Jerkiness in transmission

[gouldsborough7]

I am beginning to notice a certain amount of slackness/jerkiness in my Hunter's transmission, mainly when changing gear. I guess this could be accounted for in a number of areas: worn propshaft u/Js, the diff, and axle mountings. Has anybody ideas on how I should go about identifying this? Ideally, this would be easiest to do on a professional hydraulic hoist 6 feet in the air. The best that I can do is raise the car on trolley jacks and axle stands.
Cheers
Mike