Outer Limits 4x4 Board

First time user of this forum. I recently had new Nissan engine mounts & gearbox mounts fitted to my 1991 GQ 4.2 Diesel with auto gearbox. Since then, every time I switch off the motor vehicle it shakes for a second & then I hear a loud knock/bump. Any ideas guys as to what can be wrong.
Regards loughma

dunno but mine does that occassionally, was told it is 'normal'

Next time you go to turn it off hold the revs up to 800 or 900 rpm and then turn off the key, see if that stops it

mine used to do that, it was the exhaust on one of the cross members, just jump under and see if you can see any wear marks