Hello everyone,

Recently I been getting a clunking noise from the rear or the car. I started noticing it going over speed bumps, but dismissed it cause I know I need sway bar endlinks and figured thats what it was.
Last week, I noticed it happens when I first brake. Pulled the back tires off, brakes are fine, nothing loose. So I dismissed it again thinking somehow it was still the endlinks.

This week I noticed it also happens sometimes when I begin to engine brake.

Pulled the passenger rear tire off (it sounds like its coming from this area from in the cabin). Checked everything again, nothing.

Released the parking brake (tranny in neutral) and turned the hub back and forth by hand, This is what I hear from the middle of the car...


How worried should I be? And WTF is it? Driveshaft? Diff? Normal?

 

Not normal, possibly u joint. Cheap enough but, bit of a pain to replace. Thats what i would check first.

 

I thought our U-Joints for the drive shaft were not replaceable?

I would have got a better shot but I was alone and will not get under my car alone.

 

Upon further inspection it looks like it's my differential making the noise.

If I grab the Input shaft of the diff and someone turns the rear wheel back and forth there is a very loud clunking noise...



A quick search on here and someone mentioned changing the differential fluid to stop the clunk, think that would work? Using RedLine 75w-90, about a year old.

Any help is appreciated.

 

Changed the fluid, no change in clunk.. Fluid looked okay, had about 15-20k miles on it. Not much on the magnet either. So maybe thats a good thing.

Now it's clunking constantly when coasting and turning. And there is a odd vibration from the rear @+60mph.

Had a few friends look at it, one thinks it's the driveshaft, the other thinks it's both. I know whatever it is, it's beyond me fixing it in a parking lot so off to Aamco in the AM for a butt raping...

There goes my tire money.

 

Why do you have to work on it in a parking lot?

 

Because I don't own a house yet.

 

Oh, gotcha. I thought you lived in your car or something

 

I just might have to after this! I

 

nah, just find a decent driveshaft shop. Check with your local autocross group.

 

I was actually going to try a used driveshaft from eBay if it's the driveshaft, I found one with low miles for $130 shipped. If that doesn't work out I am going with the mazdatrix one.

 

Just got the rough estimate... $1,300. This includes the diff and half shafts being rebuilt with a 12 month warranty.


Awesomeness....

 

Why would the axles need to be rebuilt? And what is wrong with the diff exactly?

 

They got "free play" in them. I only agreed because I want everything done now while I got the cash.
They mentioned my clutch was slipping, but I think they think that because I have the pedal adjusted very high because I'm a lazy person and have a bad habit of not pressing the pedal all the way in when I shift. The car will lite up the tires in a 1-2 shift pretty easy.

They said the bearings are bad on the diff (I kinda figured that after watching some youtube videos), but they are are pretty sure the gears are fine since I brought it to them while it only had small symptoms still. They are going to rip it apart tomorrow and give me a final total after they see inside of it.


Here is my replacement car for the time being...

 

Shop called me, the parts just came in. Should be ready by Wednesday, and not a moment too soon.

Having the Mazda6 as a car was different (Boring)... By the 3rd day I realized there was no point in flooring it, it went no where... Today I learned there is no point in having traction control, it can't even break the tires loose in the rain... Transmission wines like crazy, Sportstronic shifting is a total joke. The only thing I liked was the radio had bluetooth. MPG's seem to suck, but I lead footed it...

GOD I MISS MY RX-8 SOOOOOOO BAD!

 

Likely sounds like pinion bearing backlash. In which case you gotta pretty much rip apart the rear diff and go through it. At least I would - no point in only resetting the backlash and having something else go out or leak.

 

Anyone care to explain why it would take 32days and 3 attempts (and counting) to rebuild this rear end correctly other that the obvious?

 

Did you take it to a dealer? Sounds like a rookie is rebuilding it.

IIRC, when I did some huge ford pumpkins for training, it was a pain in the *** to get the pinion depth, backlash and rotating torque perfect. Once you got the hang of it, it was okay. Still kind of ghey though.

As a first timer I wouldn't attempt it.

 

Not regular, probably u combined. Inexpensive enough but, bit of a discomfort to substitute. Thats what i would examine first.

 

I brought it to a Aamco that somehow has a good reputation... The other day when iI posted I called HQ and let them know how upset I was over how long it was taking and they gave me a free rental. They said that they were getting a guy from another Aamco to come rebuild it this time.

hoping for the best, but expecting the worse...

 

Test drove it yesterday, couldn't get it to clunk anymore, but there is still a strange "Squeaky/Grinding" noise when ever you apply the brakes... Still in the shop.

 

Do you get your oil changes at Jiffy Lube too?

 

No Team, The shop I brought it too had a good reputation online and 2 friends recommended it to me. Not to mention there was only one other place that would even look at the car in town. My only real other option was the dealer.

 

What's wrong with Jiffy Lube, that is were i get my oil change... lol

 

Got the car back today, everything seems okay for now.

The shop claims (Which I don't really believe a word they say anymore) that a rock somehow got stuck between the rear rotor and the brake pad and every time you apply the brakes it would eat into the rotor, and that this was the problem that I kept bringing it back.

They also managed to loose my lock lug key, which I can not understand how, when both rear wheels do not have a lock lugs, only the front do... And I know they lied about it cause they called and asked me where it was located and I told them in the trunk(This is on the 3rd attempt to fix the car), After I hung up I chuckled a little bit when I remembered the rear doesn't have lock lugs and assumed they would figure it out on their own. Now the key is missing and when I called the shop to ask for it back they said they couldn't find it and used a universal one to take my rear tires off...

All in all this has been a nightmare from the beginning. And with the money I spent I probably could have just gotten Mazda to replace it with a new one in less than half the time this took.

I just hope it's finally over and I can move on. I really need some new tires and a alignment.