Blown diff or, not blown diff?
 

the other night i was doing a few doughnuts in the rx7, not for long at all and i was keeping revs under 5k all the time, while doing em i didnt hear noises,
but when i stoped and took off agian, there was a grinding noise coming from the rear end when ever i acclerated. but the car still drove normaly. but i furgered it could only be the diff making that sort of noise.

so 2day i had the car jaked up ready to rip apart the diff, when i thought maybe i'll i just change the oil, see if there is many metal peices in it but i go ahead a rip it all apart.

so i drained the oil and there only 2 or 3 very small pieces that came out, but it was prety metalicy and grey. so i filled it up agian with some new fresh gear oil. took it for a spin and no more grinding, i all drove it for about 1/2 hour 2night and agian no grinding and its driving normally.

could it have just picked up some metal scraps in the doughnut process? and that was making it grind? or cus the diff still have broken parts inside??
i figured if a gear was going to snap and fall inside it was either contiunue to grind, lock up the difff, or only power one wheel which would make the car go one way? :confused: :confused:

i hope this is one of them problems that fix emself
here one day, hopfuly gone the next

You could have broken a tooth off a gear or something. We had a truck here on the base I work at make noises from the rear. Just little clunking sounds at random. It became consistant until finally it started running like a bag of hammers. When the rear was opened up, one of the gears came out in like 30 pieces.