help me out !
 

Well I was driving my miata the other day and I was getting into second hit about 9 pounds then proceded to hear a loud boom! And I thought a tire blew out and the car was slighty pulling to the left. So I pulled over expecting a blow out and no blow out. Looked underneath the back of my car and the rear differential housing cracked. So anyone know where I should go to fix this or what I should do about it ( swap to a 1.8 rear diff. ) ? Running about 280hp right now incase this helps. All info helps a lot so lmk what's. Up my fellow miata lovers. Thanks

It's toast. Time for a new rearend.

This is gonna be a short thread, but.....

Search and read up on it, lots and lots of info on the site. If your mechanically inclined enough to boost it, shouldn't be a problem replacing the diff on your own.

You can replace with a 1.6 diff on the cheap and quick, but likely have the same result in a matter of time- or you can upgrade to a 1.8/Torsen though that route is a bit more expensive. My car came with a Torsen so I've done little reading on the matter, but if you go that route you'll likely need axles, not just the diff unit.

You can scavenge the classifieds here, at clubroadster.net, miata.net, planetmiata salvage, partsgroup.com, craigslist, etc... If you have a junkyard close by, might be cheaper. Torsens are a fairly high dollar/high demand item (relatively speaking in the Miata world), as opposed to stock 1.6 units which are the opposite.



I'll let the regulars come and mop this up, but if I were you I'd go make an intro thread in the meet/greet, edit your profile to include your location, and put car info in your sig (yr, mods, and what have you). Not only is that information crucial come advice time; but it's likely a forum rule and definitely common practice and convenient for yourself and others.

Word of advice, a huge wealth of knowledge on here is there for the taking. But this forum and its members have been around for quite some time and as you would imagine lose interest in repeating the same advice over and over. Your issue is a common one (most are on cars this age) so read up on it and feel free to ask for help should you encounter a snag after you've researched the solution. Mind you there are many new members that come and post immediately and are met with several humorous replies, you will need to be a little patient until you find the thread which discusses and addresses your issue but surely its there. That in it of itself is the main reason why the forum tries to weed out repetitive discussions; as it makes it harder for everyone to access the useful information.

GL

Toast is toast....not rebuildable - time to replace it.

94+ or bust.

True statement...minus base model of course. ;)

The nose on the 1.8 rear end sticks out farther than the nose on the 1.6 rear end, you'll need the shorter 1.8 driveshaft when you upgrade to the 1.8 rear end. You will also be looking for the speedo gear assembly from the 1.8 that the rear end comes out of. You should already know where it is if you're turbo. In case you don't, it comes out of the rear of the transmission on the passenger's side, the speedo cable is secured by a black plastic finger-tight cap (use channellocks if necessary to get it loose) The speedo gear assembly is then held in place by only a 10mm bolt. Remove bolt and the assy should slide out with no/light force. Then slide it into your current transmission and reattach the speedo cable. If you get the rear end out of a 99 or later donor car, you'll need to source your own speedo gear as those use an electronic sending unit. If you get lucky, maybe you'll find a rear end with the same ratio as your current rear end, and you won't have to mess with the speedo gear.

But you will have to replace the driveshaft. Chances are: if your rear end has failed, you've already upgraded your clutch.

In which case:

Chances are your transmission is the next weak link.

Yeah I just had a act stage 3 installed about 30k ago still very very strong. Well as we can see lol