I'm pretty sure I can rule out suspension since it doesn't do it on bumps.
The hubs axles and diff are from a JDM STi
Only does it in reverse when taking up the drivetrain slack, and when letting off the gas. (basically the same thing - whenever the rear end experiences torque in the opposite direction of normal rotation it clunks)

It's always been there to some extent even before all the AutoX and RallyX stuff I've been doing.

All the bushings are relatively new as I put all new ones in as part of the swapping process. The clunks is rather loud, Ryan and Ian have heard it. It sounds like its coming from the driver rear side.

I'm going to check for play in the wheel, maybe its a wheel bearing, but then again no unusual whirring noises associated with that.
Going to double check the torque on the axle nuts and maybe swap the axles around to see if the noise switches sides.

The only other thing I can think of is maybe there is some play in the axle CV joints? or the parking brake shoes are shifting around?

 

Subscribed because I have a similar clunk and I CANT FIGURE IT OUT! I've gone as far as replacing my Diff, and Propeller shaft to try and solve it. Replacing Axle nuts fixed it for a little while, but it came back!

 

Axle nuts. Get new ones and torque to spec. I had a click appear after a Solo event once. I thought it might be the diff and or associated bushings. Changed the rear driver's side axle nut and the noise went away.

 

You can't tell by looking at them right? The "lip" can be bent over properly and still warrant repair right? Anyone try locktite the new ones and bend it?

 

You can't tell visually. You just have to do the job. Always use a new nut.

 

See, I did that. And it came back.

 

Did you torque it to spec?

 

I believe it's the rear subframe bushings between the subframe an the doff, Kartboy or TIC offer a bushings kit to stiffen them up I believe.

 

i just talked to jared. he said he already changed all of that

 

Yes. Last time I was in Subaru, I bought like 8 axle nuts. Would torque to spec, crimp it down and it would go away for a few days then come back.

 

Since it goes away each time he changes the axle nuts, then it's the axle nuts. Now to figure out why they keep losing their clamping force???

 

hah, no thats just me. I totally jacked Jareds thread, I think his is something different, it sounds NASTY.