1995 LS400
​​​​​​Does anybody recognize what this oil leak is?




It feels very greasy, so my guess is a bad CV Boot maybe?

 

My guess would be the same as yours but i am not 100% convinced... if so then it looks like pretty much all the grease came out of the boot

What does the boot look like underneath the mess...?

 

That looks too thin to be cv grease. Cv grease is like suspension/bearing grease, thick and gooey. You didn't have a container of oil/trans fluid in the trunk and it leak through the trunk grommets? Is there any fluid where the axles and/or drive shaft meet up to the differential? Could be the shaft seals.

 

I will have to second that. One boot on my '94 had teared on the diff side but the far side away from the cv joint. The grease made a very distinct straight line and was raised like little hills and only in a half inch wide line. Not a huge greasy mess all over the place including the rear of the subframe like yours. I understand after 25 years grease can break down and liquify but not to the point of what we see in the picture.

Hopefully it is not gear oil coming from the diff...

 

Have you checked differential fluid level?

The first image of your rear differential bushings suggests they are cracked.

If extracting differential to replace seals, consider replacing differential bushings.

 

Has anyone checked differential fluid level?

Also, it appears from first image that your rear differential bushings are cracked/separating..

If extracting differential to replace seals, consider replacing differential bushings.