I just took my car out of storage since the semester is pretty much done and its recently started to make a thumping sound like I have a flat tire in the rear. It only happens when I'm coasting or let off the gas, basically whenever it isn't under load. I've searched the forum and from what I gather, its probably the front diff mount, but I went to check for any movement and I couldn't find any. What else could be the cause of the thumping, if it isn't the front diff mount.

Thanks

'86 base

 

The front diff mount would be noisy getting under heavy load or off of typically.

 

If it is broken you will hear a clunk in the rear. When you get on it, let off, clutch in, clutch out. Some also call it a thump but I like clunk.

Santiago

 

Thats the thing I'm confused about, the sound that it makes sounds like what a broken front diff mount would sound like, but it occurs when it shouldn't... puzzling