My cv axle spit out all the grease but the boot is still on tight what would do this
Do you have a picture you can post? Also, can you mention the Year, Make, Model, Mileage, Transmission? Thank you.
If the boot is clamped on tight and leaking then logically it must be torn somewhere even if it's not obvious.
If you've been running a CV joint without grease for a while it's toast. Usually it's easiest and most cost effective to just replace the entire axle with a new one.
On my truck it was an axle seal (front differential) that had to be replaced, the boot was just fine. Not sure what vehicle OP has - I asked them to mention it and provide a picture to be more clear.
Good point. What appears to be CV joint grease leaking out could be coming from another source, depending on the vehicle.