67_CAM_LS1

Hello all! I am seeking knowledge! I have a 67 camaro with a ls2 (procharged) with a t56 and 12 bolt rear end. Symptoms are I have a loud whining/ grinding noise coming from the rear end. It really only occurs at about 60-65mph and only when coasting. Not when decelerating. If I push the clutch in or put the car in neutral that's when the noises are heard. And when you get below 60 mph the noise goes away. You can also hear them at what I call the sweet spot (the point where you aren't accel or decel but right in the middle. Now I have replaced the gears with new ones twice as we'll as all the bearings twice but I still have the same issue. I have the pinion per load at about 20in lbs and back lash at .007. These are both within spec from both Richmond and Randy's ring and pinion. I have spoken with both of then to include Auburn gears and no one has any idea! Again when I say loud I mean it sounds like the rear end is going to explode. It's not a whine like backlash is a little off.

Also went through the transmission and nothing out of the ordinary there.

Now I did just take my drive shaft to a balancing shop and they said the pinion end was not square by .040. Not sure if this would have anything to do with it but to make sure I am having a new one made.

Finally the rear end did get hot on the first set of gears due to the ring being too close to the pinion. The oil smelled like death then it seems like after I readjusted everything and added new fluid this noise issue began!

I appreciate all the help and advice!

PowerAdder

I've got the same noise in my Nova, but its on deceleration. Basically our noises are occuring when bearings are loaded, or unloaded and deflecting. And changing the space between the gears causeing the noise, or the bearings are themselves making the noise. In your case after the heated rear end and bad fuild I would think your bearings are damaged/worn. I know my bearings are worn, this rear end has been threw hell.

67_CAM_LS1

Yeah, thats what I thought so I purchased and installed new gears, pinion and carrier bearings but still the same thing. Also it is only seems to be making noise once the rear gets to operating temp or at least it is more noticeable.

So I just pulled the whole rear end out of the car this past weekend to reset/recheck everything for the literally the 10th time! Noticed there are fine brass (i think) shavings in the oil but they are very fine.

All measurements were in spec but I went ahead and replace the outer pinion bearing and race and because I couldn't see its condition behind the seal. Nothing wrong there either.

Put everything back together and to spec again and took for a test drive.

The noise is still there!!!

I would have already purchased a new rear end but this is a GM 1967 12 Bolt with the original radius rod attached, not to mention it has a heidts 4 link setup welded on it so it would be like throwing away $4000-$5000 by starting over.

I am almost thinking that one of my carrier caps is cracked and when it heats up it is allowing the carrier to shift just enough flex to cause the gears to grind. I checked the caps when I had it apart but didn't see anything.

PowerAdder

What are you using to test backlash?

67_CAM_LS1

Magnetic base dial indicator.

sicksspeed

iTrader: (2)

What if you get someone with axle experience to go for a ride just for some input. Maybe you have normal noise being transferred and making it sound worse than it is. What I mean is the mounting of the axle is not isolating the sounds. Like rubber bushings soft, good isolation and neopreen (or however it's spelled) hard and transfers. Just a thought.

67_CAM_LS1

Yeah, that had crossed my mind a couple times! But unfortunately I don't know anyone local that has been recommended or that I have been able to find myself. Randy's Ring and Pinion is about 100 miles away (all day event and they aren't open on weekends) but unfortunately I don't trust the car (rear end) enough to drive there. I know I can trailer it but still will be a all day event. I will try to find a reputable rear end shop and see what they say.

DisasterpeaceWS6

iTrader: (1)

I have the same noise also. I think the noise is always there accel and decel its just the exhaust sound is louder so you cant hear it while the RPM is over like 1500.