Chunk from differential, track day on Monday
 

Found a pretty big chunk on my diff's drain plug.

Last diff fluid flush was about 6-7 months ago, 10-11 autocross events and 3 track days since. Not sure this piece broke after the first event or the last event 2 weeks ago. Haven't noticed a change in driveability.

Do I go to the last track day of the year on Monday, hope nothing happens knowing that I may need to pay for a tow back and then get it looked at by an expert after... Or do I just call it a season and see if I can get a refund?

For some reason I cant attach or insert the photos, here are a few:
http://i1379.photobucket.com/albums/...pshkgbel87.jpg
http://i1379.photobucket.com/albums/...psloeqqbwi.jpg
http://i1379.photobucket.com/albums/...psfbscfnzi.jpg

If this post doesn't belong in this section, please move it.

Well, I learned that I think I have a Tochigi Fuji LSD and not a Torsen like I assumed.

The tab seems to be a cone clutch/clutch pack part and from what I have found there should be 8. Quite a few people have reported breaking a tab and have been driving/auto'xing and tracking their cars.

Mattesa on miata.net:
"Yup, my piece looked just like that too. I track the car and drive through snow (sideways at almost walking speed.. open diff definitely cannot do this) and can confidently say that my diff works just fine despite the tab falling out."

Hopefully I make it through Monday and am able to drive it to a shop to get it fixed/rebuilt before next year :eek:

Future reference for anyone else that finds a similar looking tab from there diff:
Details on rebuilding the Tochigi Fuji? - MX-5 Miata Forum
Something fell out of my LSD diff. What is it? - MX-5 Miata Forum
The Used Parts Gamble... Lsd Repair? - MX-5 / Roadster Forum - MX5Nutz Forum

I had a piece that size come out of my TF. I autoX'ed and tracked it heavily (30+ events per year) for another 2 1/2 years, no issues.
I did purchase a Torsen when an inexpensive one came up locally, just in case. It sat in my garage for 2 years before I put it in.

I had the exact same thing happen.

Most people report that everything is fine and there's nothing to worry about, but my diff has developed a loud creaking noise when making sharp-ish turns and accelerating at all (such as pulling out of a parking space), or whenever I apply a decent amount of throttle on just about any turn on the street, which happens often because that's why I chose to daily drive a Miata.

I too bought a cheap Torsen months ago just in case my diff decides to die altogether. I'll install it this winter when I find a spare carrier and order some seals and such.

I did take it to the track once after it had 2 teeth show up on the drain plug on separate fluid changes, but it was my first and only:facepalm: trackday, so I likely wasn't putting much stress on the car as compared to someone with real seat time.

Thanks for the info guys!

The car was OK yesterday (or so I think).

Looks like I need to start looking for a cheap LSD as a backup as well.

Is it true that once all 8 of those metal tabs break, the diff will function as an open diff? That way if it does break before getting swapped, I can still drive it home as opposed to paying for a tow.

I don't know for sure, but the tabs breaking off is a good reason to be concerned. If one of the tabs makes its way to the ring and pinion before finding the magnet...I don't see a positive outcome

that looks like piece of a clutch plate

Even if it wasnt breaking or making bad noises I would replace the TomagachiFukyomama diff as soon as you could. ANd yeah, even if you loose all the tabs it'll still work as an open. Heck even with all the tabs its probably already working as an open right now.

Subtle racism makes you look really, really cool, Leafy.

? Just because I can't spell tomishimfushim or whatever it is?

Well you could like read, since Tochigi-Fuji was posted in post #2... or you could be a shitlord.

We all know which option you love to choose.

e: Just to make myself absolutely crystal clear, you had plenty of outs, but you chose the racist shitlord one. Like abbreviating it to "TF", looking up the name, calling it "the fake torsen, but is actually a weird clutch type"; however, you went, "alright, time to type out TomagachiFukyomama" and clicked "Reply".

Exactly, lea------.

Happy to report that my car made it all the way to 145,000 miles being tracked 4-5 times a year all 7 years that I had it. And the diff was still working fine as far as I could tell.

:winner:

Fast forward to yesterday, only did the one track day on October 12th and barely any street driving after that.

https://www.miataturbo.net/attachmen...ine=1457291360

Brings the tally up to 2, should be 6 more remaining :hsugh:

https://www.miataturbo.net/attachmen...ine=1457291360

Many people seem to think these diffs aren't so bad and you can still abuse them and everything will be fine when they have spit out bits of clutch plates or whatever.

These people are mistaken. It is just a matter of luck.

When I bought the car I changed the oil and there are small slivers.

One year later I got a whole chunk like you did.

A few weeks ago, with the wife in the car, I took off from a stoplight in a normal, wife is in the car manner. Sounded like the differential exploded and instantly made terrible grinding noise proportional to speed. I started laughing and the wife thought I went mad. I was laughing because I was glad I had a spare Torsen on the shelf.

Drain plug:

https://www.miataturbo.net/attachmen...ine=1457309779


Found these inside the case:

https://www.miataturbo.net/attachmen...ine=1457309779


There were more metal bits than this. The oil looked like metallic gunmetal paint.

I had a Torsen on the shelf, and replacing this on my DD unexpectedly was a crappy inconvenience. On the upside, I can tell you that T-F diff was not doing its job and the Torsen transfers torque WAY better, and I can tell you this just from street driving.

Do yourself a favor, go buy a Torsen ASAP. Swap it in when it is convenient. Never look back.

Hope this encourages you to take action sooner rather than later. If this failure were to happen on track I'm sure it would be pretty unsafe.

Tochigi-Fuji failure

Agreed, I know I need to get a Torsen ASAP. Tight budget and other more broken things are just ahead on the list.

So what exactly happened when it sounded like it exploded? Was the car still drive-able or did you need to tow it home?

I heard a brief tire chirp the instant the failure happened, so I think the chunks got caught in the ring and pinion and locked up the rear end for a very short period of time.

The car was driveable...in the loosest sense of the term. After pulling into a parking lot and very slowly coasting, I think the drain plug grabbed the larger pieces. It only happened about 1/2 mile from home, so the drive back was short, thankfully.

After the incident, any time the car was rolling it sounded like a big in-sink garbage disposal crushing ice or something.

It didn't sound pretty, and if it were a longer drive home I'm sure another chunk would have made its way into the wrong spot and do more bad things. There were a lot of large chunks in the oil.

I agree with Dustin. if you are tracking and find a diff chip you need to do something about it. this happen to me years ago when I was tracking a different car ALOT. the diff was chipped, and would make a little noise on slow, hard turns, like turning around in a parking lot. I said f-it and did a track event and the diff exploded in a slight high speed turn @ about 110 mph. luckily I shed most of the speed in the spin and I was not hurt but the car was totaled. it could've been bad but since I nosed into the concrete wall the front end took all the force. crumple zones are good. it took track workers a long time to clean up all parts, and bet we lost a hour or more of track time due to the accident. for those who are pushing it on sticky tires and turbos you can not fuck around with this stuff. if you can't pay to fix it you should not be on track. shit happens, we all get that but don't let that mindset be an excuse for negligence when it comes to maintenance of an obvious problem. those of you who have done this stuff for a long time will agree.. it sucks to loose a car you've worked on for years over something you will look back on and say "I should've known better".