Cuda started making a loud "whining" noise (video)

Posted By: Cudalord

Cuda started making a loud "whining" noise (video) - 05/04/11 05:58 AM

Posting this in the hopes that someone may have experienced this and can give me some tips before I crawl under it this weekend.

Specs:
440, 727 with B&M Shift Kit & TCI BreakaWay torque converter, 3:23 8.75 Sure Grip Rear with MP "Green" Wheel Bearings.

It only happens when I decelerate (let off on the gas and let the car coast). When I give it some gas, the noise goes away, when I let off, it immediately comes back. If I'm going up to speed or on the gas, no issues, only happens when I decelerate. It started off a very low pitched whine, now as you can hear, it is pretty loud.

I attached a video with sound, hopefully you can access it. It appears that the noise is coming somewhere from the center/rear of the car, but I can't be certain as it is pretty loud and high pitched.

Any thoughts or suggestions? Thanks!

Posted By: DoctorDiff

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 06:29 AM

Could be gear noise.

Make sure the pinion nut is tight and you can't rock the yoke in/out/up/down.

Posted By: Keith Black®

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 07:36 AM

sounds like very bad diff noise.. maybe pinion bearings gone.

Posted By: Challenger 1

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 12:53 PM

Quote:

Posting this in the hopes that someone may have experienced this and can give me some tips before I crawl under it this weekend.

Specs:
440, 727 with B&M Shift Kit & TCI BreakaWay torque converter, 3:23 8.75 Sure Grip Rear with MP "Green" Wheel Bearings.

It only happens when I decelerate (let off on the gas and let the car coast). When I give it some gas, the noise goes away, when I let off, it immediately comes back. If I'm going up to speed or on the gas, no issues, only happens when I decelerate. It started off a very low pitched whine, now as you can hear, it is pretty loud.

I attached a video with sound, hopefully you can access it. It appears that the noise is coming somewhere from the center/rear of the car, but I can't be certain as it is pretty loud and high pitched.

Any thoughts or suggestions? Thanks!

If it were me, I'd take a look before I went posting on the internet and then ask questions. Do you want us to fix it too?

Posted By: SixDRacing

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 01:36 PM

ring and pinon has excessive backlash. best thing is to replace the gears. it will not help, at this point, to reset the backlash.

Posted By: Cudalord

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 02:56 PM

I'm sorry, I thought this was a question and answer board. Thanks to you that actually gave some suggestions.

Posted By: Mr.Yuck

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 03:08 PM

Quote:

I'm sorry, I thought this was a question and answer board. Thanks to you that actually gave some suggestions.

yeah I didn't get that reply either. As mentioned sounds like your rear is about done. I'd probably pull the chuck and see how it looks. How/when did this start? was it after a weekend of beating or a gradual thing? 3.23's + heavy car + hard launch = stress on ring/pinion

Posted By: JohnRR

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 03:23 PM

Quote:

Quote:

I'm sorry, I thought this was a question and answer board. Thanks to you that actually gave some suggestions.

yeah I didn't get that reply either. As mentioned sounds like your rear is about done. I'd probably pull the chuck and see how it looks. How/when did this start? was it after a weekend of beating or a gradual thing? 3.23's + heavy car + hard launch = stress on ring/pinion

Also check the MP greenies , they aren't as good as the units Dr. Diff sells ... so I read on the internet ... but that definitely sounds like a rear end noise.

Posted By: Challenger 1

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 03:36 PM

Quote:

I'm sorry, I thought this was a question and answer board. Thanks to you that actually gave some suggestions.

If it were me I would have slid under the car as soon as I heard it and grabbed/checked my U joints and at the same time checked to see if my pinion nut was loose. Then posted my findings asking for advise.

Posted By: Pat_Whalen

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 03:55 PM

Quote:

Quote:

I'm sorry, I thought this was a question and answer board. Thanks to you that actually gave some suggestions.

If it were me I would have slid under the car as soon as I heard it and grabbed/checked my U joints and at the same time checked to see if my pinion nut was loose. Then posted my findings asking for advise.

You do realize that without knowing to begin looking at the u-joints and/or pinion, he'd have a pretty hard time beginning the diagnosis.

To the O/P, I had a very similar noise at one time. Turned out to be my pinion nut losing up on me as other previous posters have mentioned. And don't worry about Challenger. You did a way better job initiating a Q&A topic than most people who would have just said, "Have this annoying noise occurring. What is it?"

Posted By: 1_WILD_RT

Re: Cuda started making a loud "whining" noise (video) - 05/04/11 04:09 PM

FWIW the video is nice but you get no sense of direction/location of where the noise is coming from.. I agree it is probably a loose pinion nut but many years ago I heard a failed convertor make a similar sound & knowing the location would help in diagnosis...

