Astra G & H, Corsa C, Vectra B Pillowball top mount fitting guide


As always with all motorsport products professional fitting is recommended for them.


Periodic checking of all nuts and bolts is required, along with frequent lubrication with PTFE based maintainence spray.


Lubrication best achieved by lifting front axle off of ground, spraying lube down into the top of the bearing unit and moving steering from lock to lock multiple times. If they start creaking then they need lube, if you do not lube them they will eventually sieze the bearings and wear out rapidly. Road salt is their enemy, and too much pressure washing, they were designed for the race track but looked after well will last on the road too.




     5 x Stainless locking grub screws per side




     Lock ring




     Damper top nut





     Main top mount body




     Lower Spacer (Not used on Astra H type M14 x 1.5mm setup)


     Standard Spring cup adapter washer (built into lower spacer on V2 top mounts, and not used at all on Astra H)



     Damper rod








Here is the basic order of assembly for the spherical top mounts;



Remove your front shock units from the car and follow the usual procedure for spring removal. If you haven't worked on the suspension of your car before then we would highly advise that you get a professional to do this, as loaded coil springs can be incredibly dangerous.


Remove the standard top mounts from the shock units.


If using standard type spring cup units, tap out the standard bearing from the spring cup and fit the standard spring cup spacer and continue to build the top mount as pictured above. A blob of blue loctite is a good idea for the top nut when fitting it to the damper top.


If using a Coilover shock or anything similar that has its own built in spring cup, it is usually not necessary to use the standard spring cup spacer. If it looks as if it would be a good idea to use the spacer on your particular set up then please feel free to do so.


The Mk5 / Astra H does not use the spring cup spacer at all, instead the original plastic spring top bearing unit is refitted to the bottom profile of the top mount. Again, these can be done away with in the case of a coilover unit with it's own spring cup system.


The whole strut unit can them be mated up into the car, attach the alloy locking ring to the bearing body and screw it down as tight as it will go. You will have recieved two longer M6 bolts with the kit, these can be screwed into the lock ring at opposite sides to allow you to use a spanner across them to tighten the lock ring up. Be sure to fit the tightening bolts into the threads as far as you can, if you finger tighten them until they bottom out, then back them off half a turn, then this should ensure you don't damage the threads when tightening (see last 2 pictures below if this doesn't make sense)

Once they are tight you can insert the m6 grub screws to lock the assembly in place. One screw will do, but we put 5 in to allow you to tighten them up with the simple method mentioned before, and because they looked nicest with 5.


Go for a gentle drive, checking for any knocks or bangs. There shouldn't be any if assembled properly. These being solid can sometimes highlight other problems, so check everything else on the suspension too if you do find you have some noises being transmitted through the chassis and you have fitted the mounts properly.


If you have any other questions about fitting these then please get in touch at;