Allright, I just finished installing my new rear-end in my car about a week ago. I took it for a drive today and yesterday, and there is an incredibly loud whine coming from either the rear-end or the drive shaft. It doesn't happen if there isn't any load on the car, but if there is, it's really loud. I'm talking about the same volume as having a noisy gear drive right next to your head. It's that loud.

It gets noisier as I increase speed, but not neccesarily RPMs. In first gear it's not there at all, and in second it's not very noticable. Fifth gear on the highway is when it's loudest. It's fine if I just coast and it sounds normal, but if I give it even the slightest amount of gas, it does the loud whining again.

The new rear-end has Motive 3.73 gears and an aftermarket Auburn posi. Now, I know aftermarket gears can sometimes whine and be loud, but I've never heard any like this, it's just unbearable.

I was wondering if anyone knows what this is? Could the driveshaft be in 180* backwards? At first this was my thinking, but I don't really feel any abnormal vibrations, so I figured it wasn't. I'm not really sure where to go to fix this problem, if anyone has any suggestions, please let me know.

-Thanks, Brandon

 

well, i was test driving a f-150 with a shop teacher, It didnt make a nouse turning etc, nly when hit the gas he presumed it was a pinion bearing in the rearend but ut wouldnt make sense if its brand new

 

I'm gonna be pretty pissed if it's a pinion bearing. I just bought this rear-end off one of the mods on this board. It was brand new other then being assembled and being driven around the block a few times.....

I just flipped my driveshaft 180*, and I'm about to go test drive the car real quick, I'll let you guys know if the noise is still there.

 

Well, no change whatsoever. It's still there, and just as loud.

 

Anyone know what it could be? I'm really hoping it's not a pinion bearing.

 

unfortunately it sounds to me like either a bearing or improper gear set-up.
- and for future reference, there is no backward/180 out for a driveshaft. the shaft is balanced by itself. You could even knock the yoke off the front and switch ends if you wanted....

 

You could put her up on jack stands and run it to try to identify where the noise is coming from. First make sure its not coming from the tranny. Sometimes the way the noise is transmitted its hard to tell!

Note, it will probably sound even worse on stands!

Next, while its on stands. You can rotate the driveshaft by hand and listen for some scraping noises. If it sounds like somone is dragging a cement block down your driveway that would be bad.

I've never had aftermarket gears, but like you said, I've heard they can be loud.

First see if you can isolate the problem.

 

I doubt it's tranny noise. The car ran fine before this, I put this rear-end in and the noise started. I didn't touch the tranny whatsoever, only the driveshaft and rear-end.

I can't actually run the car on jackstands. For some reason when the suspension is uncompressed in the rear, the driveshaft hits my I-pipe just slightly. It doesn't do it while I'm just driveing normally, only on jackstands. That's not the problem though so I don't wanna focus on that.

Aftermarket gears can indeed be loud, but this is just unbearable. I've been in plenty of cars with aftermarket gears, and there's a slight whining, but nothing this bad.

I'm still kinda pissed that the pinion bearing is a possibility.... I just bought this from a mod on this board who said it was virtually new with only a few miles on it. It looked it, but how could a pinion bearing possibly go bad so quickly!?!?!?!?

 

lift it up and support it from the axle so the suspension is loading then try it.

 

Sorry to say but it is the pinion bearing....mine does it too....had a shop look at it and they said the races in the main bearing went bad on mine....

MOST HORRIBLE SOUND EVER!!!! I have a sub in my car so I turn the stereo up everytime I drive but Ill either just buy the bearing or the whole rebuild kit this week....im thinkin just the bearing for now...

Mine appeared after I installed a new transmission with a VIOLENT shift kit...

 

...so you're risking tashing the diff housing, the pinion gear and possibly more the longer you drive? If a bearings out, don't drive it until you fix it.

- as far as running it on stands, as stated, jack it up and put the stands under tha axle tubes. That way when you let it down the suspension is still under normal load.

 

you can screw up pinion bearings in some stock 10 blot diffs by over tightening the tq arm bolts ..
sometimes new bearings take a dump no ones fault it just happens..
new gears can be bad it happens
setup could b off a bit to
I have setup more than 300 rears and I have seen a ton of crazy stuff happen

 

Can you really do it by overtightening the TQ arm bolts? If so, I know mine were tightened a LOT. I basically just had 2 wrenches on it and tightened it until it wouldn't anymore. My 10 bolt isn't really stock, but the housing/axle tubes, etc are. The Internals aren't though, do you think I should stil try looseing the torque arm a little?

