Hey guys, I have been experiencing this issue for a long time. When I let off the throttle or get on the gas there is a noticeable "Clunk" coming from the rear. I have done a lot to try to resolve this, U-Joints, changed the dif fluid, and even changed my driving habits. What am I missing? Its a gross noise and it is quite distracting, and I hope to resolve it. Any help would be appreciated.

Thanks

 

My general advice would be to try to isolate the problem the driveline or the suspension, or the brakes. For example does the clunk happen when you hit the brakes to decelerate? Or does it only happen when you hit the gas or let off the gas?

I would get it up on a lift. Get a pry bar and start trying to move things around looking for obviously loose components. Definitely check bolts and bushings on the suspension members.

 

The symptoms you describe sound a lot like differential backlash, you mentioned you r/r the differential oil, and replaced the driveshaft u-joints. Did you do the work or have it done? If I'm not mistaken the original RX7 OEM driveshaft u-joints were not replaceable, so that would indicate that the cars original driveshaft was replaced somewhere along the way. I would suggest put your car in gear and grab your driveshaft and try to rotate it back and forth and see how much play there is. There should be a "little" movement back and forth, but not to much if there is too much play that could be what's causing the "clunking" on accel/decel.

 

Hey there thanks for the reply. I did the work myself. To my knowledge certain years have replaceable U-joints, mine included. I will try that test however

 

The drive shaft with the stacked u-joints are the ones that they say cannot be replaced. A driveshaft shop had no problem replacing mine once I gave the the replacement u-joint to use.

Rockford Driveline Speciality Universal Joint :: Rockford Driveline

Speciality 'STAKED-IN' Replacement U-Joint

Model Number: 430-10A

 

When I mentioned "replaceable" u-joints I was referring to ones you can replace yourself, not take to shop.