So I traded my s13 for a 1993 300zx. I've had it for about a week and for some reason yesterday all 4 brakes locked up while I was driving down the road. I had to have the car towed back to my house, I jacked it up and all 4 brakes are locked onto the rotors. I unplugged my abs to see if that was the problem which did nothing, So now I'm thinking maybe my master cylinder push rod needs to be adjusted or just a new master cylinder in general. I checked all the lines, there's no kinks or leaks, Anyone have any ideas? I just got the car and I love it already, and it sucks since I've only driven it about 4 times. If any one has any idea's please let me know Thanks,Pete.

Time for an update, I know longer think my brakes are the problem.. I had the rear in the air and then I started it up and put in first and gave it some gas and the wheels spun. The wheels locked up within a few seconds and then there was some horrible noises coming from underneath, so I turned the car off and I noticed I could turn the wheels by hand just a little bit until they both locked up. So I think something is wrong with my driveshaft causing the wheels to lock up. I know the carrier bearing is gone on it for sure. When the car was drivable I could even hear the driveshaft hit the floor of the car when I drove up hill. I went ahead and picked up a z1 1 piece which I'll be installing tomorrow. I will update the thread again once I uninstall the stock driveshaft tomorrow.

Hmmm...I doubt that a bas center carrier bearing would cause the wheels to lock up. Sound more like a differential problem. If it goes for a few minutes, and then it locks, it sounds like your differential may be low on oil, but I am concerned that the ring and pinion gears may now be useless. Long story short, I'd place my money on the differential being dead and needing replacement.

The way to test this easily is pretty simple. When you are installing the new carrier bearing, you are gonna have to remove the driveshaft. When the drive shaft is out, you should be able to spin the rear wheels (assuming the car is on jack stands). Spin them and listen for noise. If you have LOTS of noise, you probably have a bad diff. You can try adding diff oil, but again, if you are hearing noise, it is probably shot. Withe the car on stands, the wheels should spin very easily and the front joint on the diff shouild spin as well.

Good luck.

leerandallstewart wrote:Hmmm...I doubt that a bas center carrier bearing would cause the wheels to lock up. Sound more like a differential problem. If it goes for a few minutes, and then it locks, it sounds like your differential may be low on oil, but I am concerned that the ring and pinion gears may now be useless. Long story short, I'd place my money on the differential being dead and needing replacement.

The way to test this easily is pretty simple. When you are installing the new carrier bearing, you are gonna have to remove the driveshaft. When the drive shaft is out, you should be able to spin the rear wheels (assuming the car is on jack stands). Spin them and listen for noise. If you have LOTS of noise, you probably have a bad diff. You can try adding diff oil, but again, if you are hearing noise, it is probably shot. Withe the car on stands, the wheels should spin very easily and the front joint on the diff shouild spin as well.

Good luck.

I'll do this as soon as I take the driveshaft off. The car is on jack stands. So once I get the driveshaft out I'll try and spin the wheels and if it doesn't spin still or I hear some bad noises I'll pick up a new diff. Thanks for the info man, I'll update tomorrow on my findings.

Well big update.. got the driveshaft off and and the wheels spin beautifully. No sounds from the diff or anything. The differential is definitely good. Now for some bad news. The carrier bearing is completely gone.. Which is ok since I picked up a z1 1 piece. Now the big problem is the transmission ran out of fluid.. Yeah. It sucks. I drained what fluid was left and there were very small metal shavings on the drain plug, I didn't see any in the fluid that came out. The old driveshaft has some scoring on it from where the transmission rear main seal was dry and the driveshaft was stuck in until I pried on it with a screw driver a few times. So now I'm going to get a new seal and flush the tranny fluid a few times and hope for the best. I really don't want to buy another transmission.