nesluopetan

ok, this is what its came down too, is it true?

mechanic couldnt figure out why my car was grinding when turning after he added my new ring and pinion., he called some big wig in washington, and he said camaro axles from 89-92 are a little TINY bit wider than 82-88.. so thats why mine is grinding, because i took out the 28 spline axles from the 89 iroc, and put them in my 82's rear, with the posi carrier and brand new 2 series, 3.73 gears, so thats why when I turn, it clanks, is because my axles are not snug, and its clanking back and forth, so yeah, im screwed... i have spent almost 1k on this rear, and I am not one inch ahead of when i started, its been a total living hell from the start. I NEVER HEARD ABOUT TWO DIFFERENT AXLE SIZES.. I thought they were all the same width.. what the hell? what do I do now? my rear end works great except when I turn.. should I shim it? can I grind down the axles a little? what is the actual width difference between the axles? let me know my options, i am SCREWED, UPSET, ANGRY, AND OUT OF MONEY, and I desperately need your guys help. please. No rude comments such as "SHOULD OF GOT A FORD REAR END" or things like that.. whats done is done, now Ijust need help getting it to work.. please post what you can to help.. thanks guys. I need it!

Nate

84 Z-28 350

all the axels from 82 - 92 are the same legnth it's the spline thats diffrent 82-87 1/2 are 26 spline and 87 1/2 to 92 are 28 spline - a 26 spline axel WILL NOT FIT in a 28 spline carrier (unless a really big hammer is used ) and vise versa. they changed the legnth in '93.

ede

far as i know there is no differance, other than spline count in third gen axles. i'd say there is a better chance whoever set the gears up missed something.

Zepher

iTrader: (1)

If you haven't added the GM Posi additive, then I'd suggest you do so before you damage the rear. Costs $7.00 or so for the bottle. It is made to lubricate and quiet the posi unit.
This additive is required.

82camaro

Sounds like he couldn't figure out the problem, so he blames it on the fact that you swapped out the axles.

sleeper

This guy sounds like a moron... quit listening to him and go to the manufacturer of the gear and pinion. Ask them what they think.

Who's the bigwig in washington? His other brother Larry?

nesluopetan

It is Randy's ring and pinion, in washington.. They said the axles from 89-92 are a tiny bit wider, thats why when I turn, it slops and clanks and makes a horrible noise... thanks for the reply, keep them coming, i dont know what to do... i used the 28 spline axles, and the posi unit out of the 89 rear, and put them in my 82 rear, and bought me the 2 series 3.73 gears. so everything should work, the posi unit looks to be MINT cond, no bad wear marks or anything, i just dont understand what is clanking... any other ideas? I need to go to the shop today and tell him what I want to do now, and im out of money!!!! help please.



Nate

nesluopetan

please anyone??? offer ideas please... i need all your help and tech experience.

Zepher

iTrader: (1)

One question, do you have a 9 or 10 bolt? 9 bolts don't need the additive, 10 bolts do. Maybe Mobil 1 gear oil doesn't need the additive, but I do know for a fact that without the GM additive the diff will make noises while turning.

I'd put the additive in there, if the noise conitinues, then change the axles.

TomP

I replied on the drivetrain board already; but I just thought of something else- did Randy's mean the axleshafts were longer, or the axle assemblies themselves? If they meant the axleshafts, it shouldn't matter, because as far as I've ever known, all 82-92 axle housings were exactly the same.

And what kind of shop did you go to? A "general" garage? Maybe if you found someone, like a 4-wheeler (off road truck) garage, that did a lot of work with axles and gear swaps, they could find the problem better. I have a mechanic that I trust for just about everything- but for alignments and brake problems I can't fix, I go to my tire/wheel shop.

nesluopetan

sorry, im just frustrated, my bad, the rear end does not grind whatsoever when your going stright, only when you turn. its an awful sound. its the sound that makes your butt pucker when you hear it. The actual posi unit looks to be MINT cond, brand new bearings, etc... nothing wrong that I can see. great posi fluid, evetything seems tight. how come randy's said that the axles were longer in 89 - 92 rears? he said thats why its clanking when I turn, because my axles are sloppy.. is this true? i just dont know where to go frmo here, ive spent so much money, and I am not one inch ahead than when I started.. thanks for the replies keep them coming please... the guy thats doing this is in a tire shop, but this specific mechanic is VERY good, he has redone probably 1000+ rear ends, worked for GM, does jeeps, etc.. and he just dont know what is going on, he is flustered too... any more ideas?

