Keoman

iTrader: (3)

So...

I was driving home in the evening the other day and all of the sudden going around a left hand corner the rear end of my car starts making a horrible intermittent clacking noise, probably about every rotation of the tire around the corner.
I'm freaking out with every clunk it makes until the car straightens out and stops making any noises at all. Luckily i was in the middle of almost-nowhere so i pulled back on the road and tightly turned the car RIGHT and pulled it forward very slowly. Nothing. Backed up and turned it LEFT... yikes.. more clanking.
What the hell is going on??

I must mention that the car has been making another noise in the rear for about he past year.
When it happens: Going in reverse and applying pressure to the brakes. (it gets worse if you turn the car to the right while braking in reverse) It almost seems to be coming from the brakes themselves.
What it sounds like: I could best describe it as like a harmonic vibration. It almost "moans" but nothing terribly awful like yesterday.

Please Help!

mike_c

iTrader: (13)

What kind of rear do you have? Is it a 9 bolt?

As for the second problem, my car used to do the same thing. And then I put new pads and rotors on the rear because they were shot. After that the noise stopped. How do your rear pads/rotors look?

Keoman

iTrader: (3)

Yeah mike, its a stock 9 Bolt G80. The pads are great and the rotors are also in good condition however i guess they could have gotten a couple MM play in them over the years between the Lug Studs and the actual disk and might be vibrating. I would bet that if i replaced them it would go away. Thanks for the advice.

update: So i got the diff cover off today and drained the fluid and the pinion gear (is that what its called? the one connected to the drive shaft) and the planetary gear look awesome, no gouges or scrapes or rub marks or anything, clean as new.
I really need to get a look at the spyder gears. Do you have to completly remove that gear housing inside the diff to look at them?
Also i dont know if the G80 is different than normal. Posi? I am learning as i go so any input would be much appreciated. I dont plan on actually rebuilding the stuff myself but i want to drop the rear end and paint it, it needs it and now that its broke...

Come on guys i gotta get this fixed ASAP

85 ZXX

iTrader: (1)

Here is a start for you: http://mpikas.blogspot.com/2008/03/r...rner-cone.html


https://www.thirdgen.org/bw_9-bolt_cone_repair

Thirdgen Ranch sold me a 9-bolt rearend that was suppose to be good, but they lied. The carrier was total junk. Two spider gears were seized to the cross shaft and broken, carrier halves were waller ed out where cross shaft fit into. Posi cones were slap a** bottomed out. A total F**king junka** piece of Sh*t rearend that I got from them. They ripped me off!!! Do allot of research on the 9-bolt before you buy any parts, especially used.

mike_c

iTrader: (13)

Since you already have the cover off, take a look at this picture and compare it to your rear:



If there's very little or no clearance in that window, it's time for a rebuild/re-shim, or replace the whole thing...it's up to you.

Check out this thread: https://www.thirdgen.org/forums/tran...oise-when.html Is this similar to what you're experiencing?

Keoman

iTrader: (3)

http://mpikas.blogspot.com/2008/03/r...rner-cone.html

Ok so I got it all out tonight. *For anyone wanting to know, on a 9 Bolt there are no c clips, you just have to take off the 4 backing plate bolts near the rotor and muscle the axle out of the shaft.

I was able to take a lot of pictures and i would be greatful if someone would look at them that knows what they are looking for. The pinion gear looks great as well as the planetary gear. However the spider gears inside look a little worn down. There were a couple of metal shavings in the bottom of the diff cover which leads me to think there is something amiss.
All hardware is bagged and labled. Thanks for all your help guys. I know absolutly nothing about rear ends but Im a quick learner as long as there is someone to shed a little light.

TGO you rock!

Pics:




This is the one that alarms me, can you see the gouge on the inner metal peice there? Is that normal?




The teeth here on the inside looked a little worn off, hard to see in the pic but maybe you can get the jist.



Also another thing that caught my attention, this is the passenger side. It was covered in grit while the driver side was clean as a whistle, actually a little surface rust on the drivers from 0 grit buildup.

Keoman

iTrader: (3)

And here are the numbers.





Not sure exactly what this is... looks kind of non factory to me..

85 ZXX

iTrader: (1)

Looks like series 2 carrier with 2:77 gears...Since you are this far, keep going and disassemble the carrier halves and check the cones, and spider gears...you are doing great so far.

Keoman

iTrader: (3)

*EDIT
nevermind about explaining the carriers, https://www.thirdgen.org/forums/tran...ml#post4834919 double

Can you tell me more about seriesX carriers?
After reading that atricle again, looks to me that my Cones are very close to the housing on either side. Definatly some rubbin going on there.

85 ZXX

iTrader: (1)

Take the halves apart and and inspect...its easy...try to remove the 7/16 evenly and mark both halves with some paint... after both halves are separated, remove the spider gear assembly and you will figure it out. if the posi cones are bottomed out try to machine them down around .030 and install in the half and see if it grips and has a gap in the window. if so, reassemble and add shims to compensate. set the spider gear assembly back in the half, the cross shaft needs to rest flat on the half. remove or add shims as necessary. Do both sides then reassemble and use blue locktite on bolts.

Keoman

iTrader: (3)

Bad News

All torn apart and i found some nasty suprises.
The passenger side stuff was all kinds of smashed up and grinded off...


Notice the chunks of metal on the side...





This is the passenger side gear. BAD




Passenger Cone, salvagable?




Lots of pitting on the back side of the cone and the gears




The spider gears all resemble this one. Chipped and grinded off.




