I've just installed 3.42 Richmond gears on my Posi 2-series carrier along with all the bearings. It was my first rear end job but I believe my installation was right as the pattern looked really good and the backlash was within specs. I took the car out for break-in and I was really glad to see that it's absolutely dead silent when under load, light or constant throttle or when cornering. Everything feels really tight and smooth, no clunks, but it does whine a bit on coast. To give a scale, it's noisy enough to be heard clearly but when talking to someone the noise is covered.

I admit I focused on having a perfect pattern on the drive side of the teeth, which could explain a slight unbalance but the coast side looked really good too.
I don't mind the gears being noisier than stock (the previous gears were also Richmonds but improperly set by a previous owner) but I want to be sure it's not going to become a time bomb.



Break-in is not over yet, but my question is: would it be acceptable to have some noise during break-in and is there a chance it could get quieter over time? Is coast whine a threat for the integrity of the gearset?

Thanks for the input

Richmond gears even if installed correcty, they will be noisy. They are race gears and it is the way the teeth are cut and lapped in. Motive gears would have been a better choice for a street car

yes richmond gears will be a little more noisier than stock gm gears due to the way they are machined.

what was your backlash at? and what about your pinion depth? also when you tightened the pinion nut did you use a in lb torque wrench to set the drag?

Not sure where you live, as far as temperatures, but you could try and use a heavier weight gear oil. That may help quiet it some.

I hate it too. Mine does that. I have the summit gears. Im assuming those are reboxed richmonds or motive's. I live with it. I have no abnormal wear so I'll stand pat.

Thanks for the replies. I live abroad so there are not many people that are knowledgeable about this.
I don't mind a bit of gear noise but I want to make sure it's due to the gears cut and material, not my installation. I am ok to trade silence for durability as the car is not daily driven. It's perfectly silent when on drive or float though.
Backlash and pinion depth were spot on, after break-in I am going to recheck bearing preload and backlash anyway.
I've used 80W90 gear oil with a bottle of Redline LSD friction modifier/ break-in fluid. I don't know if I could use a thicker oil than that.

I mean you could. But I would run the 80-90 like you are.