Hello Folks;
I need some help on a Noisy Rearend (no...not my mother-in-law...that would by Nosey Rearend) It makes the most noise between 45 and up. It's sort of a "scr-scr-scr-scr" sound, and you hear it best when you ease of the gas and it's just in that area between accelerate and backoff. I have tried pulling up on my "E" brake at speed to see if that was the noise, but it didn't change at all. I don't know if it's a wheel bearing or differential. Any advice??... Oh...it's an 81 Vette.
Thanks in advance
Fred

how are your u-joints ???

Take a look at the rear brakes. You could have some wear or material stuck in the pads causing this. You can lift the rear of the car in the air, support it on stands, block the wheels, and run the car then listen for the source. Use great caution for rotating parts. They hurt.

Thats sounds more like a pinion bearing or the axle bearings. I've had this same noise occur on two other cars and both times it has been bearing in the diff or in the axles.

I would check the small things first, but thats my guess. Let us know what you find out.

Yeah... I'm almost afraid that it's the "Pinion" myself...It has the right revolution... Either way...it looks as if I'll have to drop th' rearend... Thanks Fellas...

Sounds like a possible pinion problem to me to. Hope it's simpler than that. But be glad that our style (80-82) rear ends are quite easy to drop out of the car compared to '79 and earlier vettes. What gear ratio are you running? 2.87,2.72 or higher. I had 2.72's in my '81, then I had an '80 3.08 rebuilt and put that in. It was a little nicer coming off the line yet keeping the rpm's low on the highway. Now's the time to improve things back there if that's the problem. Good luck!
Sarge

Sarge81;
Good Morning, and how are you?. You mention that our rearends are easier to remove...can a novice like myself do it?. Remember...I'm a Locomotive Engineer ...not a mechanic. Although I did change my own plugs and wires as well as remove-clean-scrape-paint my valve covers. I suppose that if I go through the trouble to remove my diffy...I should go ahead and have it rebuilt. And replace the "U" joints on the driveline and stub axels... If I do it myself...do I purchase an AllData CD or get a Haynes manual? I'm open for suggestions...

Ol'Scratch said:If I do it myself...do I purchase an AllData CD or get a Haynes manual? I'm open for suggestions...

I would say remove yes..

but rebuild... I wouldnt try it without being an experienced mechanic..

Great Scott NO!!... I wouldn't dream about rebuilding the Diffy all by my lonesome. I'd probably take it up to "Oregon Driveline" in Portland. I had them repair a "Jag" differ for me once. But if there's nothing tricky...I should be able to put'er on stands and remove it myself...
Thanks fellas for the replies

Ol'Scratch, I'm sure you can do it yourself.
1. Get the rear of the car up in the air via a lift or up on jackstands.
2. Pull the rear tires off
3. Drop the exhaust out the way.
4. Unbolt your driveshaft and halfshafts.
5. Clamp a block of wood towards the outer end of the leaf spring to keep a jack from sliding off. And jack up on the end of the spring relieve tension off of the spring bolt. Undo the spring bolt. Slowly lower the jack. Repeat for the opposite side. Then remove the 3 bolts that hold the spring to the diff.
6. Remove the strut rods and bracket.
Note: Remember to mark the position of the camber bolts.
7. Unbolt the front diff mount.
8. Support the diff with a jack or an extra body.
9. Remove the 2 bolts at each end of the diff structure. And slowly wiggle it loose, lowering it down and out.
10. Put the diff. nose down in a old 5 gal bucket and zip the bolts off that hold the "batwing" structure to the diff housing. Then you can carefully drain the gear oil out. Send it out for overhaul.

I R+R'ed my diff in 4 hrs. myself. On a lift.
Sarge