Clank on Acceleration/Deceleration

Hey guys, need some help pinpointing a clunking sound that seems to have evolved to include a clanking sound on my car upon acceleration/deceleration. Wall of text incoming.

2012 MS3 144,000 miles.

Back in July/August I went through the front end and replaced RMM, PMM, and TMM (all with OEM Mazda mounts), wheel bearings, hubs, ball joints, axles (oem to dta), and a transmission seal on the driver side. Symptoms then were excessive road noise and a humming while at freeway speeds. Replacing the above helped, but didn’t totally solve the noise, which was resolved by replacing the tires.

Once everything was installed, I had about 500ish trouble free miles where the car felt and drove like new.

Around the end of October I was driving home from work and noticed I was getting a clunk shifting 1-2, 2-3 - accelerate, pause (gear change), accelerate, clunk. I was able to pretty reliably replicate the clunk without shifting if I accelerated, lifted and engine braked, then accelerated again, so it’s safe to say it’s related to a change in momentum. The clunk seems to be most prominent near my feet in the driver’s position, so I was thinking it may be axle related.

I didn’t have a chance to check out the car until December, but so far here’s a list of everything I’ve checked:

• Axle nuts tight
• Strut mounts bolts and nuts torqued
• Ball joints still seated and torqued
• End links
• Inner CVs seated on transmission output shafts

Recently I’ve noticed that the clunk is now sometimes accompanied by a clank.

This afternoon I jacked the car up and supported the front end with jack stands and removed the front wheels to inspect everything again in case I missed something.

With the suspension unloaded, I’m still able to recreate the clunk and can reliably replicate the clank: transmission in gear and clutch in with the brakes applied (trying to replicate the load of the weight of the car on the drivetrain and starting from a stop), slowly let out the clutch until the brakes catch, clunk, often with a clank following. So I think I’ve narrowed it down to something driveline (or possibly mount?) related. Turning the wheels does not cause any noise while moving.

The CVs have some play (think car rolling forward or backward motion) that can be caused by hand when the front end is off the ground. That motion creates a sort of clunk, but I’m uncertain if it’s the same clunk I hear while in the car.

The DTA axle part number that I ordered was for the 2nd gen - I realized after the fact that you guys recommend the first gen part number instead.

I’ve snagged some videos of the various noises along my troubleshooting journey. I’ll edit them down and post them as a reply.

Thoughts? Ideas? Thanks in advance for anyone who chimes in!

 

Lower control arm bushings are probably shredded

 

Could be sway bar end links too

 

What’s the best way to upload a video, host on YouTube and post a link?

LCA bushings and swaybar bushings appear to be good. I think a video would be beneficial

 

Just upload here

 

Bummer - even a ten second clip says too big.

 

Alright, here we go. Front end is off the ground with the wheels removed. Alternated between 1st and R. This would take the LCA bushings, end links, struts, strut mounts out of the equation.

https://youtube.com/shorts/qtRrvySRkQg?si=S9K8L_UasLykIaZ6

 

Sadly, that sounds and looks like something in your Transmission.
Certainly not an expert in transmissions, but see if you can rotate each axle hard enough to make or feel the noise, might help you narrow down what is happening.
Maybe check the oil and see if it has any chunks in it.
Hopefully someone has cheaper answer for you to at least try.

 

Small update. Reached out to DTA and they’re going to ship me out a new driver side CV. I don’t think that’s going to do much for the clunk, but it’s a starting point. Might solve the “clank”.