tips in determining which CV joint?
 

I drove home with what I believe to be a CV joint issue. It was clacking away the whole way home (40 slow miles with hazards on)until I turned onto my street, when it stopped. Now on a short diagnosis trip it didn't do it, and up in the air revving it in all gears it is not doing it. I know this is just a lure to get me to trust it so it can "taunt me a second time".
Is there any tips to figure out which one it might be... assuming it is/was a CV joint? I'd rather not throw $750 at it in new axles without ID-ing the problem specifically.

there's really no way to tell. if one is noisy, service them all. they all went the same distance. cv noise tends to come and go, so the diagnosis is probably correct.

What is involved in a cv joint service?

take the axles out, remove, disassemble and wash the joints in solvent. inspect all the races for divots and pitting, reassemble the good ones, replace the bad ones, and grease the hell out of them on reassembly with moly high pressure grease. good idea to replace all the boots in the process.

Thanks John. I'll tear them both down and take a look. I've also noted that the flange coming out of the trans to the axle is leaking at the trans. Is this easily servicable whil e the axles are out? What's involved?

I'm thinking I paid about $250/axle for new ones. Basically unbolted them and bolted the new ones in. With the labor involved, isn't that a better choice then repacking, greasing, installing the boot, etc?