[Stephen Edwin]

Re the old messed up shaft in the previous gear box, let us not ignore that, just in case. Incidentally in general I'm curious or possibly concerned how that happened.

The replacement gearbox, who fitted it, skimmed the flywheel and refitted the gearbox?

Does the banging sound and feel like something internal to the transmission, or like knocking against the body of the car? I get the impression you are talking about knocking against the car body? Can you get the use of a mechanic's stethoscope and would that help?

If the engine is ticking over, and by laying down on the ground to listen, is there any knocking even a gentle tapping sound? If so can that sound be relieved by say slightly supporting the gearbox on a jack?

Looking also at the timeline, and with experience of a similar problem on a car of a different make, my hunch is engine and/or gearbox mounting[s]. That is even or perhaps especially if the mountings or any of them were replaced recently.

Perhaps replace all the engine and transmission mountings. Using genuine Volvo parts. Try to do it by supporting the entire engine/transmission assembly so the mountings are not under strain during the process. Then, with little or no weight or stressors on the mountings, tighten them up incrementally. Tighten each mounting a little at a time, in turn one by one. If any sort or form of resistance is encountered, try to check it out before continuing. Get the whole situation as stress free for the new mountings as possible. Do it thy self or see it done.

You have mentioned to me a vibration of a different component at or about a particular road speed. It does sound unrelated. But ... I suggest always keep an open mind.


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