Broken Diff & An Age Old Question
 

Launched it at the track (about 3-4k) tonight and the sweet sound of broken parts rang or clanked. Didn't really read about the diffs on the forum till tonight as mine did work. Not 100% sure as I haven't taken anything apart but trans still engages and same with the clutch but when gradually letting out the clutch and moving forward makes a horrible clanking noise and then moves again, and so on. I have a 1.8L ACT flywheel with the regular pressure plate and the street disc. I guess with this clutch setup especially some guys on here have had the same problem. Anyhow, to get to my question which searching around was somewhat answered; What's the most affordable way to fix the diff and with what setup.

As I understand the 1.8L setups which are 7" instead of the 1.6L 6" are much stronger and would be the better upgrade. Now as I would love an LSD or Torson rear end it's more than I would like dish out right now so I'm on a budget. With the setup you suggest (please if you know) list the best place to get the diff (and/or parts).

** I know of a miata in a local junkyard here that has a production date of 94 and has motor, trans, diff, etc. Not sure if this would be a good donor car.

Thanks In Advance!

All 94+ cars will have the 7" diff... the question is open or torsen.....

M1 1.8's (94-97) are a 4.3 ratio
M2 1.8 99-00 are 4.10 again -- unless it's a 6-spd... then different. (don't know for sure about the 01+... but I assume they are still the 4.1

To swap with 1.6's you need the driveshaft and the half-shafts when you get the diff.... So if you get the stuff out of the wrecker get all of it.

You'll need a "big-ass" socket (28 or 31mm) to break the lock nuts at the end of the shafts. They are 200 ft-lbs or something insane like that... so bring a really, really big braker....

Otherwise, get all of it, and you'll be good to go.

Dave,

Actually, it's the '94-'94 cars that have the 4.1 rear-end; the 4.3 is in the '99+ 6-speed cars.

See here for more: http://members.aol.com/solomiata/Drivetrain.html

I'm on my third diff in one year. (1) 90' open, (2) a somewhat-wonky 93' viscous LSD and (3) a low-mileage 93' viscous diff. If swapping 1.6 diffs, all you need is the pumpkin; you don't need the halfshafts.

The weak link in the old diffs is the ring gear which just shreds and tears up the pinion gear.