Zepher

iTrader: (1)

You haven't answered my question, did you have the 8 or 10 (can't remember the amount that is in the bottle) ounces of posi additive added to the gear oil? Without the additive the rear will be really noisy when you turn. The additive lubricates the clutch packs in the posi unit.

TomP

Or, my question... did Randy's say the axle assemblies were longer, or just the 28 spline axleshafts? Either way, it doesn't really matter, because people have done this swap before (28 spline axles in an 82-88 rear axle assembly), and they haven't had problems.

I can't see how the axles would be "sloppy" in there, anyway. The c-clip locks them in from moving outward. The lock pin keeps them from moving inward. I don't get it.

Unless, he meant the axleshaft is too long, and it's not mating correctly with the axleshaft bearings? But hell, you'd hear weird noises no matter which direction (forward backwards left right) you were going!

Omega

iTrader: (1)

I read in a drivetrain manual that the c-clips can actually wear out over time. That would make the axles a little sloppy. Try replacing the c-clips. Did you replace the bearings at the ends of the axles? That also can make the axle move around more enabling the rotor to scrape on the caliper cage.

I really don't think that the axles are different lengths. I put a set of 91 axles in an 85 rear and they worked fine.

Do you have a drum or disc rear? If you have a disc rear, jack the rear up and take the wheels off. Pull on the rotor and turn it as the same time to see if it rubs on the caliper cage. Do the same when you push on it. That would tell you if the axles have too much play and are scraping.

84 Z-28 350

If you haven't already done so change the fluid with DYNO OIL (non-synthetic) and put the proper GM BRAND (nothing elts works) synthetic oil IS NOT compatable with cirtin types of posi's and aftermarket fluids have the same problem thats what happen to mine and it took me 3 fluid changes to figure it out (yah I know- I'm a duma$$) and it was doing the some things you discribe. also you were told to take it easy for the first 200 miles and than change the fluid- right? if not do that 'cause if you try to run it hard you'll anneal the gears and they'll be noisey forever, and the fluid should have a silvery apperance the first time you change it.

nesluopetan

well tonight i took it upon my self to change the fluid, but i did not read your post in time, so I jsut went to auto zone and got some generic fluid, with generic posi additive. I put it all in, took forever with no lift, and then I drove it around, sure ****, after 20 min of driving, it started a clanking and moaning and churning like no other. people is saying that since its limited slip, maybe its not slipping when cornering, thats why its moaning like this. The depth, and ring and pinion is set up perfect, I even checked it tonight, everything is tight and snug and has a tiny bit of play, just how it should. do you think I should buy another posi carrier?or honestly do you just think its the fluid i used? these are some AWFUL noises, they are HORRIBLE.. sounds like metal on metal scraping, and churning, rubbing, etc. this is the thing, when I took off the cover tonight, and got out all the fluid, there was not one ounce of metal shavings, whatsoever! so how in the hell is it grinding like this, but everything is still tight and perfect when you look at it? obviously after driving for 20 min, its heating up and the friction is causing all these noises, or the limited slip is not slipping? I have a chance to buy a new posi carrier for cheap, should I do that, or do you honestly think it is the fluid brand? can you explain the noises you heard? and were they so horrible that your butt puckered and your teeth quenched when you heard it? like i said, the ring and pinion and axles are fine, everything looks good, it drives perfect when going stright, only makes noises when you turn, WTF should I do guys? please post ANYTHING.. ill be up for most of the nite, so I will instantly read your posts and reply.. please keep them coming..

Nate

nesluopetan

PLEASE ANYONE?? im slowly getting tired, and want to know if i have any hope on this rear end before i go to bed.. please reply

84 Z-28 350

try putting GM fluid in it mine chattered after putting autozone fluid ( the one in the tube kinda like a toothpaste tube but after I puta some cheap dino oil in it and some GM addive in there it was fine.

nesluopetan

u honestly think that will fix it? where do I buy this dino stuff and GM posi stuff?

nate

84 Z-28 350

dino oil is just non synthetic oil wich you can buy anywhere and the GM addive you have to get a a dealership (sorry we all hate going there).

Zepher

iTrader: (1)

Omega

iTrader: (1)

Did you have the outer axle bearings replaced?

Do you have disc or drum rear?

What kind of posi unit do you have? Cone, clutch or what?

Read my post above and post the results. It won't take that long to do. I don't think that your problem is in the pumpkin area.

nesluopetan

I have drum breaks. I know he replaced some bearings but im not sure which ones.. It never did this when I had my 2.73 in there, with 26 spline and open rear. It is the cone posi unit also. the play is just about right with the tires, everything looks to be good and tight in there.. no metal shavings what so ever.. what ya think?

nate

anesthes

iTrader: (12)

Hey,


For the record, the 9-bolt "spin resistant diff" requires posi additive. It says so on the tag.

