Hey guys, I may be mistaken, but I do recall hearing people say that 3rd gen rear shocks are interchangeable with 4th gen ones... is this true? Any issues to take into account if doing this? Thanks

 

They are interchangeable. Only the valving varies between 3rd and 4ths.

 

I attempted to install 4th gen rear shocks on my 89 IROC, the bottom mounting is different. One shock (forgot which) has a "O" opening at the bottom, where it slips into a bolt that is attached to the plate on the rear end. The other shock already has the bolt through the "O" and attached to an opening on the plate on the rearend. Not interchangeable.

 

I have rear 3rd gen Bilsteins on my 4th gen TA - no problems.

 

That's because the Bilsteins come with a "removeable" bolt at the bottom (so it can be applied to different applications). The stock 4th gen shock, which is what I was trying to install on my 89 Iroc, has a permenant (not removeable) bolt at it's base so it could not be installed on a 3rd gen car.

 

Something doesn't sound right. Even the 3rd gen Koni's swap into 4th gens. You might want to take a closer look at the mounting points on the axle.

Not trying to be argumentative, but you're the first case I've seen where the shocks don't interchange. Are you the only owner? Is it possible someone did a little engineering job back there? Maybe that bolt is removable.

Good luck!

edit - nice car, BTW!

 

you're correct many of the "aftermarket" brands will fit 3rd & 4th gen cars, because at the bottom of the aftermarket shock, it has a removeable bolt. Actually it comes with the bolt off. You use it if needed. What I did, was try to install "original equipment" shocks off my 94 Trans Am on to my 89 Iroc . Original 4th gen shocks will not fit on 3rd gen cars. The bolt that goes through the base of the shock is pressed on, cannot be removed. I ended up buying KYB adjustables, that's where I saw that the aftermarket brand would fit both 3rd & 4th gen shocks. Original equipment is not interchangeable.

 

Sorry but original equipment is interchangeable also. Did it many times to many cars of 3rd and 4th gen. Sounds like yours is a rather unique case.