[Organic1]

This oddly started happening immediately after I put on new plugs and wires, I think I had a miss, so now I have more power. This is happening all of the time. When I let out the clutch slowly, as soon as I begin to let it out, I get this fairly hard jumping that is transferring to the rear wheels then goes away when I let all the way out and start moving. I suppose it's possible that what I'm feeling is coming thru the clutch pedal but it feels like it's coming from the rear drive. I have a few theories but don't really know enough about clutches, transfer cases, gear boxes and that sort of thing to really guess what it is.

 

[Ken Allistone]

Thrust/release bearing on the clutch, does it do it if you let the clutch out gently with lower revs, hard to say without trying it but judder is very common, if unsure then ask an experienced mechanic, should be obvious to them.
Could be that like most 4.1 rav's you also have play in the diff and worn/soft diff mounts which don't help either.