Irockthedrag

Having some serious issues with my rear end. I have a half inch to an inch of play in and out on both rear axles, car just makes a clunking noise when I try and drive it, if I push the axles in I can drive somewhat. The gears inside are all chipped ground and rounded. The two metal flap type things in the center just free float and move around. I have very little experience with rear ends but if someone can help me diagnose and source parts I'm confident I can repair it. Here's a few pics with the cover removed. It's 3:73 gears posi disk brakes.


You know what, think it's a locker. When jacked up in neutral if I spin one tire the other spins THE SAME WAY. With the gears the way they are and the play in the axles if i don't push the axles in the whole way before turning them it'll just free spin.

red rock

iTrader: (2)

Here is a wealth of info about the 10 bolt rear. https://www.thirdgen.org/forums/tran...-10-bolts.html

zero13

i have a pair of OEM axles out of my 91 z28....if youre looking for a nice set...

big gear head

You have a seriously damaged Auburn differential. It's scrap metal. You need to replace it with a new Eaton Posi. Read this. http://www.nastyz28.com/forum/showthread.php?t=19773

Irockthedrag

So if I buy a new carrier will that be all I need? I've been reading up on all those links but I have almost no experience with rear ends and if I have to pay for it to be done this car won't see the road anytime in the foreseeable future. I can afford parts, can't afford labor and with little instruction I feel like I can handle it.

sofakingdom

iTrader: (1)

You'll need the carrier, bearings, and shims.

Pretty eeeeezy job, really. As long as you don't have to touch the pinion gear it's cake.

Irockthedrag

It looks like pinion is still in decent shape. Any recommendations on what I should purchase? I'm not looking to go crazy on this 10 bolt. I'd like to keep my 3:73 gears and have posi but that's really it. My project for next year is a 9 inch but I don't want my car stuck in the garage until then.

Irockthedrag

I think i found the diff you were referring to but not sure if this is the correct kit..

Here's the carrier:

http://www.ebay.com/sch/i.html?_odkw...aring&_sacat=0

Here's the master kit:

http://www.drivetrainshop.com/Yukon_...%20gm7.5-b.htm



Also is the bearings and shims specifically for the eaton or can I just search for a gm 7.5 10 bolt master bearing kits?? If that is the case I also found this:

http://www.ebay.com/itm/GM-7-5-10-Bolt-Master-Bearing-Installation-Kit-NEW-Fits-1982-1999-/221458531893?pt=Motors_Car_Truck_Parts_Accessories&hash=item338ff50635&vxp=mtr

rusty vango

be careful of e bay parts. its hit or miss. call up "randys ring and pinion" try and get all the parts for it in one place to avoid a possible mis match.

big gear head

If you want to shop ebay then look up a guy using the name monzaz and buy from him. Ask him about the Yukon Dura Grip. It's a little cheaper than the Eaton Posi and works just as well. Also get the differential bearings, shims and ring gear bolts from him. You don't need a completel rebuild kit. There is no need for you to remove the pinion if it was installed correctly and there is nothing wrong with it. Just follow the instructions in the link that I posted above and you will be all right.

Irockthedrag

Yeah I was just trying to keep cost down and was having trouble finding what I need elsewhere. As an afterthought wouldn't I also need 28 spline axles with these carriers? I have an 83 so I would have 26 spline.

big gear head

You can get them in 26 or 28 spline. If you can afford it the 28 spline upgrade is recommended.

Irockthedrag

Found monzaz, and I found this:

http://www.ebay.com/itm/10-bolt-7-5-G80-GM-POSI-S-10-CAMARO-SS-7-625-FIREBIRD-IMPALA-LSD-RS-28-SPLINE-/261559098701?pt=Motors_Car_Truck_Parts_Accessories&hash=item3ce6231d4d
Not only is it the eaton but it's a 28 spline, guess I'll just have to get my hands on a set of axles. All I'd have to do to use it is swap the axles right?

Irockthedrag

Zero13, how much were you thinking on those axles?

rusty vango

IF your pinion gear is ok with NO damage, AND you need to wash out the housing.the pinion should have no wiggle .but any damage will be apparent. and if your ring gear is un damaged .you should be able to just use it on the new carrier. HOWEVER I defer to "big gear head " and "sofa king". they are the go to guys as far as diffs are concerned.

big gear head

That's the right guy, but the wrong differential. That one is a Eaton Governor Lock. You don't want it. Contact him and ask about the Yukon Dura Grip or Eaton Posi. You also want the super shim set for setting the backlash and bearing preload.

Irockthedrag

Once again thanks! I contacted him earlier and I'm just waiting for his reply..

Irockthedrag

There's an eaton posi true trac that has no clutches in it and it's not supposed to wear out, then there's another one that's just the eaton posi that says it's heavy duty internals and carbon fiber clutches.. Do I want the tru trac eaton posi or the other one?

Irockthedrag

I think i answered my own question... I've been doing research since I made this post.. Pretty sure I just need the regular eaton posi, not the one with tru trac...

big gear head

There is a Eaton Posi, a Eaton Truetrac a Eaton Governor Lock a Eaton E Locker and several others. Only one of them is a Eaton Posi. The Eaton Truetrac is not a Eaton Posi.

