Hello to all,

I am trying to solve my whining problem but I need the insight from experts here. I will try to be as clear as possible in order to explain my problem.

Background: Richmond 3.42 on a 2-series carrier, 1988 GM 10-bolt posi, around 500 miles driven since full rebuild, street driven, carefully broken in.

Symptoms: Loud whine when coasting and deceleration, really silent otherwise. Cold/hot no difference.

Observations: as of today, pinion depth ok, no yoke play, pinion bearing preload ok.
Backlash went down to .004" from .009" when installed. Initial assembly was made with stock carrier bearing cap bolts, then replaced by ARP fasteners 100 miles after rebuild. The noise has not grown or diminished after the new bolts but it seems to have affected backlash quite a bit.
Teeth contact pattern wasn't great, both sides are very toe oriented but centered. (At the time of assembly, drive side was perfect and coast was just a tiny bit toe-oriented)
Today, it's exactly like the one on the bottom left:


It's actually interesting that they call it an acceptable pattern. I don't share this point of view.

I'd like to try to get the backlash back within specs, so here is my question: Would getting the backlash back to .010" (engraved value on ring, +.006" from now) alter my pattern in such extent I would need to touch pinion depth (0.035" shim)? I don't get in which proportion they interact with each other. Also, could that adjustment be an answer to my problem or is it a wrong move to take?

Finally, what size of carrier shim would be suitable to increase backlash by .006"?

Thanks for the input.

If you want "quiet", this
is a mistake. You may simply have to learn to live with it.

Take a few .001"s off of the side of the carrier close to the ring gear and move them over to the other side.

I don't mind a bit of whine and I was expecting it but this one is way too loud to be true. Something can be improved, I am sure.
The car had Richmonds before but they were nowhere as loud as that.
Thanks for the reply anyway

Right: Richmond makes those gears for race cars, where the whine doesn't matter. In the interest of optimizing them for the drag race application, they sacrifice some other properties.

My purpose is not to get into the debate whether Richmonds are suitable for street use or not and if they are noisy or quiet. That doesn't help me at all.
They are known to be noisier than stock, that's a fact but they are not supposed to be THAT loud. Not louder-than-my-3"-aftermarket-exhaust type of loud. And absolutely silent in drive.
They are delicate to set up but it can be done and that's advice on how to do it properly that I am asking. I don't mean to be harsh but I am looking for real technical advice here.