I don't know how many replace the mounting bolts but I've never replaced them and I've done many timing belt jobs.
Only when at work we have to replace the bolts and that's for recalls or warranty work. If the customer doesn't request replacement when they come in themselves and ask for a replacement belt kit, we will reuse the old bolts but do recommend renewal.
So if your engine rocks like dazzas video, your gearbox mount is failed?
ive had the engine reved in park mode before and watched the engine and it rocks back and forth maybe an inch. I'll have to take the cover off and rock it like dazza did to see. Is he just rocking the whole engine?
99% of the time the mount is badly worn as I had this with mine when purchasing the car but it was okay when I went for the test drive. Only when I paid the deposit and then went for collection is when I found the car to be jerking as one of the traders workers was driving it back from some where!!! I think the baaskeeet was hammering it as it felt jerky on the was home which is why I assumed ds box fault. Later found mount was knackered.
Hope this helps along with the video dazza kindly put up.
M