S_Johnson

So I bought a new yukon duragrip posi, and summit racing gears.

Had them installed by a local (highly recommended) transmission shop.

It whined really bad the first time I drove it, if there was any load on the diff (you are pressing on the gas), it went away (mostly) if there was drag on the diff (letting off the gas).

I took it back, and they tore it down and re-checked the gear pattern, etc... He ended up changing the carrier shims a bit.

Now, it just flat out whines, no change really depending on load, but it "sounds better" if that makes any sense. It doesn't seem to grind, or have to much play or anything.

They are having me drive it for a while, and let the gears break in, and see if it changes/goes away.

My question is, has anyone ever had new gears (that were installed properly) whine, and go away?

I know the default answer is: "They are installed wrong," but this guy knows his stuff, and he tripple checked all the clearances.

It should also be stated that all the bearings are new, including the races, etc...

vortec350s10

I set up my 10 bolt with new Richmonds, and it whined when you were barely on the throttle. Figured I had the pinion depth set a little off. Drove it that way for probably 10k miles, the whine never changed at all. When I broke my pinion, I slapped in a used set of OEM gears and simply left the original bearing and shims on the pinion and slapped it in. I was only planning on running it for a couple weeks so I didn't care. They didn't whine one bit, and somewhere on here I read that 9/10 7.5 10 bolts will work the best with a certain shim. I believe .030" if I remember right. I would expect the pinion depth might not be correct. For the guy doing the setup, changing shims on the side of the carrier is easy, but redoing the pinion shim would be a pain. Are you sure he isn't trying to avoid messing with the pinion? I wouldn't plan on the whine improving, just keep trying till someone gets it right. I thought I would get used to it, but it was just as annoying two years later for me. Hope this helps.

sofakingdom

iTrader: (1)

It's .035" actually.

I have NEVER taken apart one of these rears from the factory, NOT ONE, and found ANYTHING BUT a .035" shim in it. Since the purpose of the shims is to adjust the HOUSING (which has lots of random variation) to the gears (which are very precise), that would appear to indicate that either (a) the factory managed to get at least that one aspect of machining the housings reasonably consistent; or (b) that the guy that sets up rears in the rear plant followed the BOM to the letter without doing any trial fitting or measurement at all. Either way, since the factory has apparently produced MILLIONS of 10-bolts with .035" shims in them and NONE with any other size, we out here can probably put .035" shims in them too, and they'll work just the same for us.

That DOESN'T work for Richmond drag racing gears, which have NO BUSINESS WHATSOEVER in any car that EVER sees street duty. They are specifically designed for drag strip use, such that their metal is soft and will flex to absorb the shock of a hard launch without shattering the teeth, and the tooth angle and whatnot is optimized for strength not long mileage; they don't last well as a result. Might be the best thing you can use for a single-purpose strip-only car, but are a BIG mistake for ANYTHING ELSE.

big gear head

I've said this many times, and here it goes again. You get what you pay for. The cheap Summit gears will whine MOST OF THE TIME. Some times someone gets lucky and gets a set that are quiet, but these bargain brand gears are just not made to be quiet. ALWAYS GET GOOD QUALITY PARTS! Cutting corners always comes back to haunt you. If you want it to be quiet then get a set of US Gear, Yukon, Motive Performance or the better Richmond gears. Even Richmond has a cheap set of gears, and they will make noise too.