Differential Question
 

As everyone knows, since I've been complaining plently about it, I tried to put on the Cobra rear brakes this week. I had to take the diff. cover off, revmove the C-clips, remove the axles. Just now I was putting my FR500 rims on. The car is on jack stands, the parking brake is off, not in gear. I tried to rotate one of the rear tires, it seemed a bit difficult to move but it rotated, but the other rear wheel didn't rotate.

Shouldn't both rear tires rotate when you rotate one in that situation?

I went to rotate the other wheel, it was difficult to rotate also, but I think that was because of the brakes. However, when I rotated this tire, the opposite side tire rotated also. So turn one wheel they both rotate. Turn the other wheel the other wheel doesn't rotate.

Correct me if I'm wrong but isn't that because it's limited slip and not a locker:confused:

Yeah, it's limited slip. But I am very un-educated on the specifics of the differences. I know if it was on open diff. then I wouldn't worry, or if it was a locker/spool I would know something was wrong. But if it's a LSD does that mean it's fine that when I turn one wheel the other turns, and when I turn the other wheel its the only one that turns?

was it the passenger side that turned both

edit actually it really doesn't matter you are fine the wheel the turns without turning the other is driven by the other wheels locking with it so if that one isn't moving that wheel gets no power but can be rotated freely. It's a little more complecated then that but you can get the general idea

Yes it was. I think your on the right track here.

it's like the one way peel in the sixers only one wheel gets power but with the lsd the "power wheel" locks with the other one

So do you think this is fine? I just seem like this is the first time that this has happened that I can rememeber.

I think you are probably fine but I could be wrong cause I don't even pretend to fully understand this stuff but from the little research I did (wikipedia) I think you are fine. I know there are dozens of people on the forum who could answer this better than me though

Thank you for your help regardless. I am just paranoid that I screwed it up, but I think it's ok.

hopefully R3d, spike or one of the other techish guys will jump in and explain

If it's LSD, turning one wheel should turn both. And while turing is hard, it should be excessive. Part of the problem may be that the parking brake out of adjustment (so too tight) or the axle is pushing the rotor into the pads. Try adjusting the brakes (w/ the e-brake lever) and pushing the axles in and out a few times.

I pulled the e-brake a couple of times and it made it easier to turn the wheels. But when I turn the driver's side wheel, only the driver's side wheel turns. When I turn the passenger's side wheel, it turns both. I drove the car this afternoon to bed the brakes, everything seems fine. Is there another way to check if something is wrong?

Do a burn out. :D See if both wheels leave rubber lol.

Haha good prescription.

Haha, I actually thought about that earlier this afternoon. I planned on doing a burnout while I drove it, but kinda forgot. I accelerated pretty had a few times, WOT in first once till 5K, didn't break thoes 295s loose so I called it good then since the girlfriend was in the car with me.

Edit: P.S. The brakes are damn near unbelievable. I swear I stop in 50 feet @ 40mph and less than 100ft @ 60mph. I can't wait to get the rear brakes on and some good set of performance pads.

Yeah the brakes definitely are an awesome upgrade! Every one always talks so great about them and I never knew if it was just over exaggeration or what, you know. Once you drive another car after you get used to the cobra brakes, you'll realize how much your brakes really improved. My moms Mazda 3 brakes used to feel better than mine before the upgrade, but now her brakes seem so shitty haha.

I was thinking on the way home after beding the pads that my car feels like it brakes like everyone elses' car at the autoX. Seems like everyone else has big brembo calipers and rotors. When I drive other people's car and ride along they never feel limited by the brakes, like I did. I will go deeper into the turns now for sure.

That really is the only sure fire way to tell if your posi is toast or not.

Next meet, me vs. you from 70-0 what do you say? I want to know how my upgraded stockers stack up to your almighty cobra setup :D

I noticed a huge difference on my 87 going from 99-04 V6/GT spec with the PBRs to Mach 1 calipers and ebay rotors/pads all around. If I had good tires it would be even better. Really wanting to upgrade my 2K the same way.

The whole thing about one wheels spinning and other not spinning, I'm kind of confused. My understanding is that you either spin the other wheel in the same direction or in the opposite direction. How can you possibly spin one and the other not move? You would have to have the diff gears out for that to be possible. Anyone else agree with that?

I always do the two stripey on the road test when possible to confirm my clutch packs operation.

Mustang GT's are okay at braking, but not even close to as anything with four piston calipers.... When I stomped the brakes on my mom's G35 I felt like my body was going to shoot out the window. that was problably the most awesome feeling ever lol.

I want burnout pics.

As for the Cobra brakes, are they the SVT brakes with a single piston caliper, and a "mini drum" built in to the rotor for the small brake shoes, and with the small brake shoes for the e-brake?

Are they like these?

Lol yeah definitely. I'm interested to see the results.

I'm pretty sure the fronts are dual piston w/ 13" rotors and the rear are single piston with 11.65" rotors.


BTW, I think the differential is fine. I left two long black lines in an empty parking lot just a while ago.