Originally Posted by acf5
Update: clutch needs replacement, PO overheated it at some point
How do you know it's overheated? A broken transmission mount will cause a feel like that when floored.
Also, I have a 99 TJ with 58k miles, my engine mounts, transmission mount are all in good shape, but I will occasional get this shudder you are talking about. In my case I think it's a tad bit of oil out the rear main seal that gets on the flywheel. Not a big deal because it isn't that bad and doesn't bother me that much.