Can any of you clever people help with my back suspension problem? The bump stop on the drivers' side is just touching the upper suspension arm,whilst the other side has a 15mm gap. The strut cones are not the adjustable type. I would like to replace the strut cones and cone springs on both sides,but how do you compress the cone springs when you cannot put the compressor tool on top of the subframe due to it being inside the side panels? Are the cone springs and struts standard mini type or special to the GTM? Is the cone spring bolted to the subframe or does it just sit in the housing,the workshop manual is not very clear? Somebody has drilled a half inch hole directly above the subframe top on the inside panels and I can see down through the cone spring on both sides but this would not help with using the compressor tool. How can I tell what hubs are on the back as I need to replace the dust covers on the top and bottom balls joints so I will replace the complete ball joints. There are no grease nipples where in the mini manual it shows grease nipples. The metro manual shows no grease nipples. The car is fitted with disc brakes at the back. Are the ball joints the same for mini and metro as I jumped the gun and ordered a set of mini ball joints for both sides? Sorry for so many questions but have not messed with dry suspension before. All my other classics are of conventional style suspension. Hope you can help.

Think you need to get the car on a flat surface and measure up underneath to find why you have such a big difference in suspension arm angles if you are using unmodified cones and struts.
The cone compressor bolt should pass through the chassis hole and screw into the cone and when tightened will allow the strut to be removed, good idea to tighten the bolt with the car on the ground, gravity helps

You should be able to use the compressor through the drilled hole although later cars used a larger 14mm thread in the rubber cones.

The height difference may be due to a broken knuckle joint at the end of the trumpet or a badly worn Teflon cup in the top arm.

If you can't get the compressor to work you can still get the rubber spring out by removing the top suspension arm completely. You need to remove the rubber droop stop first.

Thanks for the replies. I have investigated further and on taking the drivers side rear wheel off I found it would not go into full droop position. It is not the shock absorber causing problems as I removed it and still have the problem. Will the compressor tool reach as there must be about six inches of side pod before you get to the hole? Will the fibreglass side pod be able to take the compression if it does reach? Is the cone spring and cone strut the same as mini? I think I will replace both sides and knuckle joints as well.It is a later Rossa 2 but I think the subframes are from early car(2 bolt turret top fixing above cone spring) as it took tax exempt registration from donor car. There is 15mm difference in ride height at back measured just in front of rear wheels on the tub.

Sorry. I didn't notice that we were talking about the rear suspension.

Have you checked the rebound stops. They are there to stop the wheel dropping too far.

Generally the problems come from the rubber spring seizing into its housing and the alloy cone seizing into the spring.

As I said before, it is possible to dismantle the front end without using a compressor.