Hello everyone,


New here and to 3rd gen world.
Recently purchased a LO3 code 305/M5 car. It survived fairly well and was fun to drive.
The rear however is making a growl/howling noise. It had old lube and dirt caked on the center housing, but someone serviced too late. It was full of oil but a lot of magnetic sludge on magnetic ring inside the pan.
It is a 7.5 10 bolt 3.42LS disc rear, which I believed was original. However after some brake hardware ID issues. I started looking at RPO codes. Car was only optioned with 2.73 or 3.08 open or G80 code LS. So I am assuming this rear came out of a GTA or Z28 option car. It looks original to the under chassis of car.
Could anybody tell me other ID methods so I can order correct bearings?

 

As far as bearings go, all of the 3rd gen 7.5 rear ends used the same ones. The metal is most likely from the Auburn differential, which I highly recommend you replace when you rebuild the rear end.

 

Agreed on both counts.

All the bearings are the same in the 7.5" 10-bolt from about 80 up. (early ones were different but you don't have to worry about that since none of those will bolt up under your car) And, the Auburn is total crap; the stock ones hardly ever are found to be in working condition any more (all have long since wore out and failed), and new ones are still the same crap. They can't be rebuilt and must therefore be $$$replaced$$$ when they fail.

 

Both, thanks for the info.
I really cannot throw 5 bills for a new Eaton LS carrier on this car. Posi is working correctly. Its just the noise. Has to be in the carrier, pinion,axle, or transmission bearings. U joints ruled out.
But the car is worth saving, making road worthy again. Difficult trying to pin where the noise is coming from by myself on jack stands.
Another question, is the ABS ring on ring gear. Since this car wasnt optioned for this, it does nothing?

 

Right; all it does is generate a speed signal, in conjunction with a sensor that senses its teeth go by.