The 911 Carrera S comes with the PASM chassis as standard.
Front spring strut, exploded view
Disassembling and assembling spring strut
Disassembling spring strut
CAUTION
Increased risk of accidents due to spring tensioning.
- Danger of injury and damage from springs jumping out.
-> Never use an impact bolter to loosen or tighten the fastening nut.
-> Use a commercially available changeover ratchet.
1. To prevent damage (deformation), clamp the spring strut in a suitable clamping block (tensioning device for MacPherson spring struts). Alternatively, the spring clamp can also be held in a retaining device.
2. Pre-tension the coil spring using spring clamp for spring struts NR.121 until the piston rod is relieved. The appropriate forks must be inserted into the spring clamp.
Tensioning front spring
3. To loosen the lock nut (piston rod to spring-strut mount) use socket-wrench insert P 9630/2.
When loosening the nut, counter it at the piston rod (for conventional spring struts) or at the two grooves (cut-outs) of the stop plate (for PASM spring struts). Tools required: retaining tool P 9630/1 and for conventional spring struts arm bracket P 9630.
Spring strut supporting mount (PASM version)
4. Remove all parts from the piston rod.
Coil spring/compensating plate allocation
Identification marking -A- comprising two coloured lines is for the spring constant and spring length (depending on vehicle version and equipment).
Colour identification of spring/damper
Identification marking -B- comprising one coloured line (white or green) is for the coil spring tolerance range (load group) and determines the thickness of the spring plate (compensating plate).
The spring plate (compensating plate) comes in two thicknesses -arrows-.
Spring plate (compensating plate)
1) If you are installing new coil springs, then order the 3.5 mm and 6.5 mm spring plates (compensating plate) at the same time. As coil springs of load group 1 or 2 will be supplied, the correct spring plates (compensating plates) will then be present for installation.
2) In production there have been deviations from the general allocation of spring plates (thickness of compensating plate), in some cases different spring plates (compensating plates) have been installed. This was necessary due to the tolerances of the coil springs. This means that in the event of replacement: If the coil spring is to be re-used, then install the spring plate (compensating plate) with the same thickness. If the coil springs are to be replaced (only replace in pairs) then the allocation given above applies.
Allocation of vibration dampers
See allocation in Spare Parts Catalogue.
The marking, item number and colour dot coding -C- are shown on the damper tube.
Colour marking of spring/damper
Assembling spring strut
CAUTION
Increased risk of accidents due to spring tensioning.
- Danger of injury and damage from springs jumping out.
-> Never use an impact bolter to loosen or tighten the fastening nut.
-> Use a commercially available changeover ratchet.
Information
- Observe the correct allocation (vehicle version and equipment) when installing new coil springs and/or shock absorbers.
- Observe allocation of compensating plate according to the coil spring tolerance range.
- Coil springs are only available in pairs.
1. Clamp the spring strut in a suitable clamping block (tensioning device for MacPherson spring struts). Alternatively, the spring clamp can also be held in a retaining device.
2. Slide the bellows/additional spring assembly onto the piston rod.
3. Mount cone washer -8- and stop plate -7- in correct position.
Cone washer
4. Push the pretensioned coil spring onto the vibration damper so that the end of the coil spring rests against the stop of the spring plate.
5. Completely assemble the spring plate (compensating plate) -6- , support ring -5- and bearing with its housing -4- with the spring strut supporting mount -3-. Then slide the assembly onto the piston rod.
Supporting mount assembly
6. Place spring strut supporting mount assembly onto the piston rod so that the end of the coil spring is located inside the spring plate.
7. Fit stop plate in the correct position (domed side upwards) and screw a new fastening nut onto the piston rod. Important: For PASM spring struts, place the lug of the stop plate (in area of spring strut mount) in the groove of the piston rod (twist lock of piston rod opposite the supporting mount). Make sure that the plastic part of the bearing sits correctly in the recess of the supporting mount -arrows-.
Supporting mount (correct seat)
8. On PASM spring struts, before tightening the lock nut, align the stop plate -2- offset 45° from direction of travel marking -Arrows A- of the supporting mount.
Stop plate position (PASM only)
The value: 45° + - 2° is necessary so that the two grooves of the stop plate (cut-outs for countering) are positioned over or between the recesses (pockets in the rubber part) which lie below.
9. Tighten fastening nut to the specified tightening torque. For PASM spring struts, counter at the stop plate using retaining tool P 9630/1. For conventional spring struts, counter at the hexagon socket of the piston rod using special tool P 9630.
Spring strut mount
10. If present, push on clip (vibration balancer) at damper tube of vibration damper. Final assembly (tightening) only on completion of wheel carrier.