On my 83ZX, I notice the car really sits hard in the rear when I shift. It feels like it hits the ground. I know it doesn't actually hit the ground but I can feel a thump through the seat as if the rear has bottomed out. I was thinking the shocks are okay because the car sits pretty level. I thought it might be the Differential Mounting Insulator but I don't know how to diagnosis that without taking the rear suspension apart.

Any ideas, please!!

 

welcome to semi-trailing arm suspension bud.

get new springs/shocks in the rear, that'll help a bit.

 

I guess I could try new shocks and springs. I just figured they would be okay because the car only has 63,000 miles on it and it doesn't sit low in the back like a lot of Z's I see.

 

If you hear a "clunk" it's usually the diff mount, drive line u-joint, or cv's / half shafts. The diff mount is a big chunk of metal & rubber... pretty easy to see any rips. Check your cv's / drive line for play.

Other than that, yes the 280zx has the uber common "squat" on acceleration. Like PurePontiacKid said, stiff springs / struts solve that problem.

 

even my Z with 83,000 miles had bad shocks, well if the shocks are covered in oil there probably bad, an easy test that could give you clue as to if the shocks are bad or not would be to push the car down with some force, if the the car bounces up and down a lot then there probably going bad

 

Lol except for the front shocks which are submersed in oil

 

yea