Anyway, you need someone to stand on the inside while turning and watch what your wheels are doing.

Also, does it do it when you turn in reverse?

-- Joe

nesluopetan

well guys, I called my main mechanic that put together my engine and tranny, they have been in business for 35 years. I toldh im what was going on, how it was clanking, etc.. and before I could finish, he said, "NATE, I KNOW WHAT IT IS FOR SURE". Im like, Paul, you didnt even let me finish explaining it, and he said I dont need too, I know what it is. He said its my posi fluid, for SURE. He said he sees this all the time, he said for GM limited slip rear ends, you HAVE to have the ford or chevy limited slip fluid.. he said 95% of the time it will grind if you dont use GM or FORD fluid. He reassured me thats what it is, he said it happened to him personally, and changing the fluid to the correct one is what it is. he knew the exact sounds, that is soudns like your rear end is falling off, and grinding the hell out of the rear, he knew it all, and said thats for sure what it is. So what the hell, I will go try it tonight, if that does it, I will be VERY happy, but very pissed at the same time.. know what I mean? The axles have a tiny bit of play, just how they should, everything looked good and tight, etc. so hell, this could be it.. ill keep you posted.. thanks guys!

TomP

Guess ya should've called him earlier, eh?

Good luck with it, let us know how it goes...

88IROCARMY

Well til we get an update here are some lessons I learned

1. 28 spline axles are wider/thicker than 26 spline axles BUT only on the body, the bearing contach diameter is same as 26 splines. The increase to 28 slines also increase the width of the spline ends. Take a 26 spline into a 28 carrier and bounces around.

2. MOBIL 1 synthetic gear oil, when I used it on my high mile 10 bolt auburn factory rear it souned like monkeys with hammers. I used the additive!! The synthetic did not provide shock cushion like standard 90W. Changed to 90W noise was gone in 10 minutes with additive. Wasted money for nothing Use the standard oil, Actually Penzoil makes a gear oil with limite slip additive already included.

3. Axles will have about 1mm of in and out movement. Can be reduced by using new C-clips, since they wear and slightly bend.

4. Like with any used part, a used carrier can be a gamble. You can always go with the SLP unit.
I think your noise is because of the fluid or bad clutches in the Posi.
Goo luck

Zepher

iTrader: (1)

See, I told you it was the Additive. One of my rear ends did the same thing when we did the gear swap.

nesluopetan

been driving it all nite, i think i still have a problem.. it is not grinding, but this damn rear end is HOT. I bet you can fry an egg on it, you cannot touch the differential cover for more than 1 second or it will burn your finger.. is that normal with posi? why would it be getting so hot? like I said, its not grinding, but i dont think it should be that hot at all, when I looked at the gears, everything looked very good. is this normal? or should i start worrying? keep em coming, were almost there!

nate

Zepher

iTrader: (1)

You should have a vent plug on the top of the pumpkin, make sure you have it there and not plugged up. Plug is a little white plastic thing, it just slides right in. Make sure it is there and it is clean, or else buy a new one, costs $2 from the dealer.

nesluopetan

would that cause it to get that damn hot? this thing is HOT.. i bet its as hot as my headers.. I heard rear ends run around 170 degrees, is that true? this just seems tooo damn hot for me..

Nate

I need a rear end cooler, too bad they dont make them, run it through the raditator, :-)

Zepher

iTrader: (1)

I do know that if that hole is plugged it will get very hot and start burning up the gear oil. I haven't touched my rear end after a drive to see exactly how hot it gets, I'll see how hot my brothers T/.A rear gets tomorrow after a 25 mile drive.

nesluopetan

k please let me know, also where is that breather hole exactly? how big is it? please describe all that.. any other opinions?

nate

nesluopetan

hey one more question. how come tonight driving around 40 mph, it feels like my brakes all of a sudden engague very lightly, then let off? for instance im going down the road, and all of a sudden it acts like its braking for just an instant, very lightly, then it resumes to regular speed.. what can cause that? its a brand new tranny, i dont think that could be it.. any ideas on that? it feels like your letting on the gas, and off the gas, when im holding the gas the same all along.. please let me know.. this little phucking crap drives me nuts!

Zepher

iTrader: (1)

I have no idea what could be causing that without experiencing it myself. Does it happen in "D" or "OD" or it doesn't matter which gear you are in?

