31 31 … Instructions on handling the BMW spring tensioner
The following description refers exclusively to the spring tensioner currently sold by BMW.
Older spring tensioners may only be used in the model series mentioned in the relevant repair instructions if there are no corresponding spring holders for the current spring tensioners.
The spring tensioner may only be used in conjunction with the relevant BMW repair instruction (latest edition).
Observe the following instructions to avoid any risk of injury by the coil springs.
- Prior to each use, check the special tools for defects, modifications and operational
- Damaged/modified special tools must not be used!
- No changes or modifications may be made to the special tools!
- These special tools are intended solely for the purpose of tightening and relieving cylindrical and tapered suspension springs.
- Keep special tools dry, clean and free of grease.
- Impact screwdrivers may not be used!
- Do not compress coil spring to full extent.
- Observe manufacturer’s instructions.
On some vehicle model series (e.g. E60), there is the risk of the spring turning during removal/installation together with the protective insert out of the spring holder. This poses a danger to life!
In this case, the protective insert must not be fitted with the spring holders.
Reference is clearly made to this in the corresponding repair instruction.
The correct spring holders for the corresponding models are specified in the repair instruction.
Locking pins of fixture (2) must be felt and heard to snap into place.
Never tighten or untighten special tools with an impact screwdriver.
Lay upper turn of coil spring into corresponding spring holder.
Turn spring tensioner and position spring strut so that the last turn is flush with the corresponding spring holder, feed spring into spring holder and gently tighten spring tensioner.
Model-specific tensioning specifications are given in the relevant repair instruction.
In some case, a special spring holder (here 31 3 381) may also be used. Reference is made to this in the corresponding repair instruction.
Check correct seating of spring in spring tensioner again
When tensioned, the spring coils must rest completely in the spring retainer recess.
Do not compress spring to full extent.
There should always be a minimum gap (A) between the spring turns. Gap may be ”0” if both these spring turns do not rest on each other all round.
Screw connection of support bearing to piston rod must not be released with impact screwdriver!
Depending on the model, release nut with corresponding special tool (here 31 2 210) (refer to repair instruction), gripping the piston rod in the process:
Vehicles without EDC: internal hexagon
Vehicles with EDC: external hexagon
For informational purposes only.