Really strange noise while driving

[nickswhip24]

Unfortunately, I believe this differential has served its time.

I think the oil got really hot due to the broken gears and just until it was solid. That's my best guess. I don't see any signs of leaking anywhere, although the rear obviously gets dirtier than the front

Not sure on that, think the front would work more...i did see a great video on the Mazda awd operation-maybe i can find again...i found the front dirty and rear clean on mine at around 27k.

 

[sm1ke]

Ouch, sorry to see that @Tland4. Been there, done that.. though in my case, there was plenty of fluid, but it was thick with grey and silver particles, and I had just as many metal chunks. Hope you can get this squared away without having to spend too much!

Also, if you've lost rear wheel engagement, be careful accelerating in wet/slippery conditions. The traction control might be too restrictive and force you to limp when you want the car to jump - especially scary when you try to accelerate to merge onto a busy roadway.

 

[Tland4]

Not sure on that, think the front would work more...i did see a great video on the Mazda awd operation-maybe i can find again...i found the front dirty and rear clean on mine at around 27k.

I'm sure the front works harder. I meant that the rear gets dirtier due to not being covered like the front diff is. So if it was leaking, it would've been hard to find.

There were never any signs while the car was parked in the garage.

 

[Tland4]

Ouch, sorry to see that @Tland4. Been there, done that.. though in my case, there was plenty of fluid, but it was thick with grey and silver particles, and I had just as many metal chunks. Hope you can get this squared away without having to spend too much!

Also, if you've lost rear wheel engagement, be careful accelerating in wet/slippery conditions. The traction control might be too restrictive and force you to limp when you want the car to jump - especially scary when you try to accelerate to merge onto a busy roadway.

Found a new rear diff on eBay from a reputable seller for about $1k. Not money I wanted to spend, but could be worse. The car is paid off, and otherwise runs flawlessly, so it's a no-brainer to fix it.

I'm just hoping the dealer will still program it since they're not doing the install.

 

[nickswhip24]

Wouldn't a local transmission shop handle that repair? Could be cheaper than dealer.

 

[Tland4]

Wouldn't a local transmission shop handle that repair? Could be cheaper than dealer.

Probably, but I'm doing it myself. I may just have the dealer do the programming after the job is done.

 

[Tland4]

Got the old one out. Now just waiting for the new one to come in.

Really not too terrible of a job. Took about 2 full hours. The worst part is the lack of clearance around the diffential; so I felt like I was turning a wrench for a full 10 minutes per mounting bolt. The plug above the differential and the two hose connections are also a PITA to get to, but it's definitely doable.

Thankful for a very detailed YouTube video. And thanks all who replied for your feedback.

I also called the dealer today, and the guy I talked to quoted me a full hour for them to program it. Which is fine since I'm saving a ton of money as it is by doing everything else myself.

 

[HyFlyer]

Nice work and I appreciate your updates and photo of the saga.

Do you have a clicky for the YouTube video you watched that was helpful ?

 

[Tland4]

Nice work and I appreciate your updates and photo of the saga.

Do you have a clicky for the YouTube video you watched that was helpful ?

Great question!

Here's the link
Rear Differential Removal Video

He's able to remove each CV axle with the slide hammer. When I attempted the removal with the slide hammer, my CV axles extended through the knuckles without issue, but the diffential ends of the CV axles stayed attached to the diffential. Basically, I stretched the joint out (but did not separate them or, thankfully, tear any boots). So I used a pry bar for its angle, and then put a hammer on the pry bar to drive out the CV axles one at a time.

That was the only issue I had, which was easily resolved.

 

[sinistriel@]

@sinistriel@ Can a replacement rear diff be calibrated or coded with 3rd party tools or does it require Mazda MDS/IDS?

Thanks!

Dealer software for sure, some tools have the ability, one of our Autels has it for some of the models and one of our Bosch did. It will need to be done or you risk poor AWD control and at worst a burned up coupling.

 

[Tland4]

Dealer software for sure, some tools have the ability, one of our Autels has it for some of the models and one of our Bosch did. It will need to be done or you risk poor AWD control and at worst a burned up coupling.

I'm glad you posted this information. I'm about 6 miles from the dealership, and plan on driving straight there when I'm done.

I did have the thought of separating the current coupler and putting it on the new diff (which comes with a new coupler). But with the car being at 100k miles, I think it's wiser to replace the coupler as well.

 

[Tland4]

Finished the swap today. One thing I immediately noticed with the new differential/coupler was that the coupler had only 4 characters (numbers and letters) on it compared to the original which seemingly has a whole line of code--16 characters to be exact. I'm not sure how it would be possible to program the new coupler with essentially no information.

This gave me two choices. I could order a new differential/coupler, or use the original. I decided to use the original. I cleaned it up really well, inspected it thoroughly compared to the new one, cleaned off the original gasket, added some wheel bearing grease to the shaft on the differential as well as the bearing on the coupler, and married the coupler to the new differential using gasket maker. I assume I shouldn't have to do any programming to it whatsoever, but we'll keep a close eye/ear on it for any abnormal dash lights and/or noises.

I also discovered in the original differential that it was a bearing that went bad. I'm going to open it up tomorrow and take a closer look at it since it's effectively trash as there's not a core return option on my eBay differential.

One other small issue with the eBay differential was that the plug for the temperature sensor was slightly different than the OEM sensor. Not a big deal. I just swapped the OEM sensor with the eBay's one.

I'm really glad I did this job myself. I likely saved us several thousand dollars if it went to the dealer for the entire job. Although if I'd checked fluids as often as I should've, I would've saved the cost of the diffential.

Here are some pictures.

The original coupler's programming characters:

The new couplers 4 total characters

Some wheel bearing grease on the new diff's shaft

Installed

The original differential. You can see the single ball, which should be inside of a complete bearing. I'm also assuming that's what I was pulling chunks of--crushed ball bearings.

 

[HyFlyer]

Logical choice on the coupler I'd say . Plus, you have the new coupler on the shelf in case the original ever goes tango uniform. Cross that bridge if you ever get to it.

Now go have a nice steak dinner and bask in the glory of a diy job well researched, planned and executed! (and chronicled haha)

 

[Tland4]

Took the car for a 20mi roundtrip drive this morning. As expected, the noise is gone.

Thanks again for everyone's input. I probably won't post here much, but I do get email notifications from this thread, and I'm sure I'd get a notification for a message as well.

If anyone else decides to take this on, and you have any questions, don't hesitate to reach out!