Formula 305

Gov lock is junk. Find a torsen LSD, they came in 99-02 Trans Am & SS Camaro's. No clutches, no additives in the fluid, only gears to wear, best bang for your buck & the operation is very nice.

Irockthedrag

The description on the item was pretty misleading, it actually said eaton posi with tru trac. The eaton posi is around 500 shipped.. That's roughly a third of the 9 inch build I was gonna do next year. I was hoping to get it back going for less then 300.. I just feel it pointless to do this twice in less then a year. I am actually working more hours just to cover the extra money I've been spending on my camaro and specialty tools. I've sunk about 2k into it in the last 2 months. Fiancées getting pretty angry... Oh well!! I just bought her a new car anyway.

On another note...
What's the difference between the tru track and posi?.. Other then the lack of clutches and wearable parts. Eaton claims it to handle high hp applications and is little to no maintenance along with it functioning as a normal posi would.

big gear head

Posi is Eaton's trade mark name for their clutch type limited slip differential. All of the differentials that I listed above are limited slip differentials (LSDs). Each one uses a different device for transfering power to both wheels. The Eaton Posi uses clutches while the Eaton Truetrac uses worm gears for resistance to slipping. The Gov Lock uses clutches with a cam and governor to lock up when one wheel starts to spin.

Formula 305 has a good suggestion. The Torsen can usually be found on ebay for less money than the others. You must upgrade to 28 spline axles with it because it wasn't made with 26 splines.

Irockthedrag

I found the whole shabang for 299.99+ shipping:

http://www.ebay.com/itm/GM-7-5-7-6-7-5-8-342-3-42-Gears-Torsen-Posi-10-Bolt-28-Chevy-Camaro-Firebird-/281432360180?pt=Motors_Car_Truck_Parts_Accessories&hash=item4186ad04f4&vxp=mtr

Irockthedrag

I found the whole shabang for 299.99+ shipping:

http://www.ebay.com/itm/GM-7-5-7-6-7-5-8-342-3-42-Gears-Torsen-Posi-10-Bolt-28-Chevy-Camaro-Firebird-/281432360180?pt=Motors_Car_Truck_Parts_Accessories&hash=item4186ad04f4&vxp=mtr

rusty vango

now, changing the gear ratio means you will have to change the pinion gear too .NOW the specialty tools and expertise comes into play. if you can do it , fine, if you cant. find a pro. as BGH said ,you can change the carrier and use your ring gear and get by . but doing the whole lot in one go is tricky.not raining on your parade, just a heads up.

3rdgenmaro

iTrader: (9)

Im just going to throw this out there, but if you are serious about going with a 9 inch soon, I would be tempted to just swap in a full junkyard rearend for the time being to keep cost down and keep it driveable. You can find them for $150. It would be open and not the gears you want, but just an idea.

If not that, then I would suggest a used Torsen as well. Just the carrier. Use your gears, swap it yourself with some used 28 spline axles.

I wouldnt spend the money on a new carrier if you are swapping rears soon.

sofakingdom

iTrader: (1)

All that stuff about a 9" looks to me like wishful dreaming, not any kind of a "plan". I could be wrong of course, would love to be wrong in fact, but that's what's written in all that white space around it. All of that other about "fiancée", "afford labor", "extra hours", and the like, tends to mean something like, "sure would like to but it's out of reach and I'm already sick of riding the bus because a second car to drive while this one is down is also out of reach".

Just being realistic. Been around this hobby too long to look at it any other way.

Also, just think about the logic of that, while leaving a T-5 in a car.

IMO the Torsen is a good way to go. Buy that, use the carrier, sell the gears on the classifieds here as something "bought used, no idea whether they're any good or not, what you see is what you get". Prolly get at least a few coins back out of it that way without fornicating somebody else.

Irockthedrag

I don't drive this car daily, its my extra toy. I'm not riding the bus, I'm driving my daily driver. I'm picking up another chevy 350 here soon to build in my spare time without having my car down, right now I have a mildly built 383 in the car. I'm starting the 9 inch shortly after winter. I budget my expenses so I know when and what I can and can't afford for my car, whilst still affording daily expenses and bills.

Following this timeframe, I'll be able to have the spare time and money to do a build around April. I want to do it right, if that wasn't the case I'd be putting one in right now with a nodular case and stock casting.

On another note I have a torsen on its way along with new bearings and shims. Just need to source a set of 28 spline axles.

big gear head

If you can't find a good used set you can get them from Randy's Ring & Pinion or Tom's Differentials. Tom's axles are probably better quality and his prices are usually pretty good.

rusty vango

+1 on toms diffs. he has some very informative videos on you tube. watch and learn.

Irockthedrag

If I don't find anything by the end of the weekend I'll be sure to look them up. Diff should be here Monday or Tuesday.

sofakingdom

iTrader: (1)

I agree, Tom is good. He's seriously out in the woods though so shipping takes awhile. Be ready to wait a few days.

Look for Superior brand axles. Part number for your rear will be EV10-4. FAR better than Moser or other "custom" axles; not that those are "bad", just, the Superiors are BETTER. Reason is, NO metal is "hard" without heat treating, and it takes TIME to heat-treat it; and at the same time, NO metal can be machined when "hard", because it'll be as hard as the tools you try to machine it with. Since the Superiors are not made to order with a time deadline, they can make em out of REALLY HARD metal alloy that's been annealed to be soft, then instead of CUTTING the splines they can roll em, then they can send em out to get em hardened AFTER the machine work. Total turn-around time is around 4 weeks. "Custom" axles are made from metal that's hard enough to survive as an axle but soft enough to have CUT splines, and since their turn-around time is so short, that means, NO re-hardening afterwards. Just simply not as good; not as hard, not as precise splines or bearing race surfaces, no stress relief whatsoever after machining. And the best part is, price is pretty much the same. Save the "custom" axles for non-stock, i.e. truly "CUSTOM", situations.

Irockthedrag

Ive worked in machining for almost 2 years and didn't even know that. I appreciate all the good info guys. When I do my rear end swap what do you all think would best fit my application? I'm going to be putting it behind an engine that should be sitting between 425 and 475 hp. I doubt I can get much more out of a carb'd NA 383 and be cost efficient in any manner.

I'm having a hard time deciding right now if I should just pull my engine and rebuild/build it, or just pick up the 350 to do in my spare time. I have a 77 383 sbc mildly built in the car now and I have available a 350 sbc stock and running 2 peice rms for 250 I pull it. I assume I would be looking at between 1000 to 1500 for just the forged 400 crank and having the new block machined... I'm not starting any of this until October or early November so I may be driving my car very little anyhow as it doesn't see winter. Rust is hell up here.

big gear head

Have you looked at any of the 12 bolt rear ends that are built for these cars? Moser, Strange and Mark Williams all make them. They are lighter, use a little less power and are plenty strong for anything up to 700 HP.

Irockthedrag

I actually haven't. I've mostly been reading up on all the 9 inch swaps. They seemed more popular and assumed they were for a reason. I'll have to look into the 12 bolt, there's no way I could forsee this car exceeding 700 hp at any time.

Irockthedrag

So this seems to have been overlooked, but wouldn't I need a set of axle seals aswell?

big gear head

Yes, if you replace the axle bearings you must also replace the seals.

Irockthedrag

Alright, I got new axles, bearings with races, shims, and carrier. I still need the axle seals. Am I covering everything?

big gear head

Did you get axle bearings? Randy's Ring & Pinion has a axle bearing and seal kit that is pretty cheap, and they are Torrington bearings.

sofakingdom

iTrader: (1)

Seals for that rear are the most common seal on the planet. Any parts store will have it. Part # is 8660.

big gear head

Axle bearings and seals are the same for the 8.2, 8.5, 7.5 10 bolt and the 12 bolt.

Irockthedrag

The ebay seller Monzaz actually runs a local rear end and differential shop. I got all the bearings for the rear along with shims from him. Just got a mint set of 28 spline axles and seals today, and the new diff will be here Monday morning.

big gear head

So Jim is close to you? That's great. He can be a big help to you.

Irockthedrag

Less then two hrs. He supplied everything except the new dif and axles. He's just over in ohio.

Irockthedrag

Well I'm trying to take out my old diff right now and it will simply not come out. I took one out yesterday and it came right out with a bar and just a little tap. This thing is just about concreted into the damn rear end.. Anyone have some tips?

big gear head

I'm sure that you did this, but I have to ask. You did remove the axles and the bearing caps?

I use 2 bars. I put one behind a ring gear bolt at the top and one at the bottom. I pry against the gasket surface of the housing. This should break it loose.

Irockthedrag

Bearing caps and axles have been removed. I also removed all spider gear and the pin as they were in the way. I tried putting a rebar through the pin holes to "roll" it out. I just did this yesterday on a 91 and it took a total of a half hour to strip the entire rear end. I have atleast 2 hrs in on mine and still haven't gotten the bearings or carrier out. I'll try what you have suggested after work tomorrow as it's getting late.

Irockthedrag

Well my buddy stopped over to have a few beers and we got to talking and said **** it, and went and manhandled it out with the two of us pulling on it. One foot on a rebar inside of the carrier and we each had a hand on the dif, popped er right out. Tomorrow after work I'll take off the ring gear, tried the impact on it when I took it out and the bolts just laughed at me.

sofakingdom

iTrader: (1)

Right: there is supposed to be preload on the bearings. The factory assembly method is to pry the case apart with a spreader, then stack up about .020" more shim in it than the width of the space, then take the spreader off and let it press the bearings together.

You'll need to duplicate that when you put it back together. If you just shim it to take out the end play and no more, it will be HORRIBLY SLOPPY loose and noisy, and will probably destroy the gears quickly.

Impact will pop the ring gear bolts RIGHT OFF. Main thing is, they're left-hand thread; chances are, you just tightened them a whole bunch extra instead of loosened them.