The chunks of metal i pulled out of the case YIKES
You can also see the drivers side gear in this picture, if you notice, its pretty solid. It has some pitting on the teeth faces however and will need to be replaced too.




So what do ya'll think...
Fix or RIP?

4th gen swap?

12 Bolt swap?

I would like to be practical but if im going to be tinkering, better to upgrade than stay the same... at least i think.

mike_c

iTrader: (13)

It's gonna be a gamble with used parts, you could make out ok with a used 4th gen rear, or it could end up needing a total rebuild like yours. I'd expect to spend at least 1K for a total overhaul of your 9 bolt. Just looking on spohn's site, a Moser or Strange 12 bolt is right around $2000.

If it were me, I'd rebuild the 9 bolt with a 3 series carrier and a 3.45 gearset and call it good. Not going to be as strong as a 12 bolt, but it'll hold if you don't have really serious power and aren't launching on slicks.

At the end of the day though, it's up to you.

If you do decide to rebuild what you have, check out ebay Australia, that's where I got a NEW 3 series carier for my car when mine bit the dust. Price wasn't too bad as at the time either. but that was a few years ago...

85 ZXX

iTrader: (1)

Ed Miller has the adapter plates to convert a 10 bolt drum rear end to the PBR brakes that you have. I would search for a 10 bolt in your area (easy to find and cheap) and make the swap to get you going again ASAP. After you have done that, you may decide to go through with rebuilding the 9 bolt from one end to the other.(It will be expensive) Check www.flynbye.com.

With gas prices rising by the hour, a 10 bolt 3:08 rear end would be a great temp fix to get rolling again and make a great spare just in case. I have two 10 bolts and the POS 9 bolt....My car has the 10 bolt 3:08 the spare 10 bolt has 3:42 and rebuilt 9 bolt has 3:27.

I've got over 1K invested in that POS 9 bolt that I got from Thirdgen Ranch and I still don't have it painted yet.....

85 ZXX

iTrader: (1)

This is my dream diff rear end.......

http://cgi.ebay.com/ebaymotors/9-inc...Q5fCarQ5fParts

85 ZXX

iTrader: (1)

I'm afraid it bit the weenie (RIP) Totaled out!

Keoman

iTrader: (3)

Well i ended up getting a 3 series carrier assembly with 3.70 gears completly rebuilt on ebay for a pretty good deal! Cant wait for it to get here! should be here around thursday this week.

85 ZXX

iTrader: (1)

Here is a pic of the junk I got from Thirdgen Ranch that was suppose to be good.

matthufham

iTrader: (5)

how did you not see metal in there the first time. the spiders are almost bald! but looks like you got it figured out now

Keoman

iTrader: (3)

The first time? This is the first time i have ever taken it apart. I have been a naive clueless child about rear ends until now. But live and learn right. Wont happen again.

A little update; parts came and i have been in the process of painting the rear end and getting it looking like it should go in a camaro again! Cleaned it out tonight and it doesnt even resemble the same rear end! I wire wheeled it all down (PITA, would sandblast/powder coat next time) and hit it with a coat of Self Etching Primer first (grey), next epoxy primer and finnaly a coat of gloss black we had laying around. I wasnt quite sure of the gloss on the rear end but i can actually say i like it. Looks sharp. Cnat wait to start reassembling!
Check it out.

Oh BTW, i went ahead and ordered a TA diff cover to finish things up right. Should be here this week.

85 ZXX

iTrader: (1)

Nice Job! I've been inspired, I painted mine today and put the new rotors, PBR calipers, braided flex and hard lines on. I still have to change out the proportion valve to a rear disc one. My car still has the rear drum brakes on it.

I'll send a pic when I get some time off.

mike_c

iTrader: (13)

Lookin good! And nice buy on that carrier. I had my eye on that too.

85 ZXX

iTrader: (1)

Someone has a "69 work in progress" in the shop...Is that your Dad's car?

Keoman

iTrader: (3)

Its my buddies shop, its actually one of 3 first gen camaros in there right now. Those and his 70 chevelle haha... too much money..

Ok so for an update, I was able to get everything figured out. I had to play around a lot with the shims and the specs to get the 3 series to stop whining after i put it in, but this morning I got it all installed back in the car and took him out for a spin, SOUNDS GREAT. Thanks for your help guys. I appreciate it.

I guess i should have posted all this in the same thread, but here is the shim tinkering thread.
https://www.thirdgen.org/forums/tran...0s-really.html

Keo

Good Times

85 ZXX

iTrader: (1)

For Keo,

I put some Supertech 90-140 from Wal-mart in my 9 bolt and it is smooth and quiet with no leaks.

keeslinger31

okay?

85 ZXX

iTrader: (1)

For Keo,

Twin Turbo was right about about the standard hypoid gear oil with the high visc. The posi works great and no friction modifier of any kind was needed.

dimented24x7

iTrader: (2)

WOW! Ive never seen cones wear that much before. I always wondered what would happen if they wore to the point that the spider gears would have too much backlash.

How many miles where on it?

dimented24x7

iTrader: (2)

Also, how did the new carrier look inside? When I took mine apart, even after all these years the cones where still within factory spec. My rear came out of a secretary's car that ate a telephone pole, so it all depends on how theyre treated. Dont get too crazy with it and the cones will last a long time.

dimented24x7

iTrader: (2)

I used that as well, but in the winter (not a problem where you are), the rear would turn into a one wheel peeler. I actually ended up getting trapped on ice in the middle of the road at one point. It just wouldnt lock up with the thick stuff.

85 ZXX

iTrader: (1)

Check this junk posi that I bought from ThirdGenRanch that was suppose to be good.