I have searched and searched this board and, while I have found a lot of info, I haven't gotten the straight answer I was searching for. Here is my situation. I just got my car back from a 2.73 to 3.42 swap. I kept my stock Auburn 2-series posi carrier and had a "thick" (to accommodate the 2-series) 3.42 Yukon ring and pinion put in w/ all new bearings. The guy that put it in drove the car yesterday and said it was whining on acceleration. He took it back apart and checked everything, made a few minor adjustments and put it back together. He drove it today and said it sounded OK to him. I drove it home, and on the way noticed a little bit of whine in the rear end. It is a CONSTANT whine (maybe a little worse on acceleration), but coasting or deceleration between 40-50 mph it is there. It is very minimal. It kinda sounds like some little cars w/ manual tranny when they are in reverse (if you know what I'm talking about), but much quieter. Is this to be expected from these aftermarket gears? Will it get better with time possibly? Should I take it back and have them check it again? I don't want to sound like an idiot here, but I just don't know what to expect out of this new rear end. I've never had a new rear end other than OEM before. Thanks in advance for all your help! P.S. This is the first time I have driven the car since I had my 355 w/ full exhaust swapped in along with rebuilt tranny w/ Dana's modified Transgo kit. That along with the new gears has turned this thing into a BEAST! I love it!

Anybody?

What brand is Yukon gears? I've only ran GM's before and building one now. My present 3.73 is the only one that made a noise and only at around 30 mph. But I do not know the history of it before I pulled it out of a car I bought for parts.

gc, I went almost the same route with my 96 except I chose a 3.73 Yukon set to replace my 2.73OE's. I too have a small but noticeable whine. I helped install, it's within spec with nice gear mesh pattern.

Perhaps these Yukon aftermarket parts are prone to noise production? That seems to be the case with mine set as well.

I had a 3.70 Yukon set in my 9 bolt and did not have any gear noise. I do not believe the gears "should" make any noise. But then my wife's 05 Mustang has had rear gear noise from day 1. Not much, but noticable. It probably won't get better with wear and once there's a 1-200 miles on the set I don't think you'll have any luck re-setting them up. Damage is done by that point. Hey if it's not that bad I guess you'll have to live with it but the gears shouldn't whine at that modest ratio. IMO.

My mechanic and I pulled the cover off this afternoon and looked hard at the gears. They seem set up just right. The pattern is perfect. Everything looks right. I guess it might just be something I'll have to live with. BTW it has a little over 20 miles on it so far.

The only thing I could think of was pinion depth, but if the pattern is right, it should be right, too. It was within specs when installed.

This is not a major noise, but it is there. It is barely noticeable. I just didn't want to tear up a brand new rear end.

Thanks for the replies. Keep 'em coming.

Yukon IS the brand. http://www.yukongear.com

(The music on their home page is REALLY annoying)

I assume you were thinking I took gears out of a GMC Yukon? Sorry for the confusion.

No I didn't think that....lol

I just did not know that Yukon was the manufacturer.

i just finished putting 4.10's in my car and it doesn't make any noise. i always heard if its whining then the backlash isn't right.

Typically that means the backlash is set too tight.
It might wear in and you'll be fine. Or put in thicker gear oil to shut it up.

If you are not running GM Axle lube in the axle, you could try it. It eliminated a minor, but noticable and annoying whine from my Richmond Gear 3.73:1 gearset when I replaced whatever I was using (I forget now) with the GM lube.
Bill

hey i just replaced my gears to 3.73 and posi traction, now my speedometer is all meesed up, and when im doing 60mph it says 90 and once it gets to 110mph the computer stops sending gas.

what part do you need to calibrate the speedometer

anybody?

'Cmon tilerob, classic hijack! LOL ... kidding. I don't mind. I think I've got my answers anyway.

You need to change your speedo gears. There are 2. One is the "drive" gear and one is the "driven" gear. You need to know your new gear ratio along with tire size to find the right tooth combo. Do a search for "speedo gears" and you should find many threads with the info you are looking for. The drive gear is easy to change. The driven gear requires pulling the tail off your tranny (but you don't have to actually pull the whole tranny). I had a shop do mine and it took no time at all.

Welcome to TGO. The most powerful tool on this site is the search button. Have fun and learn a lot!

Rear end went back together today w/ new shims from Randy's Ring & Pinion. Pattern was dead-on perfect. The whine is still there in a pull !!

They are taking it apart once more and, if it us unfixable, I guess I'll just have to live with it.

I asked them if they checked the pinion depth with a gauge, and they said they didn't have a pinion-depth gauge. So ... how do you determine the pinion depth, I asked ... they said if the pattern is good, there shouldn't be any noise. Does this sound right?

Yea, pinion depth gauges are rare. most shops don't have/use them. They just go by the pattern. If it's off, and you need to change the depth, you just do it. Measuring it isn't too important.

Sounds like a plan.

as I just went through this. The pattern is dead on but I cannot really testify to any noise as the rear is not in the car yet. I have heard some brand gears simply are not as quiet as others especially GM gears. I have only ran GM so far and they have been quiet. 2.73, 3.08, 3.23, 3.73 and now my set up with 3.42's [to be determined to noise level]

I know it's a bitch to do something that you want to improve and it turns out to be a pain in the a$$ but that's the way it is sometimes. Ask me how I know..............