Clunk clunk, only in reverse?
 

When I drive forward, the car sounds fine. When I back up I get a "clunk, clunk, clunk". I've put the car in the air and there is no excessive play in the CV joints and I don't see the exhaust hitting the inner CV and the axle nuts are tight.

Any other ideas, this smells like CV joints.

Does anyone run the Oreilly house-brand axles? They are $80 and Mazdaspeed wants $300.

We have run those axles in multiple cars. They are rebuilt OEM axles.

I think this car has 250 track hours on it, 100 at 250whp...nothing lasts forever In the cold November rain. Neeeeer neeeer neer neer neer ner ner ner ner...

Poppycock! Drive it over to mazda a demand a new axle under warranty.

Every time I drive it to the Mazda dealer here, someone always runs out and asks me if I want to trade it in for a new Miata, lol.

Is it a one time noise?

No, every time I put my thing down, flip it and reverse it.

I'm developing what can only be Ebola S1, so I may need to leave work and while in quarantine for the rest of the day I can work on it.

Any way it could be the ring gear? Suppose I can put the det cans on the case and give it a listen. If it is the 3.63, I will ask Mazda to warranty it. lol

I suppose that if it were it would only make the noise once every 3.6 turns which is roughly every 12-feet and it happens more like every half turn...assuming one tooth is damaged on the R&P.

On second thought, if it is the R&P I'm parking this bitch and buying a smoker, BBQ will be my new hobby.

What I meant was, does it under clunk onces as you engage reverse or is the noise constant as you're rolling?

How about this, do you have the brake hardware on your pads?

Yes, I believe it clunks once with every wheel rotation. I have the brake clippy-springs in the rear, but this is a more substantial clunk, a clunk that sounds like real money, not clippy brake part money.

gotcha. sometimes it's the stupid things...

Are you referring through my build thread? Its usually the stupid things.

Thoughts on broken differential? I've put it through hell.

I have a spare CV I can swap in and out if it comes down to trial and error testing. I suppose this might be a blessing in disguise with the car effectively holding a gun to my head and forcing me to buy a Giken. Why am I excited about this? lol

if it was the differential, why does it only happen in reverse?

friction surfaces turning another direction...I guess. I suppose I'm to the point now where I need to start swapping axles to see if it goes away. It sounds like a loose wheel to me, but that ---- is tight.

Does it only happen when the actual transmission is in reverse or anytime the car is moving backwards? If you put the car in neutral and push it backwards car you hear the noise?

Will check later.

CVs are tight with no slop, some noise from the brake pads, no strange noise from the rear end, front U-joint is tight on the drive shaft.

Is this normal slop in the rear end?

i dont think there should be quite that much...

Could it be something funky with the lower tooth number on the ring considering its a 3.63?