Bummo:
I think I have a single clunk when I go from reverse to drive.
Is this the normal clunk when you shift an auto into gear?
and a double clunk (thats "clunk..clunk real close together) when I go from D to R
The second 'clunk' is the same as the first or slightly different?
The reason I ask is I have a manual and it 'bucks' a little when reversing. I have concluded that the chain in the TC is stretched (slack between front and rear driveshafts confirmed this - See below for test.) IMO, the first clunk is the normal "Initial load" clunk.
When you shift into reverse, the trans starts turning backwards, taking up the slack in the top of the chain till it snaps tight against the o/p shaft. "Clunk!"
To test TC Chain (This is just like a timing chain slack test): With the wheels chocked, Shift TC into 4Hi and Trans into N, hold rear shaft and try to turn front shaft. If it turns more than a degree or two, the chain is stretched. [If you have CAD system, shift with engine off so the front axle doesn't lock, If you have manual hubs, just make sure they're unlocked.]
Also, check U and CV joints for play. Grab each end of each shaft and try to wiggle it up/down and left/right. If the joints move at all in any direction, they are worn and must be replaced. Worn joints also create slack in the driveline which could cause the second 'Clunk'
Just my $.02, Hope it helps!
Peace,
Matt {peace}