Also, I was talking to the person I bought the rear-end from, and he said that it could possibly be the backlash as opposed to the pinion bearing. I was told that usually if the pinion bearing is bad, it'll vibrate too, bu it could just howl on occasoin.

I think I'll try loosening up the torque arm a little and then if that doesn't work I'll move on to backlash and then pinion bearings/races.

 

Rear-end gear whine is a sure sign of incorrect pinion depth. You say you installed them yourself? What method did you use to set the pinion depth? Did you use a pinion depth gauge, or the backyard mechanic "paint" method or both (recommended)? Personally I use only the paint method as I don't have pinion depth gauge. Just be sure that you get a nice even contact pattern on all of the teeth. Hopefully you didn't just put the new gears in and not check anything at all......or whoever installed them to begin with. Also, overtightening the ring gear to the carrier can cause distortion.

 

No, I didn't install them myself. I bought the rear-end used from someone on this board.

 

I understand the problem......I did this before the guy told me the problem...sometimes you just gotta drive down the street though...ill get to it when I get to it

 

I replaced the pinion bearing in my rear end - wasn't that big of a deal really, unless there are two or something - I replaced the one in the front of the diff, behind the pinion nut. Mine whined terribly, and greater whine at greater speeds. I removed the driveshaft from the rear only, removed the pinion nut, removed old bearing, installed new one with new crush sleeve, installed new pinion nut, installed drive shaft. Took like 1 hour in the driveway with a jack.

I have to ask - what does a torque arm bolt have to do with the pinion bearing? The torque arm bolt doesn't actually go inside the diff housing at all - otherwise you'd leak diff fluid when removing them. I'm lost on this one.

 

...you only replaced the outer pinion bearing, there's another one pressed the pinion that sits right against the gear, inside the case.
- The problem with 10-bolts is case flex. Over tightening the tq arm could theoretically crush the case down, thus throwing the pre-load and other settings off. - That said, I've in-and-out'ed mine several times and I just hammer away with an impact...never had any issues.

 

OK - I'll buy that.

 

Did you fix it? I'm curious what the end result was.

-- Joe

 

yes now i neeed to knoe the outcome., could somoen please do a fallow up,.i want to know realy bad,.,.my rear does the same thing start3ed after i did a lil doughnut in the desert.,.,mine has wined for the past 3k miles and if ya barly touch the gas it does it but if i ket off it sounds fine,..,.,so please i would like to know step fer step what it took and how hard it was to do,.,.ive been told many times its just easier to replace the rear end with another.,,.but ide love to fix this prob myself and rin my girl and i of that horrible whinning sound we got a good car and i want it to sound that way again

 

I wonder if he ever checked the fluid level after installing it?

 

He must have. He seemed like a good kid when he picked it up.

I bought the rear end off a buddy for my '91, and drove it around the parking lot a little before I decided to buy a vette (whole situation happened within like 3 weeks time). My buddy assures me it was fine and made no noise. When the kid called me after he installed it and said he made horrid noise, I told him to check the backlash and let me know what happens. (pattern looked good with grease, but I never measured it). I never heard back from him.. Oh well.

I'd like to know what it was. He said it didn't vibe which, pinion bearings almost always do. My richmonds used to whine like a school bus, but he assured me this is MUCH louder.

-- Joe

 

so if it was my pinion bearing in there it would vibrate,. and if it is just back lash then its it will wine

 

Mine was fixed this week......mine wined like hell....it was the bearing and the gears.....the bearing cap/screw exploded off causing the gears to chip n scratch and the bearing to leak like mad......660 bucks later I have a new 3.73 quality gear set and a completly rebuilt rear end and the car drives awsome...and quiet...best money ive ever spent on this car......well the tranny chirps 3rd now too...so that was a well spend 690 haha

 

660? wow i just cant afford that right now,.what do ya mean the bearing cap/screw exploded ????cant i just fix it myself??

 

might also need trans fluid

 

Man, I've had that whine in my bird for a while untill that one dreaded day. Crack!! Crack!! Crack!!!
It sounded like the muffler fell off and dragged on the ground. I got mad at the exhaust shop. Then I drove it a bit and the pass side tire was going up and down with horrible noise.
I really hope you don't have this problem. So, I would have it checked out ASAP before its too late.