Posted By: RapidRobert

Re: Cuda started making a loud "whining" noise (video) - 05/05/11 12:34 AM

Quote:

Any thoughts or suggestions?

CudaLord your Q was perfectly legitimate. What Doc (& others) said, I'd plan on locating/tossing in another pig. What's the rest of the story on this one, very hi miles? R&P reused? or? Esp as it sounds like it started acting up pretty quick

Posted By: Golden-Arm

Re: Cuda started making a loud "whining" noise (video) - 05/05/11 01:20 AM

sounds more like excessive play in the gears, than it does a bad bearing. check the fluid level yet? if/when you pull it apart, be sure to check the oil, maybe drag a magnet through it, see if you lost any metal, and if so, how much. fwiw, that vid was a good idea, made it easier to hear the whine, instead of just hearing a description.

Posted By: Cudalord

Re: Cuda started making a loud "whining" noise (video) - 05/05/11 05:28 AM

Thanks guys for the tips, it really give me some direction. To answer a few questions:

1. The Video was strictly to give you an idea of the noise pattern, the coming and going of the noise is me decelerating/accelerating, I had no intention of you being able to figure out where it was coming from.

2. The pig was used when I got it, mileage unknown. The first thing I did was check the fluid level and that was last weekend, it was right where it should be and the fluid was clear.

3. This occurred over a period of about 2 weeks, of daily driving, it started out as a very low pitched/intermittent noise.

Posted By: JohnRR

Re: Cuda started making a loud "whining" noise (video) - 05/05/11 01:59 PM

Quote:

Thanks guys for the tips, it really give me some direction. To answer a few questions:

1. The Video was strictly to give you an idea of the noise pattern, the coming and going of the noise is me decelerating/accelerating, I had no intention of you being able to figure out where it was coming from.

2. The pig was used when I got it, mileage unknown. The first thing I did was check the fluid level and that was last weekend, it was right where it should be and the fluid was clear.

3. This occurred over a period of about 2 weeks, of daily driving, it started out as a very low pitched/intermittent noise.

What case number is it ?

Posted By: Cudalord

Re: Cuda started making a loud "whining" noise (video) - 05/05/11 10:38 PM

741 Case, picked it up for 75 bucks a while back, so if that's all it is, that would be awesome. I'll update after the weekend.

Posted By: Cudalord

Re: Cuda started making a loud "whining" noise (video) - 05/07/11 03:36 AM

You guys nailed it. It was the rear diff. I had some time tonight to get the Cuda up on jackstands while I had someone "drive" the car, it was coming from the back of the rearend. I actually got lucky and picked up a pumpkin on CL for cheap.

Posted By: 6PakBee

Re: Cuda started making a loud "whining" noise (video) - 05/07/11 01:16 PM

It would be interesting to know just what failed in the rear end. I have never heard a differential sound like that. Wow.

Posted By: 1_WILD_RT

Re: Cuda started making a loud "whining" noise (video) - 05/07/11 04:12 PM

Quote:

It would be interesting to know just what failed in the rear end. I have never heard a differential sound like that. Wow.

The pinion nut came loose.. Why you accelerate the gears tend to push apart which forces the pinion against its large bearing & the position is relatively normal, but then you let off the gas the gears tend to draw together the the pinion is drawn into the ring gear... If you look it's fairly common to see the carrier have tooth wear marks all around just inboard of where the ring gear rides... I suspect this carrier will show those marks....

Posted By: 6PakBee

Re: Cuda started making a loud "whining" noise (video) - 05/08/11 12:14 AM

Quote:

Quote:

It would be interesting to know just what failed in the rear end. I have never heard a differential sound like that. Wow.

The pinion nut came loose.. Why you accelerate the gears tend to push apart which forces the pinion against its large bearing & the position is relatively normal, but then you let off the gas the gears tend to draw together the the pinion is drawn into the ring gear... If you look it's fairly common to see the carrier have tooth wear marks all around just inboard of where the ring gear rides... I suspect this carrier will show those marks....

I've had the pinion nut loosen on a Dana 60 and it sounded nothing like that. It was more of a 'singing' noise (if that makes any sense) on coast. The actual end play on the pinion before I tightened it up was about 0.080" IIRC.

Posted By: Keith Black®

Re: Cuda started making a loud "whining" noise (video) - 05/08/11 12:50 AM

Quote:

It would be interesting to know just what failed in the rear end. I have never heard a differential sound like that. Wow.

all our taxiis in Australia sound like that