84 Z-28 350

are the tires the some type, ware and, inflation pressure 'cause if not the limeted slip will just keep on slippin and cause allot of heat along with wareing everthing down fast

wasp

ive always been told synth gear oil is a :nono: in rear ends , its too good and doesnt let the gears mesh properly..........

nesluopetan

yeah tires all all the same, etc. remember, I had heat problems in the rear end, and just added 3.73 posi.. What in the rear end can cause this? what isnt right? please help guys, I am very frustrated..

nate

84 Z-28 350

how hot is it, is it like boil the oil off hot or is it just hot to the touch, I just did a similar swap (about 2mo ago) and mine is hot to the point where you can't touch it but it work's great, but it's not hot enough to burn the oil off. also try putting one of those allumnium rear end covers, that's my next step, 'cause allumnium is highly conductive and will pull heat from the fluid, the reason I need one is 'cause of rear end, and rear end bering flex wich the cover should fix, hopefully

nesluopetan

dumb question, but how do I know when its hot enough to burn the oil off? the oil is inside the cover? this thing is hot, you cannot even touch it. you touch for 1 second it hurts your finger. as far as the breather cap, I cant find it!, people told me its on the top of the pumkin towards the drivers side. What does it look like exactly? is it metal? please emphaisze on that for me. as far as it braking on me, it is just the th350 trans, it does it in drive, but I have not tried it in other gears. it seems like it only does it after the car has been warmed up really good.. can it be the posi unit? transmission? what do you think it is? please reply guys, I appreciate it. whats the normal temperature for our rear ends to be at after a long drive? anyone measured the heat before? please post any theories or ideas.

84 Z-28 350

like if you, pull your dipstick out while the engine is running and touch it, is it that hot. hotter than that is bad that hot or cooler and it's good. the vent is a white plastic pice with a green cap that you should spin around freely. it's on the drivers side about where the axel shaft meets the pumpkin

cp87GTA

You should be using pertoleum based oil WITH GM posi additive. Your rearend will run hotter while breaking in. You installed new gears right? Did your mechanic break them in? Or bother to tell you how it should be done? New gears need to be broken in, and they will run much higher temps durring this time. First run should have been 20 to 25 minutes and then a complete cool down.

84 Z-28 350

that's diffrent than what the place I went to said, there a driveline only place and they said take it easy for the first 100 miels or so and then change the fluid after 200 miles. oh well 2 ways to get to the same means.

nesluopetan

well it was dark tonite, but I do not recall seeing this plastic breather cap with green top piece anywhere.. I didnt see or feel anything that looked like that. how far does it stick out? how do you change them? yes, the ring and pinion are BRAND new. I am following the break in procedure, I drove it 25 miles, let it cool down., then ive been driving it normal since. I heard to go easy on it for at least 200 miles. but why did my car start acting like the brakes are sticking then unsticking? that doesnt make sense! i dont think its a bad posi unit, beacuse it doesnt do it when cold. (pretty sure it doesnt, i drove it around today for 10 min, and it didnt do it) so i think its just when its warm, wtf can cause that? so maybe changing my breather cap will help the warmness, but what about the braking? what ya think, you guys are awesome, keep em comin please.

nate

Eggplant Jeff

Axles in old housing NOT a problem, I'm running that right now. 28 splines will NOT fit into a 26-spline carrier even with a big hammer, 26 splines will slide into a 28 carrier and just bouce around, totally loose, not even close to a fit. However EITHER axle will fit ANY 10-bolt housing. And C-clips really don't wear that much. Mine had 160 thousand miles on them when I pulled them, they had wear marks on the surface but it wasn't like they were worn down by any noticable amount.

The breather cap is not easily visible by looking from the rear of the car, it is on the front/top side of the pumpkin. It is "white" but may be completely dirty and crud covered... It has spent its life on the outside of an axle housing :-). It sticks out of the housing by 1 to 1.25 inches. Just get under there (car jacked up) and look around. Know where the filler plug is? Start there and work your way UP toward the top of the pumpkin and OUT toward the passenger side axle tube. If the breather isn't there you should find a hole, or a plug, or something. There aren't that many holes in the pumpkin you'll find it sooner or later.

I'm running the SLP Torsen "posi" with no problems, it has Mobil 1 synthetic right now... I don't think it sounds any different than when it had Exxon SuperFlo (non-synthetic) in it. But the Torsen is not a Posi in the normal sense, no clutches or cones, it's all gears. Interestingly enough the SuperFlo had turned green when I drained it out. Not sure what that means? I think I'll probably just use some generic non-synthetic oil next time I change it.