Hi Howard,
It definitely has some flexibility compared to the 2 X granite like examples I've bought in the last 4 to 5 years.
It looks like I've made some progress with the Volvo mount. The gearbox doesn't sound like it wants to exit the car. I've been up to 70mph in 3rd, 4th and 5th. However I haven't road tested it yet. The front of the car is up on ramps whilst the rear is on axle stands so I've taken the car through the gears in the garage.
Briefly, the Volvo rubber mount has replaced the standard mount TKC1044. Ive slotted the holes in the gearbox crossmember, drilled out the centre hole to 12mm, replaced the bottom mounting plate with a thick washer. The long centre bolt may need replacing with a slightly longer one enabling spacer washers to be fitted as the gearbox tail sits about 9mm lower than before. I'm not sure if that needs sorting or can be left as is.
Gearbox crossmember off the car with lump of granite attached
Volvo mount placed on the crossmember.
The holes in the crossmember line up with those in the Volvo mount but require slotting towards the centre to enable it to fit. As per the Dolly thread I slotted them about 4mm towards the centre using a die grinder in a drill. I could have filed these by hand if I had the patience. I also opened up the central bolt hole in the mount to 12mm and with an angle grinder shaved about 1mm off front and back as its a touch too wide to fit.
This is the mount bolted to the crossmember with the old parts beside it.
The Volvo mount is the wrong shape to accommadate the standard lower mounting plate UKC2209 so I replaced it with a thick washer also bored out to 12mm.
http://www.rimmerbros.co.uk/Item--i-GRID006415The Volvo mount is thinner than the granite mount TKC1044. The Dolly thread packs this space out with 40mm washers. However the large centre bolt only has about 18mm of spare thread to screw into the underside of the gearbox once the spacer and top plate are in place.
This is about the same amount of thread if using the standard items.
I've not fitted any spacer washers since I'm not keen on torquing the centre bolt up in the aluminium housing with less than 18mm of thread engaging, so the gearbox tail is about 9mm lower than standard. The engine, gearbox and exhaust don't appear to be fouling or touching anything but it's not been driven on the road yet. If the Volvo mounting silences the gearbox successfully then I may source a longer bolt to utilise some spacers.
Underside of gearbox
The torque of a RV8 is greater than a Dolly Sprint but I would expect this is taken by the engine mounts and subframe, not the gearbox mount. We'll see how it stands up on the road. Hopefully I'll be able to road test it tomorrow and not have to change the gearbox after all.
Adam