Helo everyone, I have a question for people with MU3 trans and G85 limited slip differentials. I recently had my 07 colbalt ss in the air to do an oil change and was also looking for the cause of a pop noise under load from the drivetrain when I noticed that both front tires do not spin together. Has anyone else noticed there posi operation and know if both front tires should be locked together?

 

Its not a locked unit. There is supposed to be some variation in wheel speed.

Check your CVs and control arm bushings for the popping.

 

FWD car can't have its wheels "locked together" or you wouldn't be able to drive it! Even RWD cars have to be able to have the wheels turn a different speeds to go around corners or it'd cup the HELL out of the raer tires!

 

Hey thanks for the quick reply. I already torqued the suspension, checked trans and engine mounts, felt for play in drive axles. So is the limited slip in this thing a locker then, i cant find any info on it.

 

It's because it's in the air. Either wheel will spin in the air, this was covered not too long ago.

 

I realize this thanks, I didn't know if this was a spring loaded clutch style "limited slip" that would turn both wheels by hand or if its a locker and need wheel speed variation before engagement.

 

In a way, it's an automatic locker. open until too much stin then locks together

 

So i did a locker engagement test that is used on trucks. I hold one wheel from moving and start the car in first gear let it run, it had no engagement, I gave it gas and increased speed and still no engagement. Any thoughts???

 

It's a torsen style dif I believe. It will never lock the wheels together, ever. It just splits the torque a certain percentages. Once you push it to hard, it'll just spin one tire.

 

When i have my redline on the lift you can spin one rim and the other will spin too.

 

I am now driving on my 5th LSD. GRRR!

 

What was the failure involved with it and how much does that cost, in know the MU3 requires special tools that the dealers dont get unless they buy them.