12akid

keep on breaking my diff and i only have headers so what can i upgrade to, thats ez bolt on and hold some power ???

Rx-7Doctor

iTrader: (13)

Drop driving it like a drag car. They don't break easily if driven correctly.

Jeezus

iTrader: (4)

^^^

FIBREMAZ

RX5 diffs are much tougher than 1st Gen Rx7 diffs and can be modified to suit other Mazdas. They have coarser splines and much stronger axles as well

Rx-7Doctor

iTrader: (13)

For those who don't know what a RX-5 is. In the US it was the USDM 1976 Cosmo. And I have only seen 2 here. I in the local area and the other at a wrecking yard that had not been touched up until the time they crushed it.

perfect_circle

85rotarypower

You have to remember the RX-5 "Cosmo's" were VERY rare around here and I would have to kill anyone that tore one apart to make their first gen hold more power just because they didn't know how to drive it right.

Its a little harsh to say it this way, but learn how to drive your car right. The 1st gen diffs have been known to handle up to 250hp without too many problems. Your little worn out 12A with a header is NOT going to break a diff if driven even remotely correctly. Stop dumping the clutch at 7 grand and drive it right.

Rx-7Doctor

iTrader: (13)

And what may I ask is your flag in regards to?

Kentetsu

Probably the fact that this guy has broken so many diffs with his semi-stock setup. I'm pretty rough on my car, and it has over 200,000 miles on it, but I've never developed a problem with my diff. I certainly haven't gone through a few of them...

12akid

im all stock only headers, i broke my diff at the track on the 3rd run, i herd the stock diffs and tranes are super weak, so yea just asking what i can put in it, and yea i only seen one rx5 in my life so thats out the ?

Kentetsu

Drag racing eh? Well, I would have to agree that your technique is suspect. You should look into how you are launching, and improve your methods afterwards. The stock tranny and rear end should be holding up fine for you.

What size/type of tires are you running? Got a pic of the car handy?

12akid

205 on stock 13in rims

REVHED

Is it an open diff? The pins in the spider gears break very easily when spinning one wheel. It has nothing to do with the power.

WELD the bitch. It will last a lot longer if done correctly.

12akid

na is a gsl rearend so it should have lsd, but i just have like 2 gs rearends in my back yard with the punking welded

steve84GS TII

There are only two possible things going on here.......

1.You have unfortunately aquired muliple,poor condition 3rd members and a simple combinaton of milage,neglect and bad luck has spoiled your opinion of the stock 1st gen rearend.

2.Your launch technique is far too aggresive.You only need to launch around 4000rpms,and even then,tirespin will usually cushion most of the abusive 1st gear torque reduction.Aggressive clutch compounds and sticky tires can aggrevate the situation,but its usually the axles shafts that fail first.


That said,I have almost 50K miles of daiy driven use on my 1st gen rearend.In case you dont know,my car is putting down around 300HP and I run an LSD and 245-17" tires out back.I used to go to the track for public drags,but it got old fast and now I just daily drive the car....although I dont baby it! Ive never twisted an axle or broke a ring and pinion.I did pull the pumpkin once,but that was just for a noisy pinion bearing.



Are you changing out the rear input flange when you swapped diffs?
What kind of oil are you running back there?
What exactly is breaking?......ring,pinion